A popular adage suggests we should “eat breakfast like a king, lunch like a prince and dinner like a pauper”. 
We interrogated more than half a million days of food diaries to see whether it is actually helpful.
The chart below shows the proportion daily calories consumed at breakfast versus the proportion of a person’s daily target calories consumed based on their food diaries. A score of 100% would mean that they achieved their calorie goal. A score of less than 100% indicates the individual was able to consume less than their goal intake for the day.
The data from people eating three or more times a day indicates that, on average:
people who ate the least for breakfast tended to eat more across the day, while
people who consumed more of their daily calories at breakfast tended to eat less during the day.
People who front-loaded their calories at breakfast tended to eat around 20% less across the day!
Looking at the data for lunch, we see a similar trend.
If you can fit it into your lifestyle, a larger lunch seems to be better.
Where this data gets interesting is when we look at dinner.
People seem to do OK if their dinner is similar in size to breakfast and lunch. However, we tend to overeat if we consume the majority of our calories at night.
Putting it all together
When we overlay all three meals, we see that prioritising breakfast is a good idea if you want to get or stay lean.
If you are already lean and need to recover from a hard day of activity, then eating at night will help you consume more energy and store it more effectively.
But is this result due to behaviour or biology? Or perhaps a bit of both?
It’s possible to explain why we overeat at night from a purely behavioural perspective.
It can be hard to eat a lot at breakfast when you need to get off to work or at lunch when we might be at work or school and have to prepare a lunch and bring it from home.
But then at night, we have the fridge.
We have our friends and family.
We have Netflix.
We have the perfect storm of comfort food, social eating and self-soothing combined with being surrounded by less than optimal food choices that we tend to fill our patry and fridge with.
Food eaten later also has to be stored, at least until the next day to be used when we are more active.
Locking in your circadian rhythm
There have also been a number of interesting studies looking at the relationship between food timing and how it affects our body.
Compressing your feeding window to give your body a chance to spend time in a fasted state is useful. However, it seems shifting your eating window earlier in the day is also beneficial. This is commonly known as Early Time-Restricted Feeding (or eTRF).
Just like it’s beneficial to get sunlight in the morning and not gaze at blue light from our screens all night, it seems it’s also important to lock in our circadian rhythm with food in the morning and not overdo it at night.
Being a shift worker is not good for your health. Neither is eating like one. 
While keeping body fat levels low is important for diabetes management, eating earlier seems to improve our insulin sensitivity independent of weight loss.
We have greater insulin sensitivity in the morning. Our body is primed to use food. Food eaten later in the day is more likely to be stored for longer.
How to do it
eTRF is not always the most convenient thing.
Lots of people are not hungry in the morning, particularly if they tend to eat a large evening meal.
Left to our own devices, we tend to optimise for maximum storage to prepare for the coming winter.
Most people find it takes a week or two to get into the new groove of eating earlier.
Eating your main meal with the family at night is more social and eating in front of the TV when you’re relaxing can be fun. But if you need that extra edge to manage your weight or diabetes then moving some of your dinner calories to breakfast might just be worth the effort.
“Complete abstinence is easier than perfect moderation.”
This article is a follow up to the “How to use your glucose metre as a fuel gauge” article, which has been quite popular, with lots of people reporting success in lowering their blood glucose and recalibrating their hunger signals by using the numbers they see on their glucose metre.
To recap, the process revolves around the idea that, perhaps even better than calorie counting or carbohydrate counting, the numbers you see on your blood glucose metre are a good indication of whether you are running low on fuel and need to eat or whether you are just eating out of habit, routine, social boredom or for entertainment.
While eating for pleasure occasionally or as part of a celebration is fine and part of enjoying life, in the long run, most of us need to find a way to obtain the nutrients we need with less energy if we want to avoid obesity, diabetes and all the associated negative consequences.
If we eat highly insulinogenic low nutrient density foods regularly our insulin levels stay high and our fat stays locked in storage and hunger drives us to eat more frequently. However, if we reverse this cycle to lower our glucose and insulin to normal levels we start to eat less frequently and we allow our stored energy to flow out of our fat cells, our appetite decrease and there is a good chance we will lose weight and gain health.
The table below shows the simple process whereby someone could decide if they really need to eat. Using this process would ensure that their blood glucose levels continue to trend down as their excess energy in their bloodstream and vital organs (pancreas, liver etc) flows out of storage.
> 7-day average, well slept and low-stress
delay eating and/or exercise and wait for blood glucose to come down
if hungry, eat higher insulin load foods and delay exercise
Using numerical outputs to guide our decision making
There is no end of debate as to whether a calorie is a calorie or whether calories matter. Rather than tracking estimates of inputs like calories eaten or calories burned in exercise, there is nothing like tracking outputs such as your blood glucose levels, waist or weight to understand what your body is doing with the food you are eating and whether you are eating too much or too little.
If your glucose levels, insulin, waist or weight are increasing then chances are you’re eating too much, too often or the wrong type of food.
The plot below is a stark reminder that our chances of living longer improve if we have lower body fat levels or a waist to height ratio close to 0.5.
The problem with tracking glucose levels
The ‘problem’ with tracking blood glucose levels is that, in time, with regular fasting, our glucose levels will normalise to healthy levels but we may still be left with excess weight. So where do we turn once our blood glucose levels are optimal but our body fat levels are still above optimal?
This brings us to the star of this article, Rebecca Latham, who is a great example of how you can use your body measurements to guide your feast / fast cycle to achieve your long-term goals.
After a stressful time towards the end of 2015 Rebecca Latham decided she needed to make a focused effort to her lose some extra weight that had crept on. Rebecca is also particularly motivated by her family history of ALS, Parkinson’s Disease, dementia and cancer and her own ongoing battle with Type 2 Diabetes.
On 1 January 2016, Rebecca set an initial goal to lose 0.2 pounds per day over three months. Rebecca was also eager to reduce her fasting blood glucose levels from the 100mg/dL back to the 70mg/dL that they had been at before she regained her weight.
Part of Rebecca’s inspiration comes from her uncle, Buell Carlton Cole.
He was general surgeon to the President of the United States, who would control his weight by simply not eating until he returned to his goal weight. I initially thought this was an unhealthy approach until I read up a more about intermittent fasting.
Rather than simply not eating until she achieved her goal weight, Rebecca’s system involved not eating on days when her weight in the morning was above her target weight. Her only exception was to be special occasions and celebrations.
Here are Rebecca’s weight loss results during her initial 90-day challenge. Initial weight loss can be quite quick as the insulin levels drop and the body releases water. However, it gets a bit harder to continue with straight line weight loss as time goes on as you can see towards the end.
After the reached her initial goal, Rebecca had some issues that she needed to look after and ended up regaining some of the weight as you can see in the plot below of her weight over the past year. However, once these challenges were behind her she got back on her program. For the final part leading up to the end of the year she has dropped her goal weight loss back to 0.06lbs per day to hit her goal on 31 December 2016. See if you can spot the few ‘blips’ around Thanksgiving and Christmas.
This chart shows that she needed to fast for about one day in three through the year to lose nearly a quarter of her body weight over the year!
Reflecting on her journey, Rebecca says:
I reached my highest lifetime weight in February 2009, when I weighed in at 158 pounds, with a body fat percentage of 43.7%. This is my scale weight chart for this past almost eight years since I started eating low carb high fat (LCHF) and nutritional ketosis.
Each time I lost weight and stopped tracking and weighing myself, I gradually put most of the weight back on again. As you can see by the chart, this happened several times, and the last few times it happened, my weight was going up a little higher each time.
On January 1, 2016, I developed and started using my Protocol. Since starting the Protocol, I took two breaks, once in May 2016 when my husband had a heart attack and I was too concerned with his health to care about my own, but I got back on the Protocol within a couple of weeks and started seeing success again.
The next time I took a break was in July 2016, when I had to eat high carb and not fast for a week in preparation for some metabolic testing. As soon as the testing was over, I was back on the Protocol and started losing again. I have been going strong ever since, with small gains here and there brought on by restaurant meals and Thanksgiving.
I have now I reached my ultimate goal for scale weight, weighing in at 122.4 pounds with a body fat percentage of 25.7%, which means that I have lost approximately 37.5 pounds of body fat. The Protocol is the only thing that has brought me sustained weight loss, and I plan to follow it for the rest of my life!
Many people have a love/hate or even just a hate/hate relationship with their bathroom scale. It would be nice if low carb or nutrient dense achieved optimal health outcomes without any restriction for everyone. However, unfortunately, sustaining weight loss in the long term often takes discipline, some form of accountability and some level of restriction for most of us.
While weighing yourself every day isn’t much fun, the national weight control registry data indicates that people who have successfully lost weight and kept it off weigh themselves regularly.   Rebecca’s intended long term maintenance plan will likely be to weigh herself regularly and fast again once her weight goes outside her target range.
Better than calorie counting?
Some people who first try low carb or keto find that they initially lose a lot of weight eating to satiety as their blood glucose and insulin levels drop to healthier levels. However, in the long term, many people find that they need to be more disciplined and mindful of how much and/or how often they are eating to reach their optimal level of body composition.
The great thing about combining fasting with working to a goal like this is that it makes sure you don’t overdo the feasting days. I’ve found personally that it can be hard to know how much to eat after a fast. A quantitative system like this helps to manage and calibrate your appetite when you’re feasting.
If you eat to satiety, and not beyond, then you won’t have to fast again as soon as compared to if you binge after your fast. Eating to satiety on a regular basis means that your body’s metabolism doesn’t slow and adjust in the same way that it would if you maintained a constant caloric restriction.
Life extension benefits
There are a number of benefits to fasting:
You can reduce your insulin levels more than if eating small but regular meals which keeps your insulin levels consistently elevated.
Fasting gives your body a chance to repair through a process called autophagy which is where the old cells are cleaned up which allow space for the fresh new cells to grow.
Fasting trains your body to become ‘metabolically flexible’ so you can use your body fat stores for and your food for fuel.
There is less need to focus on the quantity of food eaten at every single meal.
It’s not ideal to always be in growth mode with mTOR switched on. Alternating periods of growth and repair appear to be more beneficial in the long term.
Fasting makes sense from an ancestral point of view when we wouldn’t have had constant access to plentiful food the way we do now. Periods of intentional restriction mimic what we have become adapted to and follow the seasons of the past.
Fasting also seems to have some special anti-aging effects. When food is scarce your body senses an emergency, and sends out sirtuin proteins to maximise the health of our mitochondria to increase the chance that you will survive the famine and have the best chance of living to a time when food is more plentiful and you can reproduce and pass on your genes. Unfortunately, this emergency repair function doesn’t happen when food is plentiful.
Fasting and blood glucose levels
During the first three months following her protocol, Rebecca added a blood glucose target to also bring her blood sugar down by 0.25 mg/dL per day. As you can see in the chart below her blood glucose levels have dropped pretty much in parallel with her weight loss during this time.
More recently, she tested her blood glucose levels and found that they were consistently great so she ended up discontinuing the testing because it was becoming monotonous and not helping her make useful decisions.
While it’s useful to track a few things, it can be overwhelming and time-consuming to keep track of too many things at once and lead to analysis paralysis. It’s good to find a handful of things to track that will help you make useful decisions.
Do we lose fat or muscle during fasting?
One hot topic of discussion is the amount of lean mass (i.e. or muscle) that one may lose in long term fasting.
The reality is that any weight loss is going to consist of a combination of water, fat and muscle (or lean muscle mass). The chart below from Kevin Hall’s model shows that we initially lose a lot of carbohydrate (glycogen) and with it a lot of water.
Protein / muscle loss is the smallest component of loss from the body and this decreases as we adapt more to using fat and ketones rather than relying on glucose. It takes a few days to adapt to using fat and ketones, but in the long run they are by far the greatest proportion of energy used during fasting.
Rebecca’s experience aligns with this. She didn’t get a DEXA scan, but she does take regular body measurements which she uses to calculate her body fat percentage (see US Navy Circumference Method). Based on these measurements she lost 28.6 lbs of fat and 3.0 lbs of lean mass. So, more than 90% of her weight loss over the past year was fat.
