Data-Driven Fasting: How to Lose Weight and Reverse Type 2 Diabetes Without Tracking Your Food

Intermittent fasting has helped many people lose weight, lower their blood glucose, and reverse type 2 diabetes without the hassle of tracking their food.

But, sadly, for many others, fasting does not provide the results they had hoped for.

When we get ravenously hungry, we usually reach for energy-dense, nutrient-poor foods that quickly undo all the benefits of our sacrifice and deprivation.

To ensure long-term success, you need to find your minimum effective dose of fasting. You need to learn to stretch that stretches your body just a little, but not so much it rebels and traps you in an endless restrict-binge-restrict cycle.

More isn’t always better.  You need just enough restriction to ensure you’re moving towards your goal at a sustainable rate, but without waking your inner lizard brain. 

Data-Driven Fasting (DDF) ‘gamifies’ the process of fat loss using a few simple measurements to guide your progress.  You can personalise your eating schedule to achieve your goals by measuring what matters and ignoring the rest.

Data-Driven Fasting is a powerful, time-proven tool that has guided thousands of people toward their fat loss and blood glucose goals without tracking calories or using a rigid, one-size-fits-all fasting window. 

We are thrilled with the results from the thousands of people who have used Data-Driven Fasting to optimise when and what they eat.

To learn how to leverage the insights from your blood glucose to guide when and what to eat, read on!

BONUS: Download Free Data-Driven Fasting Book That Helped Thousands Of People Personalize Their Fasting Routine

Is Calorie Counting The Best Way to Lose Weight?

Many people try calorie counting using apps like MyFitnessPal.  But sadly, very few people achieve the long-term success they had hoped for. 

  • Most of us live unpredictable lives filled with family dinners, work lunches and impromptu parties that make it impractical to weigh and measure everything we eat.
  • While we can be disciplined most of the time, it’s those occasional meals, when your calorie-tracking app isn’t looking, that sneakily undo all your hard work.
  • Even if you could weigh and measure everything you put into your mouth, the nutrition data in your app doesn’t precisely match the foods you eat. 
  • Your body doesn’t ‘burn’ foods in the same way that calories are measured in a bomb calorimeter (pictured below).
  • Calorie-tracking apps don’t account for the thermic effect of food, which varies depending on the degree of processing and macronutrient profile.
  • Any theoretical calorie target calculated by an online macronutrient calculator is an inaccurate ‘guesstimate’. 
  • Your energy expenditure naturally adapts and changes from day to day.  Your metabolism is incredibly complex.  The energy you use each day is influenced by many factors, including,
    • your muscle mass,
    • stress,
    • activity,
    • age,
    • overall health, and
    • sleep.  
  • Eating is primal and instinctual. Your appetite ensures that you seek out the nutrients you need.  When you restrict calories, the part of your brain that governs your survival instincts (i.e., your amygdala, also known as your ‘reptilian’ or ‘lizard’ brain) perceives a starvation threat and responds to this ‘dire emergency’.  Your body responds by slowing your metabolism and driving up your hunger to ensure you eat more next time you have access to food. 
  • If you try to maintain a fixed calorie intake, ignoring your healthy hunger signals on some days and eating more than you need on others, there is a real risk that your natural and healthy appetite signals will become dysregulated.   
  • When you slash your energy intake by simply restricting calories without changing WHAT you eat, your body quickly adapts to ensure your survival and:
    • your metabolic rate slows,
    • you produce less heat,
    • you feel less energetic, and
    • your involuntary activity grinds to a halt to divert energy to your heart, lungs, kidneys, brain, and other organs essential to your survival.  

While energy is always conserved, the factors on both sides of the ‘calories in vs calories out’ equation are incredibly complex and beyond our ability to precisely measure or manipulate, even with the latest smartphone app or activity trackers.   

While we would like to believe that our conscious brain is always in control and that we can use our willpower to eat less and move more, most people are unsuccessful at self-imposed starvation over the long term.

Prolonged fasting and very low-calorie diets eventually panic our ‘lizard brain’ into wresting hunger control from our neocortex, rescuing us from what ‘Lizzy’ perceives as a starvation threat.

But fear not!  Data-Driven Fasting not only guides you, using the insights from using your blood sugar as a fuel gauge, to get to know, and even make friends with, Lizzy.   Data-Driven Fasting shows you how to tame your lizard brain by giving it exactly what it needs, precisely when it needs it.

