WHAT to eat [FAQ Part 5]

Data-Driven Fasting helps you solve the WHEN to eat side of the nutrition equation.  You can make a lot of progress just by waiting until your blood glucose fuel gauge indicates you need to refuel.  To minimise overwhelm, we recommend you focus on chasing your trigger in Hunger Training until you feel you have mastered the process. 

But eventually, WHAT you are eating becomes the limiting factor, and it can be helpful to understand how the food you eat affects your blood sugars and how to dial in your food choices to ensure you are giving your body what it needs to maximise satiety, tame the blood sugar rollercoaster and deplete the fuel in your system, so you are ready to eat again sooner. 

5.1  Can you eat whatever you want on DDF?

Absolutely.  We don’t care what foods you eat, but your body does.

By measuring your pre-meal/post-meal glucose, your body will give you clues about what to eat. You are playing a detective game trying to figure out what foods work for you.

The goal is to find up to 30 foods and 30 meals that let you get to your trigger, avoid the blood sugar rollercoaster, and that you enjoy.

So take a note of meals that worked for your body and the ones that don’t. It doesn’t mean that you need to avoid the meals, just eat them less often or less of them.

Can you imagine if, after 30 days, you have a list of foods and meals that work for YOU and not something you downloaded from the internet designed by someone else for someone else? 

To find your Personalised Optimal 30/30, you can run the following check for each meal you eat:

  1. Sharp rise (+30 mg/dL or 1.7 mmol/L) and quick fall of blood glucose -> if this “BG rollercoaster” leaves you tired and hungry quickly after the meal, then it might be a good idea to restrict that meal.
  2. Sharp rise (+30 mg/dL or 1.7 mmol/L) and no significant fall. Put this meal into a restriction category.
  3. A less than 30 mg/dL or 1.7mmol/L rise and then a steady drop of blood glucose over the next few hours, you have found one of your go-to meals.

5.2  Front-load your protein to hack your satiety!

Our data analysis shows that people who eat more protein at their first meal tend to eat a lot less across the day. 

Do what you can to make sure your first meal is “hearty” with plenty of protein (e.g. steak and eggs, not a Bulletproof Coffee or croissant).  Perhaps you could eat a big breakfast and a small lunch or skip lunch at work and have dinner with the family if/when your blood glucose drops. 

Or maybe you have coffee first up (black or with just a dash of milk or cream) and eat a large cooked meal in the middle of the day and then a moderate dinner with the family after work. 

We want you to identify the routine that suits you that allows you to move towards your goals.  Try to find a routine that works for you that allows you to eat in a controlled manner and avoid ravenous late-night hoovering of everything in the fridge. 

5.3  Why am I not losing weight?

If you are eating one or two meals a day and waiting until your blood glucose drops below Your Personalised Trigger but are still not losing weight, then it’s likely that you’re managing to simply load a LOT of calories into fewer meals. 

When fasting, what you eat is still critical!  Food quality becomes even more critical when food quantity is reduced.  Don’t underestimate your reptilian instinct’s ability to outsmart your conscious brain to keep you alive, especially when trying to starve it.  

The good news is you can tame your lizard brain by reverse-engineering your diet to give your body what it needs, so it stays asleep and doesn’t step in and make a mess of all our discipline and hard work.

If you push your body too hard, your cravings for energy-dense foods will increase to enable you to get more energy in the compressed eating window.  Some people who eat a high–fat, keto diet with plenty of body fat to lose see their waking blood glucose remain elevated while their daytime blood glucose is low and stable.  This is likely because they are filling up their fat fuel tank, so their body doesn’t need to tap into their stored body fat.

To understand if this is the case for you, it may be helpful to track your food intake for a few days in Cronometer to check the macronutrient split of the food you are eating.  Also, to check your food’s micronutrient content and find out which foods and meals you should be eating to achieve a balanced diet at a micronutrient level, we recommend our free 7-day Nutrient Optimiser Tracking Challenge.