“Problems” with fasting
Jason Fung has recently popularised the concept of fasting in the low carb community via his blog and videos and published The Complete Guide to Fasting. There is a ton of convincing evidence on the benefits of fasting which is an age old practice for a variety of reasons.
However, Dr Steve Phinney has come out highlighting his concerns with long term fasting with respect to loss of lean tissues as well as vitamins and minerals. A number of others have expressed concerns that fasting without due care and attention to refeeding will not be beneficial in the long term.
One way to reconcile the differences is to see these concerns as two ends of the spectrum. Jason’s focus is very sick people who come to him with major kidney issues due to their advanced Type 2 Diabetes, while Steve’s focus is more around maximising athletic performance for those whom maintaining muscle mass is critical to performance.
Also, if you are more fat adapted your body will be able to more easily draw energy from stored body fat rather than requiring glucose which can be drawn from the protein in your body via gluconeogenesis.
Most people don’t fit neatly into either of the extremes, so how do you refine the approach to suit your current situation? That is where optimising your food choices to suit your current situation comes in.
How much to eat after your fast?
Personally, one challenge I find with fasting is that it’s easy to overdo it when you get to eat again. I think some people experience this more than others. Dr Phinney made the analogy that telling someone not to binge at the end of a fast is like telling someone to hold their breath but then not to take too big a breath when they come up for air.
While some people can eat normally the next day after a fast, personally I find that it’s easy to reach for the energy dense lower nutrient dense foods or to give yourself liberty to eat foods that you may not normally eat if you were being disciplined all the time. By doing this, I’ve found it’s still possible to maintain or gain weight when fasting more days that you eat if you’re not disciplined with what you eat on your feasting days.
If you find yourself reaching for energy dense low nutrient density foods like processed carbs, a block of chocolate or litre of cream after your fast then you could take that as a sign that you need to revert to shorter fasting periods until you’re more fat adapted.
Another challenge with fasting is that it will deplete your system of vital nutrients in the long term meaning that you may be more inclined to binge when you do eat unless you’ve focusing on maximising nutrient density in your feasting periods.
What to eat after you fast
One of the unique things about fasting is that it forces your body into the cleansing process of autophagy and primes the body to rebuild. Hence, it’s especially important to feed the parts of the body you want to grow (lean muscle mass is critical for long term health) and maximise the nutrient density during the initial refeed.
In some ways, a fast is only as good as the feast afterwards that your body is highly primed to absorb. For me that means trying to plan some nutrient dense greens and a solid amount of protein for my first meal so I don’t end up reaching for the energy dense cream, butter or peanut butter or indulge in some junk carbage because I feel like I’ve earned it.
If your goal is to lose fat during the fast then it’s important to build back the essential vitamins, minerals and amino acids during the feeding period. The body will fight to get what it needs in the long run and I think you’ll have a better chance of avoiding cravings and involuntary binging if you maximise the essential nutrients of your food when you do this. And if you are using fasting to achieve long term weight loss I think it makes sense to try to get the maximum number of nutrients with the least amount of energy (a.k.a. avoiding empty calories and maximising nutrient density).
People looking to use fasting for long term weight loss may benefit from starting out with a higher fat dietary approach if they are very insulin resistant. However, as blood glucose levels progressively improve you should be able to transition to a more nutrient dense nutritional approach which will allow you to get your required nutrients with less energy.
I see a lot of arguments online regarding whether high fat keto or high protein is optimal. I think these arguments come down to context. The table below gives some guidance as to which approach might be right for you initially based on:
your blood glucose levels (if your glucose levels are high you will likely benefit from a higher fat keto approach, at least initially until your glucose levels start to normalise),
ketones (some is better than none, but there’s no need to chase high ketones with heaps of extra dietary fat, especially if you are trying to lose body fat), and
waist to height ratio (this is going to be more useful than the BMI chart to tell you if you still need to lose a bit of weight).
This graphic from Dr Ted Naiman demonstrates how foods are all somewhere on the sliding scale between maximum energy density and maximum nutrient density. If we are aiming for long term weight loss, we want to maximise nutrient density as much as we can while keeping blood glucose levels and insulin levels low. Then as we improve blood glucose levels and insulin sensitivity we will be able continue to move towards the right to more nutrient dense approaches which will help to provide satiety and adequate nutrition with less energy.
If / when we reach our ideal weight or level of body fat, we can afford to add back in some more energy dense foods because we are no longer trying to use the glucose in our liver (glycogen) and body fat from our belly. 
I originally started eating ketogenically a few years ago by eating very high fat, lower protein, and very low (sometimes zero) carbs. That worked for a while, and I lost weight, but as time went on, I found that I was eating so much fat and so little protein that I was getting hungry all the time.
I now get plenty of protein on my eating days. I am 5’3″ and eat 125g on the days that I feast. I find with this approach I am less hungry and my Protocol requires me to fast less often.
Losing lean muscle mass is bad news whether you’re a bodybuilder, a diabetic or an older person battling sarcopenia. Not only will losing muscle decrease your metabolic health, glucose disposal and metabolic rate, your body will also increase appetite to regain the muscle, making it harder to keep on losing the fat.
It’s not just about looking buff and building muscles, amino acids are critical to fueling mitochondrial function and creating neurotransmitters that assist in staying happy and sleeping well. For example, the amino acid tryptophan produces serotonin which makes us happy and melatonin which helps us sleep.
For reference, Rebecca’s 125g of protein per day ends up being 3g/kg LMB. This equates to 2g/kg LBM per day on average if you factor in the fact that she fasts every third day. This aligns with Volek and Phinney’s recommendations in the Art and Science of Low Carb Living (i.e. 1.5 – 2g/kg reference body weight) which equates to 1.7 to 2.2g/kg LBM . In Lyle McDondald’s Rapid Fat Loss Handbook he recommends between 1.8 to 4.4g/kg LBM protein, with a higher level of protein if you are lean and more active, and less if you are obese and inactive, to prevent muscle loss during a protein sparing modified fast.
The optimal food lists have been designed to help maximise nutrient density (including ensuring adequate amino acids) ideally without needing to rely on tracking calories. Rebecca does track what she eats, but mainly to make sure she is getting adequate protein on her feasting days.
The Protocol does not *require* tracking food intake, but I strongly recommend it. I found, for myself, that if I did not track on feast days, I ate too much fat and not enough protein, and I was having to fast a lot more to make my daily goals. Starting in April, I did start using the OKL macros and recommending the same to others.
Rebecca also practices early time restricted feeding (eTRF) which means she eats earlier in the day due to better insulin sensitivity which seems to be producing good results for a lot of people. I have heard a lot of reports from people that have found that eating earlier rather than later helps with sleep, appetite and blood sugar.
I encourage you to check out Rebecca’s Facebook group where she has documented her daily progress and learnings and supports others using the Protocol. You can download a spreadsheet and start tracking and sharing your own progress. Public accountability and a supportive community are always going to be helpful in achieving such a long-term goal.
Rebecca has ‘stacked’ several different techniques from her learnings to ensure her long term success this time around to fight her genetics and tendency to regain her weight.
Before launching in, there are several considerations to tailor Rebecca’s approach to suit your situation and goals such as:
Target rate of weight loss. Rebecca recommends that people aim for a maximum weight loss of 0.2lbs or 0.1kg per day. Anything more is typically hard to sustain in the long term. You might be feeling ambitious and this level might be easy to achieve when things are going well but it may be hard to sustain in the longer term, especially if you have a few social gatherings or parties that leave you with some catching up to do. As you approach your goal weight you may be glad you chose a less aggressive goal as the weight loss becomes a little harder to achieve.
Social context. This type of approach can be hard to work around family or social commitments. I like to enjoy good food with my family on the weekends and save my fasting for work days when it’s easier to skip food. When I’ve followed this protocol, it leaves me fasting Monday and Tuesday and eating dinner Tuesday night with the family or ideally a hearty breakfast Wednesday morning. Based on my scale weight I may end up fasting another day or two on Thursday and / or Friday.
What’s your maximum fasting tolerance? Fasting gets easier with practice. You might want to start with just skipping a couple of meals, then going for 36 hours, then a couple of days. If you find your cravings are leading you to binge or sacrifice food quality, then you may want to stick with shorter fasting periods or aim for a less aggressive target rate of weight loss.
What else do you want to measure? The good thing about measuring weight is that it’s easy. It can however be problematic in that there are a ton of things that influence your weight other than fat gain or loss (e.g. muscle, water, how full is your gut, when did you go to the toilet etc); it’s an easy way to measure your progress day to day. In the long term, you want to see a trend in the right direction. If you have diabetes, then you may also want to track your glucose and even your ketone levels. It will also be useful to track your waist measurement periodically to see whether you’re getting closer to your optimum waist to height ratio of 0.5, particularly if you are building muscle and hence the BMI chart categories won’t mean much for you. For reference, during 2016 Rebecca’s waist to height ratio went from 0.54 to 0.44.
How full is your stress bucket?
A word of warning, again from personal experience, is that this approach is simple, but it’s not necessarily easy. Wondering what number you will see on the scale each day can be exciting but a bit stressful. It can be frustrating when you see the number going in the wrong direction or not keeping up with your target rate of weight loss.
A regular fasting routine is another thing that you will add to your “stress bucket” and if you don’t already have your sleep, nutrition, relationships, stress, circadian rhythm and regular activity in check then the cortisol and related insulin spikes may make achieving long term success with this approach harder than it would otherwise be.
If you do have these things ticked off and you’re feeling relaxed after a Christmas holidays but may have overdone the celebratory food then you can download a copy of the spreadsheet from My Low Carb Road – Fasting Support and give it a go.
Then in 2013, Jason Fung emerged onto the low carb scene with his epic six part Aetiology of Obesity YouTube Series in which he detailed a wide range of theories relating to obesity and diabetes.
Essentially, Jason’s key points are that:
simply treating Type 2 diabetes with more insulin to suppress blood glucose levels while continuing to eat the diet that caused the diabetes is futile,
people with Type 2 diabetes are already secreting plenty of insulin, and
insulin resistance is the real problem that needs to be addressed.
Jason’s Intensive Dietary Management blog has explored a lot of concepts that made their way into his March 2016 book, The Obesity Code. However surprisingly, given that Jason is the fasting guy, the book didn’t talk much about fasting.
my experience with fasting
I have benefited personally from implementing an intermittent fasting routine after getting my head around Jason’s work. I like the way I look and perform, both mentally and physically, after a few days of not eating. I also like the way my belt feels looser and my clothes fit better.
Complete abstinence is easier than perfect moderation.
I recently did a seven day fast and since then I’ve done a series of four day fasts, testing my glucose and blood and breath ketones with a range of different supplements (e.g. alkaline mineral mix, exogenous ketones, bulletproof coffee/fat fast and Nicotinamide Riboside) to see if they made any difference to how I feel and perform, both mentally and physically.
Fasting does become easier with practice as your body gets used to accessing fat for fuel.
I love the mental clarity! My workout performance and capacity even seem to be better when I’ve fasted for a few days.
My key fasting takeaways are:
Fasting is not that hard. Give it a try.
You can build up slowly.
If you don’t feel good. Eat!
The more I learn about health and nutrition, the more I realise how critical it is to be able to burn fat and conserve glucose for occasional use. We get into all sorts of trouble when we get stuck burning glucose.
Our body is like a hybrid car with a slow burning fat motor (with a big fuel tank) and high octane glucose motor (with a small fuel tank). If you’re always filling the small high octane fuel tank to overflowing, you’ll always be stuck burning glucose and your fat burning engine will start to seize up (i.e. insulin resistance and diabetes).
Reducing the processed carbs in our diet enables us to lower our insulin levels and retrain our body to burn fat again. But nothing lowers insulin as aggressively and effectively as not eating.
Even though lots of Jason’s thoughts on fasting seem self-evident, his blog elucidating them has been very popular, perhaps because the concept of fasting is novel in the context of our current nutritional education.
We’ve been trained, or at least given permission, to eat as often as we want by the people that are selling food or sponsored by them.
Jason’s angle on obesity and diabetes comes from his background as a nephrologist (kidney specialist) who deals with chronically ill people who are a long way down the wrong track before they come to his office. Jason also talks about how he had tried to educate his patients about reducing their carbs, however, after eating the same thing for 70 years, this is just too hard for many people to change.