Data-Driven Fasting is like a lullaby for a restless Lizzy—singing your inner lizard back to sleep, reassuring it that it will receive what it needs, so that you can relax into a new routine, optimised just for you, and thrive!

Counting Calories Can Cause Disordered Eating

If you’ve ever tried tracking calories, you already know that your lizard brain doesn’t like to relinquish control of your appetite to a ‘smartphone’ app. 

Eventually, frustration and anxiety mount when we discover that all the time and energy we’ve invested in tracking everything we’ve put into our mouths has failed to yield the results we’d hoped for.

Sadly, chronic food tracking can cause many people to become neurotic. A 2017 study looking at people diagnosed with eating disorders found that 75% of participants reported using MyFitnessPal. Disturbingly, 73% of MyFitnessPal users said their use of the app had contributed to their eating disorder. 

Simply trying to count calories to stay under an arbitrary target is a recipe for failure.   The simplistic manifesto of ‘eat less, move more’ drives many dieters into a futile cycle of restrict, binge, and restrict, binge, repeat.  Without consideration of how your complex metabolism and appetite work, calorie tracking is as archaic as using an abacus.  

Your Appetite Has Been Hijacked

Sadly, our natural and healthy hunger signals have been hijacked by our modern food environment, including:

  • an abundance of highly processed foods that contain both refined carbohydrates and fats — this combination of macros is rare in nature and drives us to overeat, much like we once instinctively did every autumn to build our fat stores for winter survival,
  • 24/7 food availability 365 days per year,
  • cultural cues that lead us to associate food with fun, affection, pleasure, social gatherings, and popularity, rather than the source of the nutrients we need to thrive,
  • food advertising and marketing campaigns that promote snacking and eating, and
  • ‘bait and switch’ artificial colourings, scents, and flavours trick your appetite into falsely believing processed food products contain the nutrients you need.

These factors contribute to the burgeoning ‘Frankenfood’ marketplace that perpetuates overeating and weight gain.  This change in our food environment has driven the ‘diabesity’ epidemic that, according to the World Health Organisation, now affects more than 422 million people.  

What Is The Best Fasting Schedule For YOU? 

While fasting continues to grow in popularity, there is still plenty of confusion about the ideal routine.  Is it:

After experiencing some success, many people become passionate about their favourite fasting routine, enthusiastically proselytising the version that worked for them.   But what about you?

  • How do you know which fasting plan is right for you?
  • How do you know if it’s working?
  • How can you fine-tune your routine to optimise your results?
  • How do you know your chosen schedule won’t lead to bingeing, thus negating all your arduous work?
  • What if you feel ravenously hungry, but it’s not ‘time to eat’ according to your chosen fasting approach?

What Is the Best Refuelling Schedule for You?

Imagine your best friend told you the best time to put fuel in your car at 10 am on the first Saturday of the month.  

But they drive a hybrid hatchback, have a 20-minute commute to work, and walk everywhere on the weekend.  

Meanwhile, you drive a pick-up truck, have a two-hour commute to work, and sometimes drive to the beach on the weekends. 

Following the refuelling schedule that your friend swears by will leave you out of gas and on the side of the road!  The only sensible way to decide when to refuel is to go by the fuel gauge on YOUR truck.

Just like fueling your car, there’s nothing magical about someone else’s eating schedule that means it’s also going to work perfectly for you. 

You’ll get better ‘mileage’ by dialling in your fasting routine based on your fuel gauge (your blood glucose) than by filling up on someone else’s clock-based schedule — no matter how well theirs works for them.   

Data-Driven Fasting helps you optimise your refuelling schedule to suit your unique requirements and goals by giving you an immediate insight into when your body’s fuel gauge is ‘full’ and when it is flashing ’empty’. 

What Happens When You Run Out of Fuel (or Fast for Too Long)? 

While you don’t want to fuel up too often, you also don’t want to let the tank go dry and find yourself in an emergency, broken down on the side of the motorway. 

After being pulled to safety by the tow truck, from that day on, you will always make sure your fuel tank is filled to the brim so you never have that experience again. 

This is not unlike what happens to most of us when we dabble with extended fasting (e.g., OMAD, ADF, multi-day fasting etc.). 

While we think more deprivation is better, we don’t account for our survival instincts intervening to ensure that we eat more than we need to, just in case we subject ourselves to another extended fast. 