Our analysis of data from Optimisers shows that foods and meals that contain a higher percentage of protein are tough to overeat.  People who get closer to 40% protein experience greater satiety and effortless weight loss, whereas people who are getting closer to 15% protein struggle to lose their unwanted body fat.  Some people refer to this as ‘fuel pulling’ (where you pull glucose and fat from your body rather than your food), a Low Energy Diet or a Protein Sparing Modified Fast.

It’s easy to pack a lot of energy into your meals if they contain a lot of carbs and fat with less protein.  This is the basic formula for modern junk food.  Given the opportunity, your body will always choose the low –protein, energy-dense foods that allow you to consume more energy and store more fat for the coming winter.

Sadly, many people who fast choose to refuel on foods with a higher percentage of energy from fat, believing eating ‘fat to satiety’ will lead to fat loss from their body.  Unfortunately, our data analysis indicates that this approach makes it easier to consume more energy.  If you want to use the fat on your body as fuel, you may need to moderate the fat in your diet. 

Eating fewer meals and getting less protein is not ideal in terms of satiety or achieving optimal body composition.  Before focusing on nutrient density, in our Nutritional Optimisation Masterclass, we guide people to ensure they are getting adequate protein and then trim back the energy from carbs and fat to align with their goal. 

As shown in our analysis of our series of NutriBoosters, foods with a higher percentage of protein tend to have a higher nutrient density.  Focusing on nutrient-dense foods when you eat is incredibly important, particularly if you are trying to eat fewer meals and consume less energy overall. 

5.4  Plan what you will eat before you’re hungry

It’s important to plan what you will eat before you get hungry.  If you test and decide to delay your next meal, take a moment to imagine what you will have when you eat next.  Plan to eat nutrient-dense foods with plenty of protein to maximise satiety so you won’t have to wait too long to eat.   You can also reflect on what you ate last that is keeping your blood glucose elevated. 

Any diet that works over the long term tends to have adequate protein with less easily accessible energy from fat and/or carbs.  When eating, your goal should be to get adequate protein while keeping carbs low (to drain your blood glucose stores) and keeping fat low (to allow your body fat stores to be used). 

Because you are not fasting for days at a time, you will be less likely to feel like you should congratulate yourself with a pizza or a doughnut because you think you “deserve it”. 

5.5  What should you eat after fasting? 

What you eat is just as important as when, how much or how often you eat.  If you fill up on energy-dense, nutrient-poor food, your body will be craving nutrients again sooner.  So when you eat, do whatever you can to maximise nutrient density to ensure you are getting the nutrients you need with fewer meals and less energy.

To help with this, we have developed a range of printable .pdf food lists to help you optimise your diet that you can access here.  If your blood glucose is still elevated, we recommend the blood glucose & fat loss food list.  If your blood glucose is relatively stable, then you can go straight for the fat loss food list. 

We have also created a series of NutriBooster recipe books optimised for a range of goals

The table below will help you find the right recipe book for you.  Click on the name of the book in the table to learn more.

ApproachIdeal for
Low carb & blood glucoseUse these if your blood glucose is consistently elevated (i.e. they rise more than 1.6 mmol/L or 30 mg/dL after meals).
Blood glucose and fat lossIdeal for anyone with elevated blood glucose and body fat to lose.
Fat lossIdeal for rapid fat loss with less hunger and cravings due to nutrient deficiencies and adequate protein to prevent muscle loss.
High protein:energy ratioUse this if you want to attack your body fat aggressively without losing muscle, with maximum satiety. 

5.6  Will coffee “break my fast”?

Many people using Data-Driven Fasting enjoy a coffee or tea in the morning and delay their Main Meal until later when they are hungry, and their blood glucose drops below their trigger. 

Your morning cuppa doesn’t need to count as a meal so long as you are not adding hundreds of calories worth of milk, butter, cream, sugar or MCT oil.  You don’t need to test your blood glucose before your morning coffee.     