Desperate times call for desperate measures!
Many of these patients come to him jamming in hundreds of units a day of insulin to suppress blood glucose levels, even though their own pancreas is still likely secreting more than enough insulin.
Rather than continuing to hammer more insulin to suppress the symptom (high blood glucose), the solution, according to Jason, is to attack the ultimate cause (insulin resistance) directly.
Jimmy Moore is well known to most people that have an interest in low carb or ketogenic diets. Whether you agree with his approach, it’s safe to say that low carb and keto would not be as popular today without his role.
Meanwhile, Jason talks about trying to educate people about reducing the processed carbs from their diet not working, not because of the science but more due to people not being able to change their eating habits after 70 years.
the Complete Guide to Fasting
You’ve probably heard by now that Jason has teamed up with Jimmy to write The CompleteGuide to Fasting which captures Jason’s extensive thoughts on fasting from the blog along with Jimmy’s n=1 experiences and wraps them up in a cohesive comprehensive manual with a colourful bow.
Similar to The Obesity Code, TCGTF is a compilation of ideas that Jason has developed on his Intensive Dietary Management blog. Blogging is a great way to get the ideas together and thrash them out in a public forum. Some people love to read the latest blog posts and debate the minutiae, however, most people would rather spend the $9 and sit down with a comprehensive book and get the full story.
Unlike The Obesity Code, TCGTF is a bright, ffull-colourproduction with great graphics that will make it worth buying the hard copy to have and to hold.
TCGTF did originally have the working title Fasting Clarity as a follow on from Jimmy’s previous Cholesterol Clarity and Keto Clarity. However, other than Jimmy’s discussion of his n=1 fasting experiences, TCGTF is predominantly written in Jason’s voice building from his blog, so it wouldn’t be appropriate for it to have become the third in Jimmy’s Clarity series.
What is similar to Jimmy’s clarity series is that it’s easy to read and accessible for people who are looking for an entry level resource. This book will be great for people who are interested in the idea of fasting. It is indeed the complete guide to fasting and is full of references to studies, however, it doesn’t go into so much depth as to lose the average reader with scientific detail and jargon.
The book covers:
Jimmy’s n=1 experience with fasting,
Dr George Cahill’s seminal work on the effects of fasting on metabolism, glucose, ghrelin, insulin, and electrolytes,
the history of fasting over the centuries,
myth busting about fasting,
fasting in weight loss,
fasting and diabetes, physical health, and mental clarity,
managing hunger during a fast,
when not to fast, and
when fasting can go wrong.
The book is complete with a section on fasting fluids (water, coffee, tea, broth) and a range of different protocols that you can use depending on what suits you. What did seem out of place are the recipes for proper meals. Apparently, the publisher insisted they include these to widen the appeal (If you don’t like the fasting bit you’ve still got some new recipes?)
Overall, the book will be an obvious addition to the library (or Kindle) of people who are already fans of Jason and / or Jimmy and want a polished, consolidated presentation of all their previous work with a bunch of new material added.
TCGTF will also be a great read for someone who is interested learning more about fasting and wants to start at the beginning. TCGTF is the most comprehensive book on the topic of fasting that I’m aware of.
my additional 2c…
Jason doesn’t mind weighing into a controversial argument, using some hyperbole or dropping the occasional F-bomb for effect and Jimmy’s no stranger to controversy either, so I thought I’d take this opportunity to give you my 2c on some of the topical issues at the fringe that aren’t specifically unpacked in the book. We learn more as we thrash out the controversial issues at the fringes. Many arguments come down to context.
target glucose levels
Jason has come under attack for using the word ‘cured’ in relation to HbAc1 values that most diabetes associations would consider non-diabetic, though are not yet optimal.
In the book Jason does discuss relaxing target blood glucose levels during fasting. This makes sense for someone taking a slew of diabetic medications. They’re probably not going to continue the journey if they end up in a hypoglycaemic coma on day one.
The chart below shows the real life blood glucose variability for someone with Type 1 Diabetes on a standard diet. With such massive fluctuations in glucose levels, it’s impossible to target ideal blood glucose levels (e.g. Dr Bernstein’s magic target blood glucose number of 4.6 mmol/L or 83 mg/dL).
If your glucose levels are swinging wildly due to a poor diet coupled with lots of medication, your glucose levels are simply going to tank when you stop eating. Hence, a safe approach is to back off the medication, at least initially, until your glucose levels have normalized.
Being married to someone with Type 1 Diabetes, I have learned the practical realities of getting blood glucose levels as low as possible while still avoiding dangerous lows. My wife Monica doesn’t feel well when her blood glucose levels are too low, but neither does she feel good with high blood glucose levels. Balancing insulin and food to get blood glucose levels as low as possible without experiencing lows requires constant monitoring.
The chart below shows how scattered blood glucose levels can be even if you’re fairly well controlled. Ideally you want the average blood glucose level to be as low as possible while minimising the number of hypoglycaemic episodes (i.e. below the red line). If you can’t reduce the variability you just can’t bring the average blood glucose level down. The last thing you want is to be eating to raise your blood glucose levels because you had too much blood glucose lowering medication.
Pretty much everyone agrees that it’s dumb to be eating crap food and dosing with industrial levels of insulin to manage blood glucose levels. High levels of exogenous insulin just drive the sugar that is not being used to be stored as fat in your belly, then your organs, and then in the more fragile places like your eyes and the brain.
Jason’s perspective is that people who are chronically insulin resistant and morbidly obese are likely producing more than enough insulin. The last thing they need is exogenous insulin which will keep the fat locked up in their belly and vital organs. Dropping insulin levels as low as possible using a low insulin load diet and fasting coupled with reducing medications will let the fat flow out.
fasting to optimise blood glucose levels
In the long run, neither high insulin nor high glucose levels are optimal.
Once you’ve broken the back of your insulin resistance with fasting, you can continue to drive your blood glucose levels down towards optimal levels.
One of the most popular articles on the Optimising Nutrition blog is how to use your glucose meter as a fuel gauge which details how you can time your fasting based on your blood glucose levels to ensure they continue to reduce.
Your blood glucose levels can help calibrate your hunger and help you to understand if you really need to eat. I think this is a great approach for people whose main issue is high blood glucose levels and who aren’t ready to launch into longer multi day fasts.
In a similar way, a disciplined fasting routine can help optimise blood glucose levels in the long term. The chart below shows a plot of Rebecca Latham’s blood glucose levels over three months where she used her fasting blood glucose numbers AND body weight to decide if she would eat on any given day.
While there is some scatter in the blood glucose levels, you can see that regular fasting does help to reduce blood glucose levels over the long term.
Once you’ve lost your weight , broken the back of your insulin resistance and stopped eating crap food, you may find that you still need some exogenous insulin or other diabetic medication to optimise blood glucose levels if you have burned out your pancreas.
The TGTF book covers off on several fasting regimens such as intermittent fasting, 24 hours, 36 hours, 42 hours and 7 to 14 days. One concept that I’m intrigued by, similar to the idea of using your glucose meter as a fuel gauge, is using your bathroom scale as a fuel gauge.
The reality, at least in my experience, is that we can overcompensate for our fasting during our feasting and end up not moving forward toward our goal.
If your goal is to lose weight I like the idea of tracking your weight and not eating on days that your weight is above your goal weight for that day.
Again, Rebecca Latham has done a great job building an online community around the concept of using weight as a signal to fast through her Facebook group My Low Carb Road – Fasting Support.
The chart below shows Rebecca’s weight loss journey through 2016 where she initially targeted a weight loss of 0.2 pounds AND a reduction of 0.25 mg/dL in blood glucose per day. After three months, she stabilized for a period (during a period when she had a number of major family issues to look after). She is now using a less aggressive weight loss goal as she heads for her long-term target weight at the end of the year.
The chart below shows the fasting frequency required to achieve her goals during 2016. Tracking her weight against her target rate of weight loss has required her to fast a little more than one day in three to stay on track.
Eating quality food is part of the battle, but managing how often you eat is also an important consideration. After you’ve fasted for a few days, you can easily excuse yourself for eating more when you feast again. And maybe it’s OK to enjoy your food when you do eat rather than tracking every calorie and trying to consciously limit them.
The obvious caveat is that there are a lot of other things that influence your scale weight such as muscle gain, water, GI tract contents etc, but this is another way to keep yourself accountable over the long term.
FAST WELL, FEED WELL
Fasting is a key component of the metabolic healing process, but it’s only one part of the story.
Fasting is like ripping out your kitchen to put in a new one. You have to demolish and remove the old stovetop to put the new shiny one back in. You don’t sticky tape the new marble bench top over the crappy old Laminex. You have to clean out the old junk before you implement the new, latest, and greatest model.
In fasting, the demolition process is called autophagy, where the body ‘self eats’ the old proteins and aging body parts. The great thing about minimising all food intake is that you get a deeper cleanse than other options such as fat fast, 500 calories per day or a protein sparing modified fast (PSMF).
But keep in mind that it’s the feast after the fast that builds up the shiny, new body parts that will help you live a longer, healthier, and happier life.
“Fasting without proper refeeding is called anorexia.”
Even fasting guru Valter Longo is now talking about the importance of feast / fast cycles rather than chronic restriction. In the end you need to find the right balance of feasting / fasting, insulin / glucagon, mTOR / AMPK that is right for you.
In TCGTF, Jason and Jimmy talk about prioritising nutrient dense, natural, unprocessed, low carb, moderate protein foods after the fast. I’d like to reiterate that principle and emphasise that nutrient density becomes even more important if you are fasting regularly or for longer periods.
In the long term, I think your body will drive you to seek out more food if you’re not giving it the nutrients it needs to thrive. Conversely, I think if you are providing your body with the nutrients it needs with the minimum of calories I think you will have a better chance of accessing your own body fat and reaching your fat loss goals.
optimising insulin levels AND nutrient density
It’s been great to see the concept of the food insulin index and insulin load being used by so many people! In theory, when people reduce the insulin load of their diet they more easily access their own body fat and thus normalizes appetite.
Some people who are very insulin resistant do well, at least initially, on a very high fat diet. However, as glycogen levels are depleted and blood glucose levels start to normalise, I think it is prudent to transition to the most nutrient dense foods possible while still maintaining good (though maybe not yet optimal) blood glucose levels.
The problem with doubling down on reducing insulin by fasting combined with eating only ultra-low insulinogenic foods is that you end up “refeeding” with refined fat after your fast.
While lowering carbs and improving food quality is the first step, I think that, as soon as possible you should start focusing on building up your metabolic machinery (i.e. muscles and mitochondria). A low carb nutrient dense diet is part of the story, but I don’t see many people with amazing insulin sensitivity that don’t also have a good amount of lean muscle mass which is critical to ‘glucose disposal’, good blood sugar levels and metabolic health.
This recent IHMC video from Doug McGuff provides a stark reminder of why we should all be focusing on maximising strength and lean muscle mass to slow aging.
The chart below shows a comparison of the nutrient density of the various dietary approaches. Unfortunately, a super high fat diet is not necessarily going to be as nutrient dense and thus support muscle growth, weight loss, or optimal mitochondrial function as well as other options.
The chart below (click to enlarge) shows a comparison of the various essential nutrients provided by a high fat therapeutic ketogenic dietary approach versus a nutrient dense approach that would suit someone who is insulin sensitive.
I developed a range of lists of optimal foods that will help people in different situations with different goals to maximise the nutrient density that should be delivered in the feast after the fast. The table below contains links to separate blog posts and printable .pdfs. The table is sorted from highest to lowest nutrient density. In time, you may be able to progress to a more nutrient dense set of foods as your insulin resistance improves.
Jason had a “robust discussion” with Steve Phinney over the topic of ideal protein levels recently during the Q&A session at the recent Low Carb Vail Conference.
To give some context again, Phinney is used to dealing with athletes who require optimal performance and are looking to optimise strength. Meanwhile Jason’s patient population is typically morbidly obese people who are on kidney dialysis and probably have some excess protein, as well as a lot of fat that they could donate to the cause of losing weight.