Studies in rats who press a button to get food show that, when food is consistently available, they will only press the button when they need food.  However, when the food supply is inconsistent — when the button doesn’t yield food every time they press it — they go into a frenzy of button pressing, whether they need food or not, to account for the unreliable food availability. 

This is not unlike how we behave when scrolling Instagram, Facebook or Twitter.  If every post was what we wanted the first time, we would quickly be satisfied, put down our phones, and do something more productive. 

But when we see a great post, we get a dopamine hit, followed by a dopamine deficit that drives us to keep scrolling until we find something we love, like that first post.  We end up scrolling for way longer than we needed to, living in the hope of getting the same satisfaction as we did from that first hit. 

To address this, Data-Driven Fasting uses your blood sugar as a fuel gauge to empower you to know precisely when and what you need to eat.  Once your body learns that it will get what it needs when it needs it, Lizzy goes back to sleep, content there is no emergency. 

Why Fasting Fails for So Many

Many people fast for days but still aren’t lean.  It’s not that hard to do a multi-day fast, especially if you carry a lot of stored body fat. 

You may have seen people claiming to feel fantastic and bragging to everyone on Facebook about their high ketone levels after days of not eating.  However, you’ve also likely seen others complaining about lack of progress as their weight yo-yos up and down. They lose and regain the same few pounds repeatedly, with worsening body composition, often with fat gain and loss of precious muscle.  

Many fasting programs promote the idea that you can build your ‘fasting muscle’ with more willpower and progressively longer and longer fasts.  Unfortunately, many ‘by-the-window’ fasters only succeed in waking Lizzy, who responds by turning a silent or softly whimpering hunger into a screeching aria of unrequited ‘starvation’, which is unscientifically known as the ‘Godzilla response’. 

When Lizzy rampages after excessive bouts of fasting, most handlers don’t successfully tame it with grilled chicken breast and broccoli. Instead, they offer their favourite comfort foods as peace offerings.

Unfortunately, emergency comfort foods include highly processed, energy-dense, nutrient-poor foods like cakes, chips, peanut butter and ice cream that quickly undo your fast by refilling your glucose and fat fuel tanks.

‘Any fool can fast, but only the wise man knows how to break a fast.’

George Bernard Shaw

Extended fasting advocates like to point to the benefits of extended fasting and alternate-day fasting in rodents who experience all sorts of benefits.  But keep in mind that you’re not a giant mouse in captivity. 

  • One mouse day is equivalent to approximately forty human days.  So, to be sure you get the same magical autophagy benefits that we see in rodent studies after three days, you would need to fast for 120 days!
  • The other difference is that rodents get the same rat chow day in and day out.  But free-living humans can choose to eat whatever they want when they refeed.  No matter how disciplined we think we are, what and how much will change when our blood glucose levels are low, and we feel we are starving!

Unfortunately, people who regularly fast typically get less protein and micronutrients they require to prevent cravings, achieve satiety and optimise their health.  Over time, they risk becoming skinny fat, with an increase in body fat and a decrease in muscle mass. This unfavourable exchange lowers their metabolism and worsens their metabolic health.

As shown in the survey below from our Data-Driven Fasting Facebook Group, many people report numerous challenges with popular fasting protocols.  The most common being continually losing and regaining the same weight over and over.  When we saw these widespread issues, we knew we had to design a more effective fasting and feasting routine to help people get the results they were hoping for. 

The bottom line is that there is nothing magical about fasting that eliminates your need for nutrients from your food.  Lizzy will always work to ensure you get the amino acids, minerals, vitamins and energy your body requires, regardless of how much willpower you try to exert with your conscious mind.

The ‘secret’ is to find a way to get just enough restriction to achieve the benefits of fasting without pushing so hard that Lizzy wakes up and undoes all your hard work.  

Small changes that lead to new sustainable habits that lead to long-term health outcomes are always better than short-term fixes that leave you rebounding, ridden with guilt because you ‘failed’ again. 

How Your Body Uses The Food You Eat   

Our bodies have adapted to store and use a wide range of fuels to maximise resilience in any context.  The fuel we use to produce energy can come from the food we have just eaten or the fat stored in our bodies.

The table below shows the relative oxidative priority of alcohol, ketones, glucose and fat in your body (adapted from Oxidative Priority, Meal Frequency, and the Energy Economy of Food and Activity: Implications for Longevity, Obesity, and Cardiometabolic Disease by Cronise et al., 2017). 