While there is plenty of debate over whether coffee or artificial sweeteners will break your fast and water only may be more optimal, you need to find the balance between optimal and sustainable.  Many people will find themselves with headaches if they suddenly slash their caffeine intake. 

Most studies find that caffeine has a positive effect on metabolic rate and fat loss and stimulates the release of stored energy from the liver.  Bodybuilders often use caffeine as a ‘fat burner’.  However, if you’re not sleeping because you are drinking your coffee too late, you should stop earlier or cut back. 

If they test their blood glucose in the morning around their regular coffee, some people see their blood glucose rise.  However, it’s hard to discern whether this is due to regular morning circadian rhythm effects (i.e. your body releases cortisol, adrenaline and stored glucose from your liver to boot you up for the day) rather than the coffee itself. 

If you really want to find out if your coffee is spiking your blood glucose, you could test your blood glucose before and after caffeinated, decaffeinated coffee or water at the same time of the day. 

However, given that the goal of Data-Driven Fasting is to achieve a long term negative energy balance, the small rise in glucose around your coffee should not really be of concern so long as your coffee contains minimal energy, particularly if it enables you to compress your eating window in a sustainable manner. 

Rather than wondering, ‘will this break my fast’, you should really be asking, ‘will this allow me to achieve a negative energy balance that will lead to fat loss and a lower blood glucose?’

5.7  Electrolytes and fasting

Electrolytes (i.e. sodium, potassium, magnesium, etc.) are critical, especially when you are losing weight. 

One of the many functions of insulin is to help your kidneys recycle electrolytes in your body.  When insulin levels decrease, you will lose stored water in your body as well as electrolytes. 

You may feel light-headed or experience muscle cramps if you do not have adequate electrolytes on board.  Much of what we experience as “hunger” is actually a craving for minerals. 

While many people find adding mineral salt to their water, drinking bone broth (or even pickle juice) is helpful, it’s also critical to ensure you are getting all the essential minerals, not just sodium.   We have created an Optimised Electrolyte Mix with the optimal amounts and ratios of sodium, potassium and magnesium that many people have found helpful. 

The problem with mineral salts is that you can quickly reach your ‘gut tolerance’, so you still may not be able to get the amount you need from supplements.  As always, it’s ideal to obtain your nutrients (including minerals) from food. 

To find out whether you need more minerals in your typical diet (and which foods and meals you need more of), you can try our Free 7 Day Food Discovery Challenge.

5.8  How much protein do I need?

Protein requirements will depend on your lean mass and your activity level. 

While 0.8 g/kg LBM is an absolute minimum to prevent deficiency, we tend to find people do better in terms of nutrient density and satiety with 1.8 g/kg LBM or ideally 2.2 g/kg LBM.  These higher levels help to prevent loss of muscle during rapid weight loss and support muscle growth and recovery after training

In percentage terms, we find people achieve better satiety and fat loss when they slowly work up to 40% or more of their energy from protein.  However, rather than eating more high protein foods, this is achieved by getting adequate protein and dialling back easily accessible energy from both fat and carbs. 

Rather than jumping from one extreme to another, we recommend you slowly dial up the protein % of your diet.  You only really need to increase your protein % if your current way of eating is not yielding weight loss.  Once you reach your goal weight, you can bring back some energy from fat and carbs.

If you find you are not hungry, you don’t need to worry so much about your absolute protein intake (in grams) so long as your protein percentage is higher than 40%.

You can use our macro calculator to see how much protein you need and track your intake in Cronometer for a few days to see what you are getting from your current diet.   If you want to skip the calculations, the table below shows what 1.8 g/kg LBM looks like (assuming 15% BF and 25% for women).  

height (cm)height (inches)female protein (g)male protein (g)

Will ‘too much protein’ raise my insulin levels and stop me from losing fat? 

Refined carbohydrates raise insulin more over the short term, protein raises insulin over the medium term, while fat raises insulin over the longer term. 