I also know that Jimmy is a fan of Ron Rosedale’s approach of minimising protein to minimise stimulation of mTOR. Jimmy and Ron are currently working on another book (mTOR Clarity?). Protein also stimulates mTOR which regulates growth which is great when you’re young but perhaps is not so great when you’ve grown more than enough.
The typical concern that people have with protein in a ketogenic context is that it raises blood insulin in people who are insulin resistant. ‘Excess protein’ can be converted to blood glucose via gluconeogenesis in people who are insulin resistant and can’t metabolise fat very well.
Managing insulin dosing for someone with Type 1 Diabetes like my wife Monica is a real issue, though she doesn’t actively avoid protein. She just needs to dose with adequate insulin for the protein being eaten to manage the glucose rise.
The chart below shows the difference in glucose and insulin response to protein in people who have Type 2 Diabetes (yellow lines) versus insulin sensitive (white lines) showing that someone who is insulin resistant will need more insulin to deal with the protein.
As well as insulin resistance, these people are also “anabolic resistant” meaning that some of the protein that they eat is turned into glucose rather than muscle leaving them with muscles that are wasting away.
People who are insulin resistant are leaching protein into their bloodstream as glucose because they can’t mobilise their fat stores for fuel. They are dependent on glucose and they’ll even catabolise their own muscle to get the glucose they need if they stop eating glucose.
While it’s nice to minimise insulin levels, I wonder whether people who are in this situation may actually need more protein to make up for the protein that is being lost by the conversion to glucose to enable them to maintain lean muscle mass. Perhaps it’s actually the people who are insulin sensitive that can get away with lower levels of protein?
As well as improving diet quality which will reduce insulin and thus improve insulin resistance, in the long term it’s also very important to maintain and build muscle to be able to dispose of glucose efficiently and also improve insulin resistance.
In TCGTF Jason talks about the fact that the rate of the use of protein for fuel is reduced during a fast and someone becomes more insulin sensitive. He goes to great lengths to point out that concern over muscle loss shouldn’t stop you trying out fasting (which is a valid point).
A big part of the magic of fasting is that you clean out some of your oldest and dodgiest proteins in your body and set the stage for rebuilding back new high quality parts. But the reality is that you will lose some protein from your body during a fast (though this is not altogether a bad thing).
Bodybuilders often talk about the “anabolic window” after a workout where they can maximise muscle growth after a workout. Similarly, one of the awesome things about fasting is that you reduce your insulin resistance and anabolic resistance meaning that when at the end of your fast your body is primed to allocate the high quality nutrients you eat in the right place (i.e. your muscles not your belly or blood stream).
In the end, I think optimal protein intake has to be guided to some extent by appetite. You’ll want more if you need it, and less if you don’t.
I think if we focus on eating from a shortlist of nutrient dense unprocessed foods we won’t have to worry too much about whether we should be eating 0.8 or 2.2 g/kg of lean body mass.
However, avoiding nutrient dense, protein-containing foods and instead “feasting” on processed fat when you break your fast will be counter-productive if your goal is weight loss and waste a golden opportunity to build new muscle.
are you really insulin resistant?
Insulin resistance and obesity is a continuum.
Not everyone who is obese is necessarily insulin resistant.
If you are really insulin resistant, then fasting, reducing carbs, and maybe increasing the fat content of your diet will enable you to improve your insulin resistance. This will then help with appetite regulation because your ketones will kick in when your blood glucose levels drop.
However, if you continue to overdo your energy intake (e.g. by chasing high ketones with a super high fat, low protein diet), then chances are, just like your body is primed to store protein as muscle, you will be very effective at storing that dietary fat as body fat.
I fear there are a lot of people who are obese but actually insulin sensitive who are pursuing a therapeutic ketogenic dietary approach in the belief that it will lead to weight loss. If you’re not sure which approach is right for you and whether you are insulin resistant, this survey may help you identify your optimal dietary approach.
optimal ketone levels
Measuring ketones is really fascinating but confusing as well.
Urine ketones strips have limited use and will disappear as you start to actually use the ketones for energy.
In a similar way blood ketones can be fleeting. Some is better than none, but more is not necessarily better. As shown in the chart of my seven day fast below I have had amazing ketones and felt really buzzed at that point but since then I haven’t been able to repeat this. I think sometimes as your body adapts to burning fat for fuel the ketones may be really high but then as it becomes efficient it will stabilise and run at lower ketone levels even when fasting.
If your ketone levels are high when fasting then that’s great. Keep it up. They might stay high. They might decrease. But don’t chase super high ketones in the fed state unless you are about to race the Tour de France or if you want your body to pump out some extra insulin to bring them back down and store them as fat.
The chart below shows the sum of 1200 data points of ketones and blood glucose levels from about 30 people living a ketogenic lifestyle. Some of the time they have really high blood ketone levels but I think the real magic of fasting happens when the energy in our bloodstream decreases and we force our body to rely on our own body fat stores.
the root cause of insulin resistance is…
So we’ve worked out that large amounts of processed carbs drive high blood glucose and insulin levels which is bad.
We’ve also worked out that insulin resistance drives insulin levels higher, which is bad.
But what is the root cause of insulin resistance?
I think Jason has touched on a key component in that, as with many things, resistance is caused by excess. If we can normalise insulin levels, then our sensitivity to insulin will return, similar to our exposure to caffeine or alcohol.
However, at the same time, I think insulin resistance is potentially more fundamentally caused by our sluggish mitochondria that don’t have enough capacity (number or strength) to process the energy we are throwing at them, regardless of whether they come from protein, carbs, or fat.
A low carb diet lowers the bar to enable us to normalise our blood glucose levels. However, the other end of the spectrum is focusing on training our body and our mitochondria to be able to jump higher. In the long term this is achieved through, among other things, maximising nutrient dense foods and building lean body mass through resistance exercise.
The Complete Guide to Fasting is, as per the title, the complete guide to fasting. It’s the most comprehensive guide to the nuances of fasting out there and there’s a good balance between the technical detail, while still being accessible for the general public.
Fasting can help optimise blood glucose and weight in the long term, with a disciplined regimen.
Fasting makes the body more insulin sensitive and primes it for growth. When you feast after you fast, it is ideal to make sure you maximise nutrient density of the food you eat as much as possible while maintaining reasonable blood glucose levels.
Understanding your current degree of insulin resistance can help you decide which nutritional approach is right for you. As you implement a fasting routine and transition from insulin resistance to insulin sensitivity you will likely benefit from transitioning from a low insulin load approach to a more nutrient dense approach.
Some people produce more ketones than others. Some people have higher blood glucose levels.
What our ketone and glucose values tell us about our metabolic health
Hyperinsulinemia has been called as the “unifying theory of chronic disease”     . It’s beneficial to understand where you stand on the spectrum of metabolic health and insulin sensitivity.
The chart below shows the typical relationship between blood glucose and blood ketone for a range of different degrees of insulin resistance/sensitivity.
If your blood glucose levels are consistently high it’s likely you are not metabolising carbohydrate well. When you go without food, endogenous ketones are slow to kick in because your insulin levels are also high. You feel tired and hungry, and you are likely to eat again sooner and not stop until you feel good.
By contrast, if you are insulin sensitive you may be able to go longer between meals naturally and you will not feel as compelled to eat as much or as often. If someone is insulin resistant, a lower insulin load dietary approach will help with satiety and carb cravings while keeping blood glucose levels and insulin under control.
hyperinsulinemia and metabolic disorders
Exciting research is coming out underway looking at the use of EXOGENOUS ketones as an adjunct treatment for cancer or to provide energy directly to the mitochondria for people with epilepsy, dementia, Alzheimer’s and the like.
EXOGENOUS ketones may help to relieve the debilitating symptoms and side effects of acute hyperinsulinemia, Alzheimer’s, dementia, epilepsy or other conditions where glucose is not used well.
exogenous ketones and the low carb flu
Patrick Arnold, who worked with Dr Dominic D’Agostino to develop the first ketone esters and ketone salts, has noted that exogenous ketones may help alleviate the symptoms of the ‘keto flu’ during the transition from a high carb to a low carb dietary approach.
However, once you have successfully transitioned to a lower carb eating style it may be wise to reduce or eliminate the exogenous ketones to enable your body to fully up-regulate lipolysis (fat burning), maximise ENDOGENOUS ketone production and access your body fat stores.
As discussed in the article Are ketones insulinogenic and does it matter? it exogenous ketones require about half as much insulin as carbohydrate to metabolise (or about the same amount as protein). Hence the continual use of exogenous ketones will limit how much our insulin levels are able to decrease.
Someone with diabetes who follows with a nutrient dense low insulin load dietary approach may be able to successfully normalise their blood glucose and insulin levels. When this happens, your liver will be able to more easily produce ENDOGENOUS ketones which will help improve satiety between meals and decrease appetite which will, in turn, lead to weight loss.
Exercising to train your body to do more with less is also helpful.
my experience with exogenous ketones
The light blue “mild insulin resistance” line is based on my ketone and glucose tests when I started trying to wrap my head around low carb/keto.
I enthusiastically started adding generous amounts of fat from all the yummy stuff (cheese, butter, cream, peanut butter, BPC etc) in the hope of achieving higher ketone levels and therefore weight loss, but I just got fatter and more inflamed as you can see in the photo on the left.
My blood tests suggested I was developing fatty liver in my mid-30s! And I thought I was doing it right with lots of bacon and BPC?!?!?
Part of the reasons shelling out the money for the exogenous ketones was to see if it would provide a fuel source that didn’t need insulin for my wife Monica who has Type 1 Diabetes.
This metabolic jet fuel is definitely fascinating stuff! My experience is that it gave me a buzz like a BPC but also has an acute diuretic effect.
I had hoped it would have a weight loss effect like some people seemed to be saying it would.
I did find it had an amazing impact on my appetite. While it was in my system I didn’t care as much about food. However, once the ketones were used up my appetite came flooding back.
Unfortunately, my hunger and subsequent binge eating seemed to more than offset the short term appetite suppression that had occurred while the exogenous ketones were in my system. And it was not going to be financially viable for me to maintain a constant level of artificially elevated ketone levels which return to normal levels after a couple of hours.
do exogenous ketones help with weight loss?
I asked around to see if anyone had come across studies demonstrating long term weight loss effects of exogenous ketones.It was a VERY enlightening discussion if you want to check it out here.
The Pruvit FAQ says that one of the benefits of Keto//OS is weight loss. However, no reference to the research studies was provided to prove his claim.
Also, the studies that were referenced in the Pruvit FAQ all appeared to relate to the benefits of ENDOGENOUS or nutritional ketosis rather than EXOGENOUS ketone supplementation.
According to Dominic D’Agostino in a Pruvit teleseminar, the EXOGENOUS ketone salts were not designed to be a weight loss product and hence have not been studied for weight loss after all!
The only studies that we could find that mentioned EXOGENOUS ketone supplementation and weight loss were on rats and they found that there was no long term effect on weight loss.
So in spite of my hopeful $250 outlay, it seems that exogenous ketones ARE just a fuel source after all.
Even the experts don’t seem to think exogenous ketones help with fat loss.
The “metabolically healthy” line in the chart above is based on RD Dikeman’s ketone and glucose data when he fasted for 21 days.
Due to his hard-earned metabolic health and improved insulin resistance RD has developed the ability to fairly easily release ketones when he doesn’t eat for a while. RD still doesn’t find going without food effortless, but it is easier than when his insulin levels were much higher which prevented his body from accessing his body fat stores.
Through a disciplined diet and exercise habits RD has achieved a spectacular HbA1c of 4.4%.
Perhaps a two or three day water only fast testing blood glucose and ketones with no exercise would be a useful test of your insulin status? You could use RD’s glucose : ketone gradient as the gold standard.
RD also told me that when he is not fasting and is eating his regular nutrient dense higher protein meals his ketone levels are not particularly high. While RD fairly easily produces ketones when fasting, it seems they are also quickly metabolised so they do not build up in his bloodstream.
Where this gets even more interesting is when we look at the glucose and ketone data in terms of TOTAL ENERGY. That is, the energy coming from both glucose and ketones.
The average TOTAL ENERGY of the three thousand data points from these healthy people working hard to achieve nutritional ketosis is around 6.0mmol/L. It seems the body works to maintain homoeostasis around this level.
