WHAT to Eat [Data Driven Fasting FAQ Part 5]

Data-Driven Fasting initially 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 gives you the go ahead to refuel.  But eventually, WHAT you eat will become the limiting factor on your health quest.

Understanding how the food you eat affects your blood sugars can be helpful to dial in your food choices.  By giving your body precisely WHAT it needs WHEN it needs it, you can increase satiety, get off the blood sugar rollercoaster and deplete the excess fuel in your system, lose unwanted body fat and eat again sooner! 

This section of the DDF FAQs details how you can use the insights from your blood sugar to dial in the WHAT to eat side of the equation. 

5.1 Can You Eat Whatever You Want With DDF?

We don’t care what foods you eat… but your body does!

Measuring your pre- and post-meal glucose levels gives you powerful insights.  You can imagine you are playing the detective in a mystery game as you try to understand what foods and meals work best for you.

Your goal is to find a shortlist of foods and meals that you enjoy that will also allow you to reach your trigger sooner and stay off the blood sugar rollercoaster. 

You can note in the DDF app which meals and foods work for your body and those that don’t.   

To help you find your shortlist of foods and meals, you can reflect on your blood sugars after each meal:

  1. Sharp rise (more than 30 mg/dL or 1.6 mmol/L) and rapid blood glucose drop.
    1. High carb, low-fat foods that raise your blood sugar quickly are not necessarily bad, especially if they fall again quickly (i.e., a small area under the curve glucose response).   
    1. But if the ‘BG rollercoaster’ leaves you tired and ravenous once your blood sugar comes crashing down below your trigger, reducing these foods might be a good idea.  You can save them for times when your blood sugar is significantly below your trigger to bring it back up quickly without resorting to energy-dense carb+fat comfort foods. 
  2. Slow rise (more than 30 mg/dL or 1.6 mmol/L) and no significant fall.
    1. Foods that raise your blood sugars and keep them elevated for a long time tend to be a combination of fat and carbs. 
    1. These foods will keep your blood sugars and insulin elevated for a long time. As a result, you will not reach your trigger again for many hours and will use less of your stored energy.  
    1. These foods are not ideal for fat loss or improving your metabolic health and should be limited or avoided. 
  3. Slight rise (less than 30 mg/dL or 1.6 mmol/L) followed by a steady blood glucose drop over the next few hours.  
    1. Foods with less fat and carbs and more protein and fibre tend to provide greater satiety per calorie and allow our blood sugars to remain lower and more stable. 
    1. Add this food to your shortlist of foods that you can use regularly.  They will provide greater satiety per calorie and allow you to eat more regularly while still losing weight. 
  4. Blood glucose falls after you eat!
    1. Higher protein % meals will often cause blood glucose levels to drop after you eat them. 
    1. These foods provide the protein your body requires with minimal energy from fat and/or carbs and maximum satiety per calorie. 
    1. These foods are a great way to “hack” your blood sugars in the morning when you feel hungry, but your blood sugar is elevated due to dawn phenomenon.   

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 throughout the day.  Trying to limit how much you eat through the day, especially protein, tends to leave most people at risk of overeating at night. 

Do what you can to ensure your first meal is ‘hearty’ with plenty of protein (e.g. steak and eggs, not a Bulletproof Coffee or a croissant).  You could try eating a robust breakfast when you feel hungry (even if your blood glucose is slightly above your trigger) and a small lunch or skip lunch it to have dinner with the family if and when your blood glucose drops. 

Or maybe you have coffee — black, or with just a dash of milk or cream — and eat a larger meal in the middle of the day followed by a moderately sized family dinner after work.  Unlike fixed meal plans, the possibilities are endless.  You can be flexible to fit around YOUR schedule.

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

For more detail, see Does More Protein at Breakfast Help You Lose Weight?

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 trigger but are still not losing weight, you’re likely still loading a lot of calories from fat into fewer meals.

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 you’re effectively 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 Lizzy stays asleep and doesn’t step in and undo 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.  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.