While most people typically focus on the short-term change in insulin levels after eating, our overall insulin production across the day is more closely related to our total calorie intake and our body fat levels.  Insulin can be thought of as the ‘anti-entropy hormone’ that stops our bodies from falling apart.  The bigger we are, the more insulin we require to hold our bodies together. 

Insulin regulates the release of stored energy via our liver while we have energy coming in from our mouth.  Someone with Type 1 Diabetes will essentially disintegrate, with all their stored energy flowing into their bloodstream, if they do not inject insulin.  However, for someone who has a functioning pancreas, their insulin production will largely be proportional to their body fat levels and how much energy they need to keep in storage. 

While protein does elicit a medium-term insulin response, it is also the most satiating macronutrient.  Prioritising adequate protein allows us to eat less over the long term, reduce body fat levels and hence require less insulin across the day. 

Remember, satiety is about getting a higher percentage of protein rather than necessarily consuming more protein.  To achieve this, you can progressively dial back the energy in your diet from fat and carbs.

5.9  How should I break a fast?

Many people find they experience gut distress and diarrhea when they eat again after fasting for days at a time and have to eat particular foods to acclimatise their digestive system to eating again. 

This is not the goal of Data-Driven Fasting.  We want to optimise your day to day eating routine so you can consume high-quality, nutrient-dense food to satiety without digestive issues or bingeing when you refeed. 

It’s always ideal to lead with a nutrient-focused (including adequate protein) meal earlier in the day.  If you still find you need it later, you can top up on some extra energy (from fat and/or carbs), guided by your blood glucose levels. 

5.10  Can I drink alcohol while fasting?

Alcohol tends to decrease blood glucose.  Alcoholics often have very low HbA1cs.  However, this is not necessarily a good thing. 

  • Due to oxidative priority, your body has to burn off the alcohol before glucose and fat, so you will downregulate the release of glucose (and fat) into your bloodstream until your body clears the alcohol that it cannot store.  
  • We tend to make poorer food choices after drinking a significant amount of alcohol that will keep our blood glucose elevated for longer. 
  • At seven calories per gram, alcohol is energy-dense (compared to fat which is nine calories per gram and carbs and protein which yield four calories per gram). 
  • Alcohol often comes with plenty of carbs and other yummy things that are easy to overdo. 
  • While alcohol knocks you out, and some people think they fall asleep faster, you don’t get into REM sleep as quickly because your metabolic rate is elevated while you burn off all the high-octane energy from the alcohol.  So, not only will you feel dehydrated and have a hangover, you won’t have slept well either. 
  • Alcohol is effectively empty calories (similar to sugar, refined grains, or oils).  It contains lots of energy with very few nutrients, so it won’t help you on your quest to maximise nutrient density

5.11  Should I eat less protein if I have diabetes?

Some people mistakenly try to achieve perfectly flatline blood glucose by reducing both their protein and carbohydrates.  Unfortunately, this often ends in overeating low-satiety, nutrient-poor, high-fat foods, which in turn leads to increased energy intake, weight gain and insulin resistance!  

If you are insulin resistant or have elevated blood glucose, there will be more dietary protein ‘lost’ in the conversion to glucose via gluconeogenesis and hence not available for muscle protein synthesis.   To make up for the protein that has been lost to glucose, your appetite will increase, and you will consume extra energy to get the protein you need. 

Hence, rather than avoiding protein, it is crucial for people with Type 2 Diabetes or any degree of insulin resistance to emphasise a higher protein percentage (by reducing easily accessible energy from carbohydrates and fat) until they can lose body fat and reduce their blood glucose levels to become more insulin sensitive. 

5.12  Aren’t meal choices important too?

Yes.  What you eat is arguably more important than WHEN you eat.  But food choices also play a big role in how long your blood glucose will take to return to baseline. 