Some fuels are more challenging to convert into usable energy than others, and the losses are higher.  This is known by several names, including,

While these distinctions are typically ignored in our simplistic discussion of ‘calories in vs calories out’, they profoundly affect how our bodies use the food we eat, how much we eat, and how much of it we store as fat.

While we continuously burn a mixture of available fuels, our body prioritises the use of fuels that it can’t store very much of. 

  • Any energy available from alcohol, like from a glass of wine, will be used first. 
  • Ketones are generally only present in our blood when glucose and protein are low, so they are used as an alternative to glucose.   
  • ‘Excess protein’ is next in the oxidative priority line-up and is burned after alcohol and ketones. But remember that most of the protein we eat is used to maintain and repair numerous critical body functions, including muscle protein synthesis. As a result, we don’t typically overeat protein because it’s incredibly satiating.  Most people struggle to eat enough protein, let alone more than we need! 

So, your body’s remaining dominant fuel sources are carbs and fats. While the body likes to keep some glucose in its bloodstream, having too much reduces the amount of fat it can use as fuel from either your diet or your body stores. 

Counterintuitively, people carrying a lot of body fat primarily burn glucose at rest. So, when we measure their respiratory quotient, or the ratio of CO2 exhaled vs the oxygen consumed, we find that they’re working overtime by trying to burn off the glucose that’s ‘backed up’ in their system.  Because of this excess glucose, they cannot access as much of the fat stored in their body. 

Because you can only store about five grams of glucose in your blood (about a teaspoon’s worth), a little dietary carbohydrate can quickly change your blood glucose levels.  This is especially true if your fat and glucose storage tanks are already full and can’t easily absorb the excess energy coming in from your diet.

While we can convert sugar to fat (through a complex and highly regulated metabolic pathway known as de novo lipogenesis), the fat in our diet is stored most of the time while our body works to burn off glucose first. Any leftover dietary fat is easily stored as adipose tissue for future use. 

It’s not that fat is a better fuel source than carbs.  While carbs are better for explosive bursts of activity and fat is more compact and better for storage, both are simply energy sources that your body can use.  Our satiety analysis indicates that reducing either carbs or fat aligns with a similar reduction in energy intake. 

Directly after eating carbs, your glucose levels quickly rise and register on your glucometer.  The key thing to understand here is that:

  • Glucose essentially ‘floats on top’ of the fat in your bloodstream and your adipose tissue
  • You must first deplete the glucose in your bloodstream before your body can access your fat stores.

Understanding the oxidative priority of various fuels is the key to successfully burning the fat and glucose in your bloodstream to finally burn the fat on your body.  

Your body’s fuel tanks are separate but interconnected; you’re always burning a mixture of glucose and fat.  As you deplete the glucose in your blood, it’s refilled from the glycogen stores in your liver and muscles (glycogen is the fancy name for the body’s stored form of glucose). As glycogen is depleted, your body turns to the fat in your blood for energy. Once glucose and fat are depleted, your body can finally use its stored fat.

You can think of your available fuels as stacked up on top of each other in your various fuel tanks, as shown below. To burn stored body fat, you must first deplete the alcohol, ketones, glucose, and fat in your bloodstream and liver.  

The image below shows how our blood glucose and liver glycogen stores change over time when we don’t eat. 

When we go without food, we deplete our blood glucose and draw down our liver glycogen.  Rather than encouraging you to fast harder and for longer, Data-Driven Fasting teaches you to fast smarter by delaying your meals just long enough to allow your blood glucose to drop below what is normal for you. 

This technique fosters sustainable, long-term progress towards your goals without pitting Lizzy against your conscious brain in a colossal battle over appetite control and perceived starvation. 

Instead, your body gets the nutrients it needs while glucose is progressively drained from your liver and blood, and your body turns to stored fat for fuel without triggering the all-too-common binge response resulting from extended fasting protocols. It’s a win-win for you and Lizzy!

As shown in the diagram below, most have our blood glucose tanks (blood and liver) filled to the brim.  This is not just because we are consuming too many carbohydrates.  It’s simply because all of our downstream fuel tanks are also full.  So, the energy effectively ‘backs up’ in our system. Hence, we see elevated blood glucose. 

When we wait a little longer to eat, we allow our body to use the glucose in our blood and then the glycogen stored in our liver.  Then, so long as we’re not eating excess dietary fat, we can access the fat most of us want to lose in our blood and body. 

For more detail, see Oxidative Priority: The Key to Unlocking Your Body Fat Stores.