When the TOTAL ENERGY in our bloodstream increases outside of the normal range it the body raises insulin to store the excess energy. That is, unless you have untreated type 1 diabetes, in which case you end up in diabetic ketoacidosis with high blood glucose and high ketones due to the lack of insulin available to keep your energy in storage.
Regardless of whether your energy takes the form of glucose, ketones or free fatty acids, they all contribute to acetyl-coA which is oxidised to produce energy. Forcing excess unused energy to build up in the bloodstream is typically desirable and can lead to long term issues (e.g. glycation, oxidised LDL etc).
I’m not sure if ketones can be converted to glucose or body fat, but it makes sense that excess glucose would be converted to body fat via de novo lipogenesis to decrease the TOTAL ENERGY in the blood stream to normal levels.
Ketone bodies have effects on insulin and glucagon secretions that potentially contribute to the control of the rate of their own formation because of antilipolytic and lipolytic hormones, respectively. Ketones also have a direct inhibitory effect on lipolysis in adipose tissue.
Looking at the glucose and ketones together in terms of TOTAL ENERGY was a bit of an ‘ah ha’ moment for me. It helped me to understand why people like Thomas Seyfried and Dominic D’Agostino always talk about the therapeutic benefits and the insulin lowering effects of a calorie restricted ketogenic diet. 
Dealing with high ketones and high glucose is typically not a concern because it doesn’t happen in nature or when eating whole foods. But now we have refined grains, HFCS, processed fats and exogenous ketones to ‘bio hack’ our metabolism and send it into overdrive.
While fat doesn’t normally trigger an insulin response, it seems that excess unused energy, regardless of the source, will trigger an increase in insulin to reduce the TOTAL ENERGY in the blood stream.
I am concerned that if people continue to enthusiastically zealously focus on pursuing higher blood ketones “through whatever means you can” in an effort to amplify fat loss they will promote excess energy in the bloodstream which will lead to insulin resistance and hyperinsulinemia.
Using multi-level marketing tactics to distribute therapeutic supplements to the uneducated masses who are desperate to lose weight with a ‘more is better’ approach also troubles me deeply.
My heart sank when I saw this video.
MORE investigation required?
There are anecdotal reports that exogenous ketones provide mental clarity, enhanced focus and athletic performance benefits. At the same time, there are also people who have been taking these products for a while that don’t appear to be doing so well.
Recently, ketone body supplements (ketone salts and esters) have emerged and may be used to rapidly increase ketone body availability, without the need to first adapt to a ketogenic diet. However, the extent to which ketone bodies regulate skeletal muscle bioenergetics and substrate metabolism during prolonged endurance-type exercise of varying intensity and duration remains unknown. Therefore, at present there are no data available to suggest that ingestion of ketone bodies during exercise improves athletes’ performance under conditions where evidence-based nutritional strategies are applied appropriately.
Ketosis decreased muscle glycolysis and plasma lactate concentrations, while providing an alternative substrate for oxidative phosphorylation. Ketosis increased intramuscular triacylglycerol oxidation during exercise, even in the presence of normal muscle glycogen, co-ingested carbohydrate and elevated insulin. These findings may hold clues to greater human potential and a better understanding of fuel metabolism in health and disease.
I can understand how exogenous ketones could be beneficial for someone who is metabolically healthy and consuming a disciplined hypo-caloric nutrient dense diet. They would likely be able to auto regulate their appetite to easily offset the energy from the EXOGENOUS ketones with less food intake.
While it seems that EXOGENOUS ketones assist in relieving the symptoms of metabolic disorders I’m yet to be convinced that a someone who is obese and / or has Type 2 Diabetes would do as well in the long term, especially if they were hammering both more fat and exogenous ketones (along with maybe some sneaky processed carbs on the side) in an effort to get their blood ketones as higher in the hope of losing body fat.
Some questions that I couldn’t find addressed in the Pruvit FAQ that I think would be interesting to answer through a controlled study in the future are:
What is the safe dose limit of EXOGENOUS ketones for a young child? How would you adjust their maximum intake based on age and weight?
IF EXOGENOUS ketones do have a long term weight loss effect what is the upper limit of intake of EXOGENOUS ketones to avoid stunting a child’s growth?
Is there a difference in the way EXOGENOUS ketones are processed in someone is metabolically healthy versus someone who is very insulin resistant?
Does the effect on appetite continue beyond the point that the ketones are out of your system?
Do you need to take EXOGENOUS ketones continuously to maintain appetite suppression? Does the effect of ENDOGENOUS wear off as your own ENDOGENOUS ketone production down regulates? Do you need to keep taking more and more EXOGENOUS ketones to maintain healthy appetite control?
How should someone with Type 2 Diabetes adjust their medication and insulin dose based on their dose of EXOGENOUS ketones? Should they be under medical supervision during this period?
Is there a difference in health outcome if you are taking EXOGENOUS ketones in the context of a hypocaloric ketogenic diet versus a hypercaloric ketogenic diet? What about a diet high in processed carbs?
Is there a minimum effective dose to achieve optimal long term benefits to your metabolic health or is MORE better?
Are the long term health benefits of EXOGENOUS ketones equivalent to a calorie restricted ketogenic diet?
Unfortunately, I think we will find the answers to these questions sooner rather than later with the large scale experiment that now seems to be well underway.
Alessandro Ferretti recently made the observation that metabolically healthy people tend to have lower TOTAL ENERGY levels at rest (and hence have a lower HbA1c), but are able to quickly mobilize glycogen and fat easily when required (e.g. when fasting or a sprint).
Metabolically healthy people are both metabolically flexible and metabolically efficient.These people would have been able to both conserve energy during a famine and run away from a tiger and live to become our ancestors, while the ones who couldn’t didn’t.
Similar to RD Dikeman, John Halloran is an interesting case. He has been putting a lot of effort into eating nutrient dense foods, intermittent fasting and high-intensity exercise.
He is also committed to improving his metabolic fitness to be more competitive in ice hockey. His resting heart rate is now a spectacular 45 bpm!
And he’s been able to lose 10kg (22lb) in one month!
At 5.2mmol/L (i.e. glucose of 4.0mmol/L plus ketones of 1.2mmol/L) John’s TOTAL ENERGY is well below the average of the 26 people shown in the glucose + ketone chart above. It seems excellent metabolic health is actually characterised by lower TOTAL ENERGY.
MORE is not necessarily BETTER when it comes to health.
Fast well, feed well
To clean up the data a little I removed the ketones vs glucose data points for a couple of people who I thought might be suffering from pancreatic beta cell burnout and one person that was taking exogenous ketones during their fast that had a higher TOTAL ENERGY. I also removed the top 30% of points that I thought were likely high due to measuring after high-fat meals or coffee.
So now the chart below represents the glucose and ketone values for a group of reasonably metabolically healthy people following a strict ketogenic dietary approach, excluding for the effect of high-fat meals, BPC, fat bombs and the like.
The average ketone value for this group of healthy people trying to live a ketogenic lifestyle is 0.7mmol/L. Their average glucose is 4.8mmol/L (or 87mg/dL). The average TOTAL ENERGY is 5.5mmol/L or 99mg/dL.
blood glucose (mmol/L)
total energy (mmol/L)
The table below shows this in US units (mg/dL).
It seems we may not necessarily see really high ketone levels in our blood even if we follow a strict ketogenic diet, particularly if we are metabolically healthy and our body is using to ketones efficiently.
the real magic of ketones
When we deplete glucose we train our body to produce ketones.
This is where autophagy, increased NAD+ and SIRT1 kicks in to trigger mitochondrial biogenesis and ENDOGENOUS ketone production (i.e. the free ones).The REAL magic of ketosis happens when all these things happen and ketones are released as a byproduct.
I do not believe that simply adding EXOGENOUS ketones will have nearly as much benefit to your mitochondria, metabolism and insulin resistance as training your body to produce ENDOGENOUS ketones in a low energy state.
Everything improves when we train our bodies to do more with less (e.g. fasting, high-intensity exercise, or even better fasted HIIT). Resistance to insulin will improve as your insulin receptors are no longer flooded with insulin caused by high TOTAL ENERGY building up in your bloodstream (i.e. from glucose, ketones and even free fatty acids).
Driving up ketones artificially through EXOGENOUS inputs (treating the symptom) does NOT lead to increased metabolic health or mitochondrial biogenesis (cure) particularly if you are driving them higher than normal levels and not using them up with activity.
You may be able to artificially mimic the buzz that you would get when the body produces ketones ENDOGENOUSLY, however, it seems you may just be driving insulin resistance and hyperinsulinemia if you follow a “MORE is better” approach.
Simply managing symptoms with patented products for profit without addressing the underlying cause often doesn’t end well.
Perhaps as more exogenous products come to market without the marketing hype that that comes with multi level marketing (e.g. Julian Baker’s Insta Ketone which are a sixth of the price of the Pruvit products) people will get to see if they really do anything useful.
Just like having low blood glucose is not necessarily good if it is primarily caused by high levels of EXOGENOUS insulin coupled with a poor diet or having lower cholesterol due to statins, having high blood ketone values is not necessarily a good thing if it is achieved it by driving up the TOTAL ENERGY in your blood stream with high levels of purified fat and/or EXOGENOUS ketones.
When we feed our body with quality nutrients we maximise ATP production which will make us feel energised and satisfied. Nutrient dense foods will nourish our mitochondria and reduce our drive to keep on seeking out nutrients from more food.
Greater metabolic efficiency will lead to higher satiety, which leads to less food intake, which leads to a lower TOTAL ENERGY, increased mitochondrial biogenesis, improved insulin sensitivity and lower blood glucose levels.
Prioritising nutrient dense real food is even more important in a ketogenic context.While we can always take supplements, separating nutrients from our energy source is never a great idea, whether it be soda, processed grains, sugar, glucose gels, HFCS, protein powders, processed oils or exogenous ketones.
the best exogenous ketone supplement
If your goal is metabolic health, weight loss and improving your ability to produce ENDOGENOUS ketones, then developing a practice of FEASTING and FASTING is important.
To start out, experiment by extending your fasting periods until your TOTAL ENERGY is decreasing over time. This will cause your circulating insulin levels to decrease which will force your body to produce ENDOGENOUS ketones from your ENDOGENOUS fat stores.
If you want to measure something, see how low you can get your glucose levels before your next meal. Then when you do eat, make sure you choose the most nutrient dense foods you possibly can to build your metabolic machinery and give your mitochondria the best chance of supporting a vibrant, active and happy life.
As my wise friend Raymund Edwards keeps reminding me, FAST WELL, FEED WELL.
Living a long, vibrant, healthy life is a common goal. But what can we do to extend our health span?
Should we eat more fruit and veggies? Less processed foods? More protein? Less protein? Exercise more? Lose weight? Sleep more? Get more sun? Less blue light?
The numerous facets of health and longevity are complex and above my pay grade. However, I am willing to add my two cents to the discussion in the areas of insulin, blood glucose, fasting and nutrition along with some input from people I respect.
Dr Ted’s top tips
My wise friend Dr Ted Naiman recently commented on the topic of longevity.
I see centenarians at work, and as far as I can tell it is important to be:
– insulin sensitive,
– active, and
– relatively strong
Extreme careful protein restriction? Not so much. I for one will focus on the first three.
Not only is Ted enviably buff, he also has a neat way of condensing wisdom into short bites that are worth unpacking a little further.
The leading causes of death in adults in the western world (i.e. heart disease, stroke, cancer, Alzheimer’s and Parkinson’s) all have something in common. They are diseases of modern society, related to metabolic health and exacerbated by excessive insulin and / or high blood glucose levels.
People who live longer still die from these same diseases, they just succumb to them later.
This chart (from Barbieri, 2001) shows that insulin resistance generally deteriorates with age. However if you’re one of the few to make it past 90 then chances are your insulin resistance is pretty spectacular!
Ted’s infographic below explains how insulin resistance and metabolic syndrome leads to hyperinsulinemia (elevated insulin) and hyperglycaemia (elevated blood glucose) and then to heart disease and many of the other diseases of modern society.
The chart below indicates that you have a much better chance of delaying the top two causes of death in western society (i.e. heart attack and stroke) if you have a lower HbA1c.