Our satiety analysis of data from Optimisers shows that foods and meals that contain a higher percentage of protein are tough to overeat.  People who get a higher protein % (by dialling back energy from carbs and fat and prioritising protein) experience greater satiety per calorie and more effortless weight loss.

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, a high protein:energy ratio or a Protein Sparing Modified Fast.

It’s much easier to consume a lot of energy in your meals if they contain a lot of carbs and fat with less protein and fibre. 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

As shown in the chart below, more energy from fat and processed carbohydrates (and less protein) corresponds to a higher energy intake.   

Sadly, many people who fast choose to refuel on foods with a higher percentage of energy from fat, believing eating ‘fat to satietywill lead to body fat loss.  Unfortunately, our data analysis indicates 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 progressively dial back the fat in your diet. 

You can learn more about the process we guide people through to dial in their macronutrients to align with their goals in our Macros Masterclass here.  

5.4 Plan What You Will Eat Before You’re Hungry

When we’re ravenous, we always gravitate to what is quick and easy.  So, it’s important to plan what you will eat before you get hungry for the best results.

If you test and decide to delay your next meal, take a moment to imagine what you will have when you eat next.  

Because you are not fasting for days at a time, you will be less likely to impulsively congratulate yourself with a pizza or a doughnut because you think you’ve ‘earned it’! 

Plan to eat nutrient-dense foods with plenty of protein to maximise satiety to avoid having to wait too long to eat. You can also reflect on what you ate that is keeping your blood glucose elevated for so long. 

Any diet that works over the long term tends to supply adequate protein while minimising easily accessible energy from fat or carbs. When eating, your goal should be to get adequate protein with fewer carbs to drain your blood glucose stores and less fat to allow your body to use your body fat stores. 

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 food that is energy-dense and nutrient-poor, your body will crave 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 in our Optimising Nutrition Community platform here.

If your blood glucose is still elevated, we recommend the Blood Glucose & Fat Loss food list. However, if your blood glucose is relatively stable, 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 by quelling hunger and cravings due to nutrient deficiencies and supplying adequate protein to prevent muscle loss.
High Protein:Energy RatioUse this if you want to attack your body fat aggressively without losing muscle by maximising satiety. 

5.6 Will Coffee “Break My Fast”?

Many people 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 (and you don’t need to test your blood glucose), so long as you’re not adding hundreds of calories worth of milk, butter, cream, sugar, or MCT oil.   

While there is plenty of debate over whether coffee or artificial sweeteners will break your fast and whether water alone is more optimal, you need to find the balance between optimal and sustainable for you.  Many people find themselves with headaches if they suddenly slash their caffeine intake. So, if you want to reduce your caffeine intake, it’s best to scale back slowly.

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. In fact, bodybuilders often use caffeine as a ‘fat burner’. However, if you’re not sleeping because you are drinking too much coffee too late in the day, you should stop earlier in the day or cut back. 

Some people who test their blood glucose in the morning around their regular cuppa see their blood glucose rise. However, it’s difficult to discern whether this is due to regular morning circadian rhythm effects like when your body releases cortisol, adrenaline, and stored liver glycogen to boot up your system for the day, or if it’s the coffee itself. 

If you really want to find out if coffee is spiking your blood glucose, you could test your sugars before and after you consume caffeinated coffee, decaffeinated coffee, and water at the same time of the day.  If you see a similar response at the same time regardless of what you drank, it’s likely the Dawn Phenomenon rather than the coffee. 

However, given that the goal of Data-Driven Fasting is to achieve a long-term negative energy balance, the slight rise in glucose around your coffee should not be of concern as long as your coffee contains minimal energy.  Any change in insulin or blood sugar that occurs in the morning around your coffee is not going to impact your fat loss goals if it doesn’t contain a significant amount of energy that will stop your body using your stored body fat.

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

For more detail, see Will Coffee Break My Fast? A Complete Guide on Coffee and How It Affects You.