Your Personal Fat Threshold

Our bodies store each respective fuel in varying quantities and use them in different ways. Body fat is your largest fuel tank. However, it can still become full and overflow. 

For reasons we don’t yet fully understand but are undoubtedly linked to biological and lifestyle factors (i.e., ethnicity, diet, inflammation, activity levels, and biological age), some people reach their Personal Fat Threshold at lower body fat levels than others.  

As a result, most people develop Type 2 Diabetes after gaining significant excess body fat.  However, others are diagnosed with type 2 diabetes while still relatively lean.

You may have heard the term ‘TOFI’ (Thin on the Outside, Fat on the Inside) used to describe people who carry their fat subcutaneously in the adipose tissue under their skin, like the guy on the left in the image below.  In contrast, others store excess fat inside and around their organs as ‘visceral’ fat, like the guy on the right.

Body fat acts like a sponge, soaking up the excess energy.  But just as a sponge can only absorb so much water, there is a limit to how much energy your body fat can hold before it overflows into other places it doesn’t belong (like your liver, pancreas, heart etc.). 

The amount of fat your body can comfortably store on the ‘outside’ of your body (i.e., your adipose tissue) is known as your ‘Personal Fat Threshold’. Once your body exceeds its Personal Fat Threshold, blood glucose levels start to rise as excess energy ‘backs up’ into your bloodstream, measured as elevated glucose levels, ketones, and free fatty acids. 

If stored energy levels continue to rise, visceral fat is deposited in and around your vital organs. While external fat stored as ‘muffin tops’ or ‘jelly bellies’ makes us cringe and reach for the latest pop-culture diet book, it’s our internal and invisible visceral fat that’s the most dangerous to our health.

For more detail, see Personal Fat Threshold Model of Insulin Resistance, Diabetes and Obesity.

Why Are Blood Glucose and Insulin So Important?

Maintaining healthy blood insulin is a big deal. When someone exceeds their Personal Fat Threshold, they risk developing Type 2 Diabetes and all the other diseases related to energy toxicity and metabolic syndrome. 

You may have heard that elevated insulin and blood glucose levels correlate with many burgeoning modern diseases, including:

However, the key thing to note here is that insulin and blood sugars aren’t the fundamental problems.  The real issue is not insulin toxicity but rather energy toxicity.  

The main action of insulin in your body is to stop all your stored energy from flowing into your bloodstream at once.  The more energy you have in storage, the more insulin your body needs to produce to hold it back. 

Once you learn to eat in a way that allows you to lower your glucose and body fat sustainably, your body will no longer need to produce as much insulin. 

For more details, see What Does Insulin Do in Your Body?

Why Its More Important to Manage Your Basal Insulin Than Your Bolus Insulin

Unfortunately, confusion and misunderstanding abound regarding the role of insulin in our bodies. Optimising our blood glucose, insulin, and body fat is not as simple as reducing our intake of carbohydrates to achieve more stable blood sugar levels. 

Insulin is a powerful hormone secreted by the pancreas.  Its most well-known role is to facilitate the movement of glucose from the bloodstream into your cells, to either be used as energy or stored away. The graph below from the Food Insulin Index Data shows how different foods raise our insulin levels after eating (postprandial).

Notice that pure glucose (black line) quickly drives insulin up, then returns to baseline after two hours. In contrast, foods like milk (containing a combination of fat and carbs) have a small initial spike but keep insulin levels elevated beyond the two-hour mark.

The more significant but often overlooked role of insulin is to function as a dam, holding back your stored energy while dietary energy comes in through your mouth.  

Monitoring insulin dosing of people with Type 1 Diabetes using insulin pumps gives us fascinating insight into the actual magnitude of ‘basal insulin’, which is required to stop your body from disintegrating — regardless of whether or not you are eating. In contrast, bolus insulin refers to the increase in insulin levels after eating.

In people on a standard Western diet, basal insulin makes up about half their daily insulin dose. However, basal insulin can be 80-90% of the daily insulin requirement for people adhering to a low-carb diet.  

A recent study of people with Type 1 Diabetes showed that when insulin wasn’t taken:

  • dietary glucose raised blood sugar in the first three hours or so, while
  • dietary fat initially lowered blood glucose in the short term but caused a significant rise after three hours. 

So, rather than focusing on carbs vs fat or fasting for days at a time, you need to find a sustainable way to reduce the amount of energy coming in from your food to allow your body to reduce the amount of energy you’re holding in storage and thus reduce your insulin levels across the whole day.