And your chance of maintaining a big brain that is free of Alzheimer’s and Parkinson’s (causes of number four and five) seems to be greatly improved if you keep your blood glucose levels low.
We’ll come back to cancer, cause of death number three, a little later.
While you might be able to make an argument for longevity around restricting protein or even calories based on laboratory experiments, people live in the real world and need adequate strength to move around, stay active and be relatively strong. People who are lean and strong intuitively look healthy and attractive to us.
Longevity research is typically done in yeast, worms, mice or other animals who live protected in captivity. Unfortunately, real people don’t live in protected laboratory environments in a petri dish. We live in the real world where real people break.
Loss of muscle as we age (i.e. sarcopenia) is a major issue. Many older people become brittle and weak. They take a fall, break their hip and never get up. Maintaining strength and lean muscle mass is important.
You don’t see many fat animals in the wild, but at the same time you don’t see skinny animals, unless they are sick. Animals that survive in their natural environment are lean, strong and fast. They have to be to survive, to catch food and avoid being eaten.
Humans in the wild also tend to be strong and lean.
Similar to Ted Naiman, Ian Rambo (pictured below), 62, is a fan of intermittent fasting and a moderate protein diet. Rambo doesn’t look like he’s about to trip and break his hip any time soon.
A lot can be said about exercise, longevity and metabolic health.
Peter Attia, who recently left NUSi to go back to practice medicine with a focus on longevity, says:
Glucose disposal is everything. The best way to get there is by increasing the muscle’s capacity to take up glucose and make glycogen, and that’s best accomplished through lifting heavy weights. Doing so also increases health span (i.e. reducing injuries, lowering pain, and increasing mobility through life).
Exercise depletes the glucose in our blood, liver and muscles and causes us to tap into our fat stores. But it’s more than just about using up energy.
As metabolic health and mitochondrial density improves through exercise, our fat oxidation rate increases. We become metabolically flexible which means that we can easily use glucose or fat for fuel. Once we improve our fitness and insulin sensitivity we get to the point that we can even obtain some of the glucose we need from fat.
My friend Mike Julian commented:
Every triglyceride that is broken down gives up one glycerol molecule. Two glycerol molecules will make one glucose. So the more fat we are capable of burning, the more glucose we can make from fat oxidation, thus the better we get at restoring muscle glycogen without eating carbohydrates.
Also the glycogen that we do burn produces lactate, which is then recycled to make more glucose in the cori cycle, which also contributes to muscle glycogen stores during recovery.
The goal is to increase mitochondrial density so that we are very good at oxidizing fats. When we have poor mitochondrial density we are far more prone to switching over to anaerobic metabolism at low activity levels and anaerobic activities require glucose.
So if we can’t burn fat at high rates due to low numbers of mitochondria, we can’t make much glucose from glycerol via fat oxidation, so in turn our bodies go to plan B which is to make it out of amino acids in order to make up for the rest of what it needs.
So if you increase your mitochondrial density through exercise, you’ll oxidize a higher volume of fat, which will give a higher yield of glucose from glycerol and thus reduce your body’s need to break down aminos from dietary protein and lean mass.
Post exercise increased fat oxidation due to mitochondrial density produces more ketones during the recovery period which get used preferentially so the increased glucose production during that time can go towards refilling of glycogen stores rather than be oxidized for energy. This is why many top keto athletes will fast for a few hours post training. If they eat straight away they miss out on this phenomenon and actually will recover slower.
Building on the prior trials in yeast and worms, the current dietary restriction longevity experiments in rhesus monkeys are looking positive. You can see the monkey on the right who has been living on 30% less calories looks younger and healthier than the monkey on the left who is the same age.
The monkeys who eat less have less age related disease and live longer.
While avoiding excess energy intake is beneficial, there are differing opinions on how this translates to humans in the real world in terms of increased life span.
Peter Attia says:
Most people in this space, the super-in-the-weeds people on this topic that I’ve spoken with at length, do not believe caloric restriction actually enhances survival in the wild.
Nobody disputes that for most species it enhances survival in the laboratory, but once you get into the wild, you’re basically trading one type of mortality for another.
So many things in life are a balance and involve compromise. While you need adequate nutrition to be strong and active, our bodies also age more slowly if we don’t subject ourselves to excess energy.
Another problem with calorie restriction is that unfortunately most of us don’t have the self-discipline to limit our food intake all the time. When we do eat we find it hard to stop until we are satisfied. Our survival instincts don’t know about the studies in the monkeys, the worms and the yeast.
Most people find it hard to maintain constant caloric restriction when they have free will and unlimited access to food. And then the cruel trick for people who do have the discipline to consistently reduce their energy intake is that the body will scale back its energy expenditure to stay within the reduced energy intake.
“Complete abstinence is easier than perfect moderation.”
So if caloric restriction doesn’t necessarily work, then what’s the solution? Jason Fung makes a compelling case for the benefits of intermittent fasting rather than chronic calorie restriction.
When there is a lack of food a process called autophagy (from the Greek auto, “self” and phagein, “to eat”) kicks in and we turn to our own old cells for nutrients. Autophagy is nature’s way of getting the energy we need when we don’t eat in addition to cleaning out the old junk in our bodies and brains. When we get to eat again we build up new, fresh healthier cells.
But this process of cell clean up and regeneration cannot occur without giving the body the chance to clean out the old cells first. We regenerate and slow aging when we don’t always have a constant supply of energy. One of the advantages of intermittent fasting over simply reducing calories is that you get a deeper cleanse of the old cells with total restriction of energy inputs.
In the video below David Sinclair explains how our body makes a special effort to repair itself when there is a lack of food. In a famine your body senses an emergency and sends out Sirtuin proteins to maximise the health of our mitochondria to increase the chance that you will survive the famine and have the best chance of living until a time when food is more plentiful and you can reproduce and pass on your genes. Unfortunately, this emergency repair function just doesn’t happen when food is plentiful. They’re working on drugs that will mimic this effect, but in the meantime, intermittent fasting is free.
Many people hypothesise that restricting protein is an important component to slow aging.
Dr Ron Rosedale talks a lot about the dangers of glycation and the kinase mTOR. His hypothesis, as articulated in the Safe Starches Debate and AHS 2012, is that we should avoid carbohydrates to avoid the dis-benefits of glycation, particularly as we can get the glucose we need from protein and to a lesser extent from fat. When you see that all the major diseases of aging are correlated with high blood sugars and high insulin levels you might think that he is onto something.
In his AHS 2012 talk Rosedale discusses the dangers of mTOR (mammalian target of rapamycin). mTOR is activated when we eat protein and raise insulin and leads to suppression of autophagy. In view of this Rosedale recommends relatively low levels of protein for people with diabetes (e.g. 0.6g/kg) and even lower for people who are battling cancer (e.g. 0.45g/kg).
Vegan luminary Dr Michael Gregor points to the various drawbacks of excess dietary protein and makes a compelling case for restricting animal protein by focusing on plant foods rather than caloric restriction or intermittent fasting.
There’s a fascinating August 2015 paper by Valter Longo et al that gives an overview of the current thinking in longevity. While it mentions protein restriction as a possible area for future investigation, discussion of protein restriction generally seems to be in the context of intermittent restriction with subsequent re-feeding.
To date, very few studies have been performed in humans on the potential beneficial effects of protein and/or amino acid restriction on aging processes or age-associated chronic diseases.
There are obvious benefits in having periods where the body can clean out old proteins, however you also need high quality nutrition to build back the new shiny parts.
While I have gone to great lengths to bring attention to the fact that protein contributes to the insulin load of the diet, I struggle with the concept of chronic protein avoidance when so many of the things I read talk about the mental health benefits of protein, the benefits of lean muscle mass for metabolic health, the satiety benefits of protein and the importance of lean muscle as we get older to ensure we can be active and strong rather than brittle.
Like everything though it’s a balancing act. Binging on protein supplements and egg whites to get big and jacked is not going to lead to optimal health and longevity. Some of these guys are even injecting extra insulin for its anabolic hypertrophy effects on top of the anabolic hormones. This is not healthy and not natural.
So how much protein do you need when you do eat? I think you need enough to be strong and active but at the same time without raising insulin and blood sugars and decreasing ketones.
Lean muscle = good
Insulin sensitivity = good
Excess body fat = bad
High insulin = bad
There’s also a growing momentum around the metabolic theory of cancer (the number three leading cause of death) which hypotheses that excess glucose feeds cancer growth and restricting glucose through a therapeutic ketogenic diet with intermittent fasting will reduce your risk of cancer.
When you hear Seyfriend talk he seems very proud of and excited about the glucose : ketone index (GKI) which he developed as a proxy for a person’s insulin levels. As you can see in the chart below, as our blood glucose levels decrease ketone levels rise.
More than blood glucose or ketones alone, the relationship between your blood glucose and ketones seems to be a good proxy for your insulin sensitivity.
It seems that someone with a GKI of less than 10 has fairly low insulin levels, someone with a GKI of less than 3 has excellent metabolic health, while someone battling cancer might want to target a GKI of 1.0.
Reducing the insulin load of your diet can reduce your glucose levels, increase your ketones and reduce your risk of metabolic syndrome and the most prominent causes of death (i.e. heart disease, stroke, cancer, Alzheimer’s and Parkinson’s).
Just to be clear, you people who achieve these excellent insulin resistance levels don’t get get there by simple adding more fat to their morning coffee but through disciplined intermittent fasting which tends to lead to reduction in body fat which improves insulin resistance.
finding the optimal balance
On one extreme too much food will make us fat and insulin resistant and stop the body from repairing itself.
On the other extreme calorie restriction will make us frail and vulnerable to disease and accidents.
So how do we find the middle ground?
On the topic of carbohydrates Peter Attia says:
You want to consume basically as much glucose as you can tolerate before you start to get out of glucose homeostasis. For me there’s a different number than for the next person, and you have to find what the level is.
I’ve been wearing a continuous glucose monitor for several months now. Every day I just have it spit out my 24-hour average of glucose plus a standard deviation, and I now know my sweet spot. I like to have a 24-hour average of between 91 and 93 mg/dL with a standard deviation less than 10.
We can’t measure insulin in real time. To me, the Holy Grail would be to have an area under the curve of insulin, but this becomes a pretty good proxy.
It’s fascinating to see that Attia, who is a super fit semi pro athlete is going to the effort of wearing a continuous glucose meter full time. CGMs are generally worn by people with type 1 diabetes like my wife.
The process he is describes of reducing dietary glucose intake to a point where blood glucose levels are normalised is essentially the process used by the people we see who are managing type 1 diabetes as well as possible.
The food insulin index testing measured the area under the curve response to various foods (i.e. what Attia describes as the Holy Grail) and has been really useful for us to understand which dietary inputs cause the greatest blood glucose swings and require largest amounts of insulin.
I think the reason that Attia is recommending ‘as much glucose as you can tolerate’ is to fuel your energy needs for activity, maximise nutrition and dietary flexibility. This level of blood glucose control will give him an HbA1c of 4.8% which will put him in the lowest risk category for the most common diseases of aging. But to maintain such a tight standard deviation he’s going to be managing the net carbs and protein in his diet so his blood sugar doesn’t go over 100mg/dL or 5.6mmol/L too often.
Dr Roy Taylor recently released an interesting paper where he proposes that each person has a personal fat threshold. Rather than the BMI chart or body fat, there is a certain level at which the body fat becomes inflamed and insulin resistant which leads to diabetes and all the issues related to metabolic syndrome. What this means in practice is if your blood glucose levels are rising above optimal you need to eat less to lose body fat.
When it comes to protein Attia says:
What I’m telling my patients is really you only need as much protein as is necessary to preserve muscle mass.
You have a sliding scale, which is carbohydrate goes up until you hit your glucose and insulin ceiling, protein comes down until you’re about to erode into muscle mass and slip into positive nitrogen balance, and then fat becomes the delta.
So in somebody like me, that’s probably about 20% carb, 20% protein 60% fat.
I’ve done everything from vegan to full ketogenic. I’ve experimented with the entire spectrum of religions, but nevertheless, that’s the framework.