  • High-fat foods and meals will keep your blood glucose stable after meals.  However, high-fat foods and meals tend to provide fewer nutrients and satiety per caloriev, so you will likely consume more calories.
  • Meals with more fast-digesting non-fibre carbohydrates will raise your blood glucose quickly, but they may also return to below baseline more quickly.
  • Foods that contain both fat and carbs with low protein will fill both your fat and glucose fuel tanks and allow you to eat more.  Hence, they keep your blood glucose elevated for longer. 
  • Foods with a higher percentage of protein are harder to overeat and won’t raise your blood glucose significantly (in fact, they may reduce them).  Your blood glucose will return to below target more quickly.

Data-Driven Fasting works best when paired with nutrient-dense, high satiety foods.  During Hunger Training, it’s crucial that you reflect on which meals tend to keep your blood sugars elevated for longer and identify the meals that you enjoy that tend to allow your blood sugars to return to below baseline more quickly. 

5.13  Do I need MCT oil or butter during a fast (aka “Fat Fasting”)?

No.  Adding nutrient-poor, low satiety refined oils or fats will be counterproductive if your goal is fat loss from your body, insulin sensitivity, improved body composition, nutrient density or diabetes reversal. 

5.14  Do I need protein when I fast?

As shown in the chart below from Quantitative Physiology of Human Starvation: Adaptations of Energy Expenditure, Macronutrient Metabolism and Body Composition (Hall, 2012), in the early stages of extended fasting, your body will use approximately 400 calories per day (100 g) of stored protein. Over time, this decreases to 250 calories (60 g of protein) per day.

While protein requirements do tend to decrease during extended fasting, the amount you still use is not insignificant.  If you fast for a couple of days every week, you will need to make up for that protein across the week to prevent loss of lean muscle over the long term.

When you refeed, your body will raise your appetite to seek out food to replenish calories and nutrients, particularly protein.  So, if you do not prioritise protein when you refeed, your appetite will step in and ensure you consume enough calories to get the protein your body needs. 

This is likely the main reason that so many people find themselves losing and regaining the same weight when they attempt extended fasting without attention to food quality.  Our analysis suggests that around two meals a day with an emphasis on protein at the first meal is ideal for long term weight loss without losing lean mass.  It can be challenging to get adequate protein over the long term without excess energy when we gravitate to energy-dense food when we refeed after fasting for more extended periods. 

Regardless of how long you chose to fast, nutrient focused refeeding (especially protein) is critical to your long-term success.

5.15  Does DDF work best with a particular diet (e.g. low carb, keto, vegan, plant-based)

DDF will work with a low-carb or low-fat diet.  Low-fat foods may raise your blood glucose quickly, but they will also return to baseline more rapidly than with a high-fat meal. 

Foods high in starch, such as potatoes, are hard to overeat so long as they are not combined with added fat.  Some people find that they get the lowest premeal blood glucose on a low-fat diet with whole foods.  Conversely, low-carb foods will cause a smaller rise in your blood glucose after eating but may stay elevated for longer.  

The problem comes when we consume foods that are a combination of fat and carbs together (with low protein).  These foods tend to be easy to overeat (hyperpalatable) and will keep your blood glucose and insulin levels elevated for much longer, so it will take longer for your blood glucose to drop back below Your Personalised Trigger. 

If you wanted to mix it up and get more variety in your diet, you could alternate between low-carb and low-fat meals (particularly if you are insulin sensitive and do not see a significant rise in glucose after you eat).  Allowing your blood glucose to return to below baseline before you eat ensures that you are not filling both your fat and glucose fuel tanks at the same time. 

5.16  What if I’m above my trigger but REALLY hungry?

If you are above Your Personalised Trigger, it’s ideal to wait.  You know your body has enough fuel on board.  But if you are REALLY hungry and just above Your Personalised Trigger, it’s OK to eat, but you should prioritise nutrients (i.e. leaner meats and seafood with non-starchy vegetables), given you know you already have plenty of fuel onboard.  It’s hard to go wrong if you limit fuel when you’re above your trigger and only refuel (with fat and carbs) when you’re below your trigger.

DDF Index