Because the amount your blood glucose rises after meals is closely related to what you eat, many people think managing their blood glucose levels after meals is their end goal. They mistakenly believe that super-stable, flat-line blood sugars will lead to improved metabolic health and fat loss.

Unfortunately, this misguided thinking leads some to swap carbs for more dietary fat and less protein.  This often results in a nutrient-poor, low-satiety diet that drives the pancreas to increase basal insulin levels and thus total insulin across the day.  

Simply swapping carbs for fat to pursue flat-line blood sugars and lower insulin is a bit like measuring the volume of water in the ocean by measuring the height of the waves at the beach.  

The real solution is to reduce the area under the curve of your insulin and glucose levels throughout the entire day, not just after you eat!  As shown in the image below, dietary carbohydrate governs the short-term rise in glucose, but dietary fat prevents your blood sugar from dropping for longer. 

The only way to get your blood sugars to drop below what is typical for you and access your stored energy is to progressively dial back the energy from fat and carbs in your diet and wait to eat until your body needs more fuel. 

Data-Driven Fasting uses the insights from your blood sugars to guide you to fine-tune when, what and how much you eat.  Before long, you learn to select higher-satiety foods that empower you to manage your appetite, enabling you to eat less and use stored energy for fuel. 

Once you solve the energy toxicity problem (i.e., excess stored energy), insulin toxicity and all the other downstream issues related to your metabolic health will look after themselves. 

What Happens to Glucose and Fat When We Eat? 

In a recent study (Hall et al., 2020), NIH researchers fed participants a 75% fat or a 75% carbohydrate diet for two weeks. They continually tracked blood glucose and tested free fatty acids in the participants’ blood after meals. 

The chart below shows how free fatty acids change after a low-fat meal (plant-based low fat – green line) vs a high-fat meal (animal-based low carb – red line).  Fat in the blood decreases more after a high-carb meal as the liver (controlled by insulin) slows the process of ‘lipolysis’ (the release of stored fat) until all incoming dietary energy is exhausted.  Once our bodies clear the carbs, stored fat is again released into the bloodstream. 

The following chart from the same study shows that after eating a high-carb meal (plant-based low fat – green line), blood glucose levels rose for about an hour and then fell back towards the baseline, while a low-carb, high-fat meal (animal-based low carb – red line) elicited a much flatter glucose response.  Interestingly, participants lost slightly more weight on the low-fat diet, despite their higher glucose and insulin levels. 

Unfortunately, dietary advice promoted by some keto advocates (i.e., reducing carbs and protein and increasing dietary fat) only manages the symptoms by stabilising blood glucose after meals; it won’t help you lose body fat or reverse insulin resistance.

As shown in the chart below from our analysis of people using Data-Driven Fasting, there is no correlation between a smaller blood glucose rise and a healthier waist-to-height ratio. So, while overfilling your glucose fuel tank with more dietary carbohydrates than your body requires is not a great idea, switching carbs for fat to achieve more stable blood sugars doesn’t help address the root cause.

The charts below show that body fat (assessed by the Body Mass Index or BMI), insulin, and blood glucose have a strong positive correlation. Therefore, the higher your body fat, the higher your fasting blood glucose and insulin across the day is likely to be.

So, the only meaningful way to reduce your insulin and fasting blood glucose levels and reverse Type-2 Diabetes is to reduce the amount of stored body fat you are carrying.

If you’re interested in learning more about this, see:

How To Use Your Blood Glucose Monitor to Lose Weight

When you don’t eat for a while, your body begins to use up the fuel available in your bloodstream.

As these supplies are depleted, your liver releases glucose to maintain stable blood sugars. As glycogen stores are exhausted, your body uses a process known as ‘gluconeogenesis’ to convert protein and even fat to glucose to refill your liver.  This critical process ensures that you always have some glucose available for explosive activity if required!

When your glycogen stores are depleted—but not entirely exhausted—your blood glucose starts dropping, and you finally begin pulling energy from stored body fat. Now, it takes less insulin to ‘hold’ your fat in storage. Well done, you! 

Whether you’re eating a high-fat or a high-carb diet, the key to burning stored body fat is having blood glucose levels return below your baseline before eating again.