It’s worth noting here that this quote from Peter is in the context him talking at length about mTOR, ROS, glucose control and protein restriction. Attia is one of the smartest guys in nutrition, medicine and anti-aging science, but he’s not avoiding protein. He’s making sure he gets enough to maintain lean muscle mass but not so much that it messes with his glucose levels or requires a significant glucose response.
Attia also talks about maximising glucose and minimising protein to normalise blood glucose and insulin. Given that the focus is on managing insulin levels, I think you could also take the opposite approach to minimise carbs and maximise protein as much as you can without disrupting glucose or losing ketones. People with type 1 diabetes will tend to consume medium to higher protein levels (which provide glucose but without the same degree of glucose swing) with lower levels of carbohydrates.
Or alternatively find your own balance of net carbs and protein that gives excellent blood glucose levels and some ketones.
When it comes to finding the optimal level of protein and energy Dr Tommy Wood said:
The anti-IGF-1 (insulin like growth factor) crowd confuse me. Lots = bad (cancer). Very little = also bad (sarcopenia and broken hips).
One of the pioneers in the field of longevity is Roy Walford, who developed the concept of Calorie Restriction with Optimal Nutrition (CRON). Many of the ideas in this article and the blog overall are built around Walford’s ideas regarding optimising nutrition for health and longevity.
While Walford lived his theories in practice, he unfortunately died at 79 of ALS so we didn’t really get to find out whether calorie restriction delayed the major diseases of aging for him. The pictures below are taken of Dr Walford before and after two years living in Biosphere 2.
Walford was the crew’s physician and meticulously recorded the health markers of the Biosphere 2 ‘crew members’. It’s interesting to see how markers like the BMI chart, glucose, insulin and HbA1c all improved markedly with the semi-starvation conditions during the experiment, however they reverted to more normal levels after resuming normal eating.
If we are going to fast and / or restrict calories to optimise our metabolic health it’s even more important that we make sure that the food we do eat, when we eat it, provides all the nutrients that we need to thrive and build back new shiny parts of our body. Unfortunately it seems that the optimal nutrition component of Walford’s CRON concept is not discussed much these days.
So what does all this mean? What do we know about maximising our metabolic health and avoiding the primary diseases of aging?
Is too much energy bad… yes.
Is eating all the time bad…. yes.
Is excess protein bad… maybe, maybe not, however the vegans would say that we should avoid animal protein and stick to only plant based foods.
Are excess carbohydrates bad… maybe, maybe not, however the low carb / keto crowd would say that you need to avoid carbohydrates because they raise your insulin.
Is excess protein and excess non-fibre carbohydrates bad… most likely, yes.
Both carbohydrates and protein will raise insulin, blood glucose, IGF-1 and upregulate mTOR which all accelerate aging.
In the end though we have to eat. We are programmed for survival. While not eating too much and intermittent fasting are important considerations, when we do eat though we should maximise the nutrient density and prioritise foods that do not not raise our insulin and blood glucose levels. I think if you get that right a lot of the other things will follow.
There is no perfect dietary solution for all. What is best for you will come down to your situation, goals and preferences.
Some people will prefer zero carb with lots of meat.
Some people feel strongly about avoiding animal products and do well on a plant based diet with minimal processed foods.
Some will aim for a therapeutic ketosis approach to tackle major metabolic issues.
All of these extremes are viable but a balance somewhere in the middle might be easier to maintain in the long term while also maximising the nutrient density of the calories we consume.
What is almost certainly dangerous for most people is the low fat, high insulin load approach that has been recommended for the past few decades and seems to have led to increased consumption of low nutrient density highly processed food products by many.
It has been a transformational journey for RD Dikeman since his son Dave was diagnosed with Type 1 Diabetes, both as a parent and for himself as he has implemented a regimen of what he likes to call “meal skipping” (a.k.a. intermittent fasting) guided by his own blood glucose levels.
I came across Dave Dikeman, a young man with Type 1 Diabetes, in Episode 831 of Jimmy Moore’s LLVLC Show. I still remember ten year old Dave saying “finger pricks now or amputations later, the choice is pretty simple”. Dave’s pragmatic attitude to his condition was another light bulb moment in our family’s journey to learning to manage diabetes.
It has also been quite a journey for RD Dikeman, Dave’s dad, who recently posted a few comments on the Optimising Nutrition Facebook Group that I thought were worth capturing.
I’ll tell you a quick story about how this whole low carb thing started.
Dave is near death, in the hospital, diagnosed with T1. The doctor rolls in to meet us. A kindly doctor – no Bernstein – but a very kindly man (he took an injection of insulin to show Dave not to be afraid).
So the doctor is talking to Dave and finds out they both went to the same school. So there’s some kinship. And the doctor recognizes that Dave is a pretty sharp guy and Dave starts asking questions ‘will I die young?’ And Doc is brutally honest ‘you have to control your blood sugars – amputations, blindness and those things are on the table’. And doc starts to give us a lecture on how to do that.
He has an easel and a sharpie. Anyway, he draws a rollercoaster blood sugar graph and he says ‘carbo makes blood sugar go up and insulin go down and you want to be between 80 and 180 (sigh) mg/dL.’
And Dave goes ‘I just won’t eat carbo’. TRUE STORY.!
And ME!! I interrupt and say (throw me down and kerb stomp me everyone) ‘You need carbo for… ENERGY’. LOL!
So I spent the next month force feeding Dave oatmeal. I am heckled daily for this. Every time there is oatmeal. Oatmeal on a TV commercial. Oatmeal at restaurant. Heckled!
About a month later guess who discovered ‘The Bernstein Book‘!!! NOT ME!! It was Roxanne (my wife). So that is two fails for me.
I will say the happiest moment of my life was reading Bernstein’s ‘law of small numbers’. I knew then that we had a way out of this mess.
Being 100% wrong never felt so good. I have a good leader. The whole thing was his idea.
Since then, RD has become passionate about the low carb way of eating and helping other people learn more about diabetes. He is an admin on the Type One Grit Facebook Page which is a great source of support and inspiration for people with Type One Diabetes. He and Dave also produce Dr Bernstein’s Diabetes University which captures nuggets from Dr B on YouTube.
RD lives low carb theory…
I don’t eat any carbohydrate-glucose foods. No sugar, manipulated sugar fruits, grains or starch. Ever. Carbs are only from fibrous veggies and nuts.
…and it seems to be working.
Dr Bernstein’s recommended target blood glucose is 83mg/dL (or 4.6mmol/L) with a recommendation that people with Type 1 Diabetes actively work to keep within a ten point range of this target number (i.e. 73 to 93mg/dL or 4.0 to 5.2mmol/L).
Dr B tells the story of how, back in the day, blood glucose meter sales reps would come to his office. He would get them to demonstrate how it worked by testing it on themselves so he could see their blood glucose number. Sure enough, the blood glucose levels of these healthy young non-diabetic sales reps was always around 83mg/dL.
Since then there has been plenty of research that showing the benefits of having an average blood glucose level of around 83mg/dL including reducing your risk of cancer, obesity, heart disease and a range of other metabolic issues.
Some people operate happily at the lower end of this range, particularly if they are younger and / or insulin sensitive and producing ketones. Generally though, the body of someone with a healthy metabolism will bring them back to a blood sugar of around 83mg/dL (or 4.6mmol/L).
Not too high. Not too low. Just right.
The table below shows a generalised relationship between blood glucose, ketones, HbA1c and the glucose : ketone ratio (GKI). There’s no perfect number for everyone, however typically the lower your HbA1c, without using blood glucose lowering medications, the lower your risk of metabolic syndrome and related diseases (see the Diabetes 102 article for more details).
RD is not technically diabetic himself however he understands the dangers of high blood glucose levels. RD found that the low carb way of eating helped him lower his own blood glucose, however he still wasn’t consistently achieving Dr Bernstein’s target blood glucose level of 83mg/dL.
What he did find was that when he waited to eat his blood glucose would come down as the body used up the glucose in his blood. Over time RD developed a practice of meal timing guided by his glucose meter that finally enabled him to optimize his own blood glucose levels.
My blood sugar tells me when it’s time to get some insulin sensitizing exercise at the gym also.
I would say if blood sugar is above normal (83 mg/dL) then beta cells are ‘on’ and insulin is a fat storage hormone (obviously other functions).
Chronically elevated blood sugar levels can be a sign that you are eating too much and/or too often.
You can use your blood sugar to help you refine your meal timing to optimise your weight and blood sugar levels.
Delaying your next meal allows your body to use up the stored energy in your bloodstream, liver and body fat stores.
Over the long term, a decreasing weight on the scale can be a good indicator that you are not overeating. However, in the short term, blood glucose levels can be a more useful indicator of whether you really need to eat now or if you are just eating because out of habit, boredom, entertainment or comfort.
The below table outlines a protocol that will help you to use your blood sugar meter as a fuel gauge to reach your diabetes and fat loss goals.
if hungry, eat higher insulin load foods and delay exercise
This approach is not intended for people who do not produce enough insulin (i.e. type 1 diabetes, type 1.5, LADA and MODY) but rather for people who are insulin resistant and produce large amounts of insulin but still have high blood sugar levels (i.e. pre-diabetes and type 2 diabetes).
Eating frequently will keep your insulin and blood sugar levels consistently high, particularly if you tend to consume foods with a high insulin load.
By contrast, reducing meal frequency enables blood sugar and insulin levels to decrease.
High levels of insulin keep fat stores from being used glycogen trapped in the liver while the energy in the bloodstream is used up.
When our adipose tissue can’t absorb any more energy, it becomes insulin resistant. This makes it harder for insulin to get into our major fat stores on the body. But your pancreas continues to ramp up insulin production in order to reduce high blood glucose levels in the blood and to keep the glucagon stores in the liver. With elevated insulin levels and more insulin resistant adipose tissue the excess energy now starts to get stored in more sensitive parts of the body such as our liver, pancreas, heart, brain and eyes.
Delayed eating allows the energy in the bloodstream to reduce. Once the liver glycogen stores start to be depleted, then the body finally turns to body fat for fuel.
Decreasing body fat, particularly from the liver, pancreas and kidneys leads to improved insulin sensitivity and eventually leads to normal blood sugar levels.
Eating larger meals with more carbohydrate causes your blood sugar to stay higher for longer. Conversely, consuming smaller meals with a lower insulin load allows your blood sugar to return to baseline faster.
When to eat
Your blood sugar metre can be a useful tool to understand whether you really need extra energy or whether you could skip a meal or two or not eat for the day.
If you have some level of insulin resistance, then chances are your blood sugar levels will be higher in the morning due to liver glycogen being released as your body prepares for the day. This is sometimes referred to as Dawn Phenomenon.
If you are insulin resistant the insulin secreted by your pancreas doesn’t keep up with the release of glucose into the bloodstream, and hence your blood sugar will be high.
If you test your blood sugar in the morning and it’s higher than your current average, then you might want to delay eating until your blood sugar comes back down. This may mean eating your first meal early afternoon followed by an early dinner (i.e. 16:8 intermittent fasting). Alternatively, if you consistently find your blood sugars are high in the morning you could skip dinner avoid eating later in the evening, which would help to lower morning blood sugar.
There is no perfect fasting routine for everyone. Over time you’ll find one that suits you, and you will be able to calibrate your feeling of hunger with your actual need for food based on your blood sugar levels and reduce the frequency of testing. Once you’ve established new habits you will no longer need to rely on the glucose metre.
Some people find that they can ‘eat to satiety’. However, others find that they tend to overeat and ‘binge’ after a long period between meals, particularly on energy dense and nutrient poor hyper-palatable foods. Using a metric like your blood sugars is useful to make sure fasting is providing the outcomes you want. Tracking your glucose levels can help you ensure that your blood sugar levels are decreasing but not so much that you will lose control of food quality or quantity when you eat next.
Tailored just for you
Many people agree that intermittent fasting is a good idea, but many people get confused about what frequency is best for them.
What if you just really feel hungry but it’s not “time to eat” yet!?!?
The advantage of using your blood sugar level as a guide versus a regimented intermittent fasting protocol or a fixed calorie intake is that it accounts for the energy your burn as well as what you’re eating.
You could argue that tracking your blood sugars could be more useful than calorie counting. Ensuring that your blood sugars are decreasing by delaying eating will ensure that you are running at an energy deficit and pulling fuel from the energy stores on your body.
The body is a complex adaptive system, and our energy expenditure will vary based on many factors beyond our ability to measure and manage.
Eating is not bad. You need to balance your intake with your energy expenditure while getting the nutrients you need to thrive. This can be a challenge when we are surrounded by cheap hyper-palatable nutrient-poor foods.
Refining your feasting/fasting route around your blood sugars will help you to fine-tune when and how much you eat to your actual requirements.
Your blood sugar meter can help you understand whether your hunger is real and help you to refine your eating regimen.
If your blood glucose levels are lower than your average, then your insulin levels will be decreasing, and you’ll be using up your stored body fat and liver glycogen.
If your blood sugar levels are increasing, then it’s likely you’re overeating and/or too often which means you’ll be storing energy as fat on your body.
When using this approach, you can eat to eat to satiety. But if you overdo your intake at this meal it will mean that you will be delaying your next meal a little longer.
You could even use this approach to make sure you don’t overdo the refuelling and keep the insulin load of your meals such that your blood sugar doesn’t go over say 120 mg/dL (or 6.7 mmol/L). A blood sugar level above this is a sign that your liver glycogen stores are full and spilling over into your bloodstream.
Some people find that they tend to eat less overall when intermittent fasting compared to trying to eat numerous ‘small’ meals. Saint Augustine wisely said:
“Complete abstinence is easier than perfect moderation.”
I think this also applies to our meal timing and portion sizing.
By choosing to eat only when your blood sugar is below YOUR target blood sugar level, you can tailor the approach to your current situation and metabolic health.
Waiting until your blood sugar reaches optimal levels (i.e. 83mg/dL or 4.6mmol/L) is not realistic for most people. It’s best to start from where you are now and work towards optimal.
In the study Adherence to hunger training using blood sugar monitoring: a feasibility study, the researchers found that participants did much better when they set their own personalised blood sugar target rather than waiting until their blood sugar levels reached some optimal target before eating.
The other noteworthy observation from this study was that people who were obese lost a significant amount of weight!
Overweight participants achieved significant weight loss over the two-week period, with an average loss of 1.5 kg (95 % CI 2.2, 0.9) and a corresponding reduction in BMI of 0.6 kg/m2 (95 % CI 0.3, 0.8), p < 0.001). By contrast, lean participants maintained their weight.
The end game
The long-term goal is to achieve an optimal HbA1c of 4.5% which equates to an average blood sugar level of 83 mg/dL (or 4.6 mmol/L).
There are plenty of excellent reasons to keep your blood glucose and insulin levels in check such as reducing your risk for cancer…
…heart attack, stroke and a whole range of western diseases.
People with Type 1 Diabetes following Dr Bernstein’s protocol try to keep their blood glucose within ten points of the optimal target level of 83 mg/dL (4.6 mmol/l). This means that they will dose with insulin when their blood glucose rises above 93 mg/dL (or 5.2 mmol/l) and then eat to bring their glucose levels back up when they drop below 73mg/dL (or 4.0 mmol/L).
Someone who has a functioning pancreas but is struggling with insulin resistance, hyperinsulinemia and/or obesity can use a similar process to manage their blood glucose and insulin levels. However, rather than dosing with insulin to bring their blood glucose down they simply delay eating until they burn through the excess glucose in their bloodstream.
Waiting to eat until your blood glucose levels are below your recent average will ensure that they are decreasing over time. Most glucose meters will display the average glucose level for the last seven, fourteen and thirty days, so it is easy to tell what your current target is.
On the Freestyle Lite metre (our family favourite) you can show your 4, 14 and 21-day average blood sugar by pressing the ‘m’ button on the left-hand side of the metre.
If you’re eager, you could go to the trouble of graphing your blood sugar numbers, However, in the end, if your seven-day average is less than your fourteen-day average then you’re moving in the right direction.
Over time you want to see your average blood glucose levels coming down. If you find your blood glucose levels drifting up, it’s a sign that you need to intensify your fasting regimen.
If working out your average blood sugar level is a bit complex you can just set an arbitrary target of say 10 mmol/L on waking. If after a while you find you are mostly under waking under 10mmol/L you can change your target to 9.0 mmol/L, then 8.0 mmol/L, then 7.5 mmol/L, then 7mmol/L and so on.
Normalising blood sugar and insulin will often help people to lose weight, particularly if you’re insulin resistant. However, some people will still need to pay attention to continuing to lose weight once their blood sugar and insulin is normalised.
Will optimal blood glucose levels guarantee weight loss?
While normalising blood sugars and insulin sensitivity will usually help you improve your body weight, it is possible to have excellent blood sugars and still be overweight (e.g. by eating a lot of fat that doesn’t raise blood sugar but doesn’t allow body fat to be burned).
The chart below shows Rebecca Latham’s blood sugar levels decreasing over a period of three months. Once your average blood glucose level drops below 83mg/dL or 4.6mmol/L, then you may do better switching to using a weight target rather than a glucose target to drive your eating frequency.
If you have achieved excellent blood sugar and still want to lose weight, you can transition to using your target body weight as a trigger to decide whether to eat that day as detailed in the article How to use your bathroom scales as a fuel gauge.
The chart below shows Rebecca’s weight loss to achieve her goal over twelve months and then transitioning to a maintenance regimen during 2017.
When not to use this approach
Exercise may raise your blood sugar in the short-term due to the body dumping glycogen from your liver into the bloodstream to fuel your activity. If you don’t eat before or after exercise, your body will have to replenish the glycogen stores from the energy stores on your body.
There will be times when you’re hungry, or it will be appropriate to eat for social reasons such as a party, family gathering, etc. Periodic fasting and then feasting is a regular part of our culture. Tracking your blood glucose levels will help you get back on track after these indulgences. Personally, I tend to employ this approach after feasting periods such as Christmas to recalibrate my appetite.
You should also keep in mind that other things affect blood sugar including stress, sleep, sickness, hormones and exercise that you will need to be mindful of when deciding whether to delay a meal due to your blood sugar being high.
Fasting may not be ideal if you’re stressed, sick, not sleeping well and/or are pushing the exercise envelope. During these times, it may be better to focus on life maintenance and listen to your appetite and leave your fasting until the rest of your life is under control.
If you are taking insulin or other blood sugar lowering medications, you will need to make sure they are reduced to make sure your blood sugars don’t drop too low. Otherwise, you may have to eat to raise your blood sugar due to the excess medication.
The problem with injected insulin or many other diabetes medications is that, while it may help to reduce blood sugar levels, it also drives the energy back into the cells rather than allowing the stored energy to flow out of storage.
High blood sugar levels can be a sign that you’re stressed, exhausted or your hormones are out of whack (including time of the month for females), all of which will lead to insulin resistance. You can use Heart Rate Variability to track your stress and exhaustion with an app such as Elite HRV which enables you to see when you’re exhausted and need to back off and rest.
If you just don’t feel like fasting and your blood sugar levels are high it’s probably a sign that you need to rest, relax, sleep, meditate, see some real sunlight during the day and stop gazing into the artificial sun on your devices before you go to bed. Using f.lux on your computer or blue blocking glasses after sunset is worth considering.
While longer therapeutic fasts can be beneficial, a shorter duration feast / fast cycle that brings your blood sugar levels down to below your average is likely to be more useful to improve your metabolism while reducing the extreme swings in water weight or any concerns that you’re not getting adequate protein to support lean body mass.
Will monitoring my blood sugars help me enter ketosis?
The most straightforward approach is just to measure your blood sugar levels when you feel hungry and not eat until they drop below your target level. You could still use this method even once you have improved your insulin sensitivity to losing weight by targeting even lower blood glucose levels before eating.
The chart below shows the sum of blood glucose and blood ketone levels for people on a low carb or ketogenic diet. While a low carb diet helps to stabilise blood sugar and removes hyperpalatable foods when benefits a many people in terms of weight loss and energy levels, some of the major benefits are reserved for the periods when we are in a low energy stage (e.g. reduced insulin levels, autophagy, mitochondrial biogenesis, increase in NAD+ and increase in SIRT1). It is in these periods of low energy that our body goes into cleansing and repair mode so it can survive through the famine to be able to reproduce in the next time of plenty.
Zooming in on the left hand side of the chart, we can see that it’s the periods when we drive the energy in our blood down through delaying eating or restricting energy intake that we get the major benefits often associated with a low carb or ketogenic diet.
You will likely have some blood ketones in your bloodstream when your blood glucose levels are low, but they may not be at the levels that many consider to be ‘optimal ketosis’. As shown in the chart below, if your blood glucose levels are at 4.5mmol/L or 80 mg/dL then you you might expect blood ketone levels to be somewhere between 0.3 and 0.7mmol/L. If your blood sugars are at 4.9mmol/L or 88 mg/dL your ketones might be somewhere between 0.4 and 1.1 mmol/L.
While measuring ketones can be interesting, they tend to be a much noisier measurement. As the glucose in your blood reduced your body will be forced to turn to your body fat stores, so you will increase your fat burning. Part of the reason that you may not see high levels of ketones in your blood though is that they are being used efficiently for fuel and not backing up in your bloodstream. So if you have limited funds for test strips and don’t want to be pricking yourself too often then I would focus on blood glucose levels.
Ketones and the glucose: ketone index
Monitoring your blood sugar will work whether you are insulin sensitive or insulin resistant, obese or healthy weight.
The body does a fantastic job of replenishing your glycogen stores and stabilising your blood glucose whether it be from carbohydrates, gluconeogenesis from amino acids or even gluconeogenesis of fat once you are highly insulin sensitive.
If you require therapeutic levels of ketosis, once you are starting to get your blood sugar levels under control, you could begin to track your ketones or the glucose: ketone index (GKI). Decreasing glucose along with rising ketones is a sign that your glycogen stores are being depleted, your insulin levels are reducing and you your hunger is a signal that you really need food.
Tracking the ratio between your glucose and ketones (GKI) and delay eating until your GKI is under a certain level could be a useful strategy if you are aiming for therapeutic ketosis for the management of chronic conditions such as cancer, Alzheimer’s, Parkinson’s or dementia.
Alternatively, you could simply not eat until your ketone levels were higher than a certain threshold. You could start with a target ketone level of 0.4 mmol/L and keep winding that up till you achieve your desired results.
However, testing blood ketones every time you feel hungry could be expensive. Many people also find that their blood ketone levels tend to decrease as they adapt to a low carb diet.
While all these things are relevant and useful, make sure to use them as tools to help you live life rather than taking over your life and stressing you out. Your goals need to be realistic and tailored to your situation. Hopefully, in time this ‘hunger training’ approach will help you build new habits around eating which will mean you won’t need to rely on the testing.
Fast well. Feed well
Keep in mind if you are eating less food less often you will need to maximise nutrient density when you do eat, including ensuring that you are getting adequate nutrients to maintain lean muscle mass over the long term.
Some people advise refeeding with high-fat ketogenic foods after a fast. While they may help keep insulin levels lower, it may not enable you to replenish the micronutrients that you lost during your fasting (particularly the minerals such as potassium, magnesium and sodium and the amino acids). It also may not be optimal to refeed on very high-fat foods if you are trying to lose body fat. Foods with adequate protein and high levels of nutrients will also be more satiating and enable you to be ready to fast again sooner.
I know personally, I tend to reach for the energy dense nutrient poor foods after a period of fasting. That’s why I developed that Nutrient Optimiser to help you fine-tune your diet based on your current level of insulin resistance.
The chart below shows a comparison of the nutrients / 2000 calories in all the foods in the USDA foods database versus the most nutrient dense foods identified by the Nutrient Optimiser algorithm. If our goal is weight loss, then these foods can be beneficial to ensure we get the nutrients we need with the minimum amount of energy.
I think what we really want when we refeed is to maximise the nutrients : energy ratio of the food we eat so we can maximise our fat loss goals and be able to fast again soon without risking nutrient deficiencies. After a period of fasting and autophagy, we want to refeed on nutritious food that will help us build back a strong, healthy body.
Best of luck if you chose to try this approach. I look forward to hearing how you go.