How To Use Your Blood Sugar Meter as A Fuel Gauge

Wouldn’t it be great if there was a simple but precise fuel gauge for your body that could be used to tell if you:

  • needed to eat (refuel) now,
  • are craving those yummy leftovers in the fridge just because you know they’re there,
  • are reaching for food to soothe your emotions or relieve boredom, or
  • are only eating out of habit (because it’s ‘breakfast time’).

A blood glucose meter is as close as it gets to having a fuel gauge to instantly help you understand if your hunger is real.  

Unlike an Ouija Board, your glucometer never lies.  It can honestly be your new BFF if fat loss and healthier metabolic biomarkers are your long-term goals.

Maintaining blood glucose levels in the healthy, non-diabetic range is crucial to your overall metabolic health.  However, to date, our analysis of hundreds of people who have used Data-Driven Fasting shows that:

  • many people who have some experience with fasting, low-carb, or keto diets have very stable blood glucose already, and
  • manipulating your diet to achieve even more stable blood glucose does not necessarily lead to more fat loss or improved metabolic health.

To lose fat, you need to manage your blood glucose level before you eat. With Data-Driven Fasting, you will learn to use a glucose meter as a fuel gauge to lose fat without pushing your body too hard. 

Data-Driven Fasting uses your personalised blood glucose as a ‘trigger’. When you feel hungry and think about eating, you simply check your blood glucose to validate your hunger and see if you need to refuel. 

  • If your blood glucose is above your trigger, simply wait a little longer until it drops below this point. 
  • But if you’re starving and still above your trigger, you can focus on meals with protein and nutrients with less energy from fat and carbs because you know you currently have plenty of fuel in your bloodstream.  

Yes, it’s that simple!

Waiting until your blood glucose drops below your trigger ensures that your fasting routine achieves a long-term negative energy balance by using the energy in the bloodstream.

As a result, you gain all the benefits of fasting, like increased insulin sensitivity, improved blood glucose levels, weight loss, fat loss, and autophagy, without waking your survival instincts and triggering an unhealthy binge-restrict cycle.

Hunger Training: How to Lose Weight Using Your Blood Sugar as A Fuel Gauge

We designed Data-Driven Fasting to help you fine-tune your eating routine and find the minimum effective dose of fasting required to get the desired results.

Data-Driven Fasting is founded on the belief that you must first deplete both the glucose and fat in your bloodstream before depleting your stored body fat. You make this magic happen by measuring your blood glucose levels and confirming they’ve dropped below your trigger before you eat.

Although there’s nothing wrong with going 24 or 36 hours (i.e., skipping a whole day) without food, you’ll sacrifice the benefits of fasting if you make poor food choices when you eat again.

While some people believe that you can eat whatever you want, so long as you do it in a specific “window”, the reality is WHAT you eat when you refuel is critical to ensuring that you get the nutrients you need in the long term.  If you find yourself reaching for ice cream, cake, peanut butter or pizza after your fast, chances are you’d benefit by being a little less ambitious next time.

The Research Behind Hunger Training

We use a process known as ‘Hunger Trainingto ensure that the time you spend fasting doesn’t awaken your reptilian instincts and lead to poor food choices when you eat again. 

Hunger Training’ is an exciting approach with some fantastic outcomes in recent studies.

In her 2012 book, The Glucometer, Angela Ross recommended simply delaying eating if your blood glucose exceeds 5.0 mmol/L or 90 mg/dL.

Note: mmol/L are the metric units for blood sugar, while mg/dL are the imperial units used in the USA. To convert mg/dL to mmol/L, divide by 18.

A 2016 study from the University of Otago in New Zealand (Adherence to hunger training using blood glucose monitoring) found hunger training extremely effective, with obese people losing 1.5 kg on average over two weeks. Notably, the study also found it was more effective for people to have a personalised blood glucose trigger rather than simply reaching ‘optimal’ blood glucose levels before eating. 

In the subsequent study, published in 2017 by the same group (The Effect of Different Types of Monitoring Strategies on Weight Loss: A Randomized Controlled Trial), lead researchers tested hunger training against:

  • daily weighing,
  • calorie tracking with MyFitnessPal, and 
  • counselling sessions.

Hunger training using a personalised blood glucose target was the only scenario where people lost weight.  Everyone else gained weight!

People did OK when they simply tracked their weight, which appears to have made them more aware of their eating.  However, the best outcomes were achieved by study participants who used Hunger Training with their pre-meal blood glucose levels to validate their hunger signals and verify their actual need for food. 

Counterintuitively, participants using the MyFitnessPal app saw the most significant increase in weight of the four approaches tested.  

It seems that people lose touch with their true hunger signals when they outsource their satiety to a ‘smartphone’ app.  The study also found that depression, anxiety, and stress all worsened for participants who used MyFitnessPal.

Tracking blood glucose is empowering.  It provides immediate feedback on whether you need to eat now or wait a little longer.  Validating your need for food based on your blood glucose gives you a greater sense of control and empowerment.  But most importantly, hunger training allows you to reacquaint yourself with your healthy hunger signals. 

When you see high blood glucose numbers, you can immediately think back to your last meal and understand how your unique metabolism responds. You quickly learn which meals keep your blood glucose higher for longer and learn to avoid them in the future.  Conversely, you also learn which meals keep you fuller for longer and allow your blood glucose to return below your trigger sooner. 

This sets you up for long-term success once you reach maintenance.  Participants in various studies and our Data-Driven Fasting Challenges find they can reasonably accurately predict their blood glucose based on their hunger cues, particularly as their blood glucose starts to decrease to healthy levels.

Hunger Training enables us to retrain our understanding of hunger based on our body’s actual need for fuel, and eventually without the need to be guided by our blood glucose meter.

Why Did We Create Data-Driven Fasting?

While this research is fascinating, we realised that some improvements needed to be made.  So, we created a comprehensive system for sustainable weight loss and long-term maintenance, with several improvements to previous methods, as detailed below.

  • Correctly identifying your initial pre-meal blood glucose trigger is critical to the effectiveness of the Hunger Training process.  In Data-Driven Fasting, we use your average blood glucose before you eat — calculated based on three days of baselining — to establish your personalised trigger. 
  • When you move into the Hunger Training phase, you only need to let your blood sugar drop a little lower than your current average (rather than meeting some arbitrary target). 
  • As you start to delay your meals a little, you will progressively drain your stored energy.  Before long, you will find it easier to reach your initial trigger as your body adapts and you deplete your excess energy stores. 
  • To ensure you continue to make progress, the DDF app updates your trigger based on the average of your past seven days of tracking. Continually updating your target ensures you continue to move toward your goals, but not at such a fast clip that you wake your reptilian instincts and end up in a rebound binge.
  • During the first week of Data-Driven Fasting, you will learn how your blood glucose responds to the food you eat.  
  • Once you have achieved your goal, you can decrease the frequency of tracking to a level you find sustainable while still using your weight and blood sugar as a guide to prevent weight regain.


9 thoughts on “Data-Driven Fasting: How to Lose Weight and Reverse Type 2 Diabetes Without Tracking Your Food”

  1. Hi,

    I can’t join the challenge because I don’t do FB, but I am very interested in your program. I think there is an app, can I still get that? I don’t see the information about that.


  2. Hi! I’ve heard great reviews about DDD and heard you speak on a Podcast. I’m concerned since IF hasn’t really worked well for me – on and off 9 months. I do have hypothyroid (TSH 4.9), low Vitamin D levels (28) and other health markers are currently out of whack for me.

    Concerned this won’t work for me either – can you still help me?

    • lots of things tend to fall into line once you focus on lowering your premeal blood sugars and lose some weight. we’re loving seeing the results of all the people in the DDF challenges.

  3. Hi- I have been intermittent fasting for about 6 weeks. Can I “baseline”, or should I not be already fasting in order to do that. I am losing weight, but I have pushed myself to go from 16/8 to 18/6 and find that I am constantly eating in the smaller window.


    • in baselining you test when you feel hungry enough to eat (without watching the clock). bingeing during the ‘window’ is a common problem.

  4. Marty,

    I’ve been tearing through your work on this blog. Very compelling stuff here!! It closely matches my own opinions/questions/concerns about fasting, the keto diet, and this new fad of “the more fat the better”. Something about that hasn’t been sitting right with me lately, even though I’m a fan of fasting/keto and have seen results from it. Everything clicked when I read this article. It really is about energy in vs energy out… but nothing like what the mainstream says with their BS ‘calorie’ theory. It honestly makes as much sense as trying to measure our food in wattage. But I digress.

    I am much like you in the sense that I’ve always thought there had to be a mechanistic approach to fasting, and now I’ve found it, so thank you for that! Most every ‘diet’ is far too rigid to work for a significant majority of people. That’s the beauty of DDF: it’s ANTI rigid. And with the addition of analyzing blood glucose to confirm sugar responses and levels, almost all of the important guesswork is gone! Amazing.



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