5.7 Electrolytes and Fasting

An adequate intake of electrolytes like sodium, potassium, magnesium, and calcium is critical, especially when eating less and losing weight.  One of the many functions of insulin is to help your kidneys recycle electrolytes in your body. When insulin levels decrease, you 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. Often 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 not only helpful, but it’s also critical to ensure you are getting essential minerals other than sodium. 

If you’re interested in supplementing these harder-to-find minerals, we have created an Optimised Electrolyte Mix with the optimal amounts and ratios of sodium, potassium, and magnesium that many people have found helpful. 

One problem with mineral salts is that you can quickly reach your ‘gut tolerance’, or the amount your body can physically absorb at a given time, 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 determine whether you need more minerals in your typical diet and determine which foods and meals you need more of, you can try our Free 7-Day Nutrient Clarity Challenge.

5.8 How Much Protein Do I Need?

Protein requirements depend on your lean mass and 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 closer to 1.8 g/kg LBM or ideally 2.2 g/kg LBM.  These higher levels of dietary protein help prevent muscle loss during rapid weight loss and support muscle growth and recovery after training.

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

You can use our macro calculator to see how much protein you need, and you can 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 for men and 25% for women). 

height (cm)height (inches)female protein (g)male protein (g)
150595676
155616081
160636486
165656892
170677298
1756977103
1807181109
1857386116
1907590122
1957795128
20079100135
20581105142
21083110149

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%.  Once you reach your goal weight, you can bring back some energy from fat and carbs. 

If you need some more guidance after the Data-Driven Fasting Challenge, you can try out Macros Masterclass, which will guide you to tweak your macros to help you sustainably move towards your goals. 

5.9 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, and fat raises insulin and blood glucose over the long term. 

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

Insulin regulates the release of stored energy from the liver while energy is coming in from our mouth. Someone with Type-1 Diabetes will essentially disintegrate as all of their stored energy flows into their bloodstream if they do not inject insulin. However, for someone who has a functioning pancreas, the insulin produced by their pancreas is largely a function of the amount of fat in their body or 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 subsequently require less insulin across the day. 

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

Many people in our Macros Masterclass find that they are already getting the protein they need; they just need to slowly dial back their energy from fat and/or carbs while making an effort to prioritise protein. 

5.10 How Should I Break A Fast?

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

However, multi-day fasts are not the goal of Data-Driven Fasting. We simply 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 refuel. 

It’s always ideal to ensure your first meal of the day has plenty of nutrients and protein.  If you still need it later, you can top up with some extra energy.   Many people find their blood sugars are lower later in the day, so protein with a little more carbs is often ideal in the afternoon while focusing on protein, which comes with fat, is ideal at your first meal. 

5.11 Can I Drink Alcohol While Fasting?

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

  • Due to oxidative priority, your body must burn off the alcohol before glucose and fat, so you will down-regulate the release of glucose (and fat) into your bloodstream until your body clears the alcohol it cannot store. 
  • You should also be aware that alcohol will have a greater impact if you have no other food on board. 
  • We tend to make poor 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 (for reference, fat contains nine calories per gram and carbs and protein yield less than four calories per gram). 
  • Alcohol often comes with plenty of carbs and other yummy things that are easy to overdo. 
  • While alcohol initially knocks you out, you don’t get into REM sleep as quickly because your metabolic rate is elevated to burn off the high-octane energy from alcohol. So not only will you feel dehydrated and have a hangover, but you won’t get a great rest either. 
  • Alcohol is similar to sugar, refined grains, or oils in the sense that it is effectively empty calories.  Alcohol contains lots of energy with very few nutrients, so it won’t help you on your quest to maximise nutrient density

5.12 Should I Eat Less Protein If I Have Diabetes?

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

More dietary protein will be converted to glucose if you are insulin-resistant and have elevated blood glucose (via gluconeogenesis).  The net result is that you will have less protein available for muscle protein synthesis.

To make up for the protein lost to glucose, your appetite will increase, and you will consume extra energy to get the protein you need.  For this reason, it is crucial for people with Type-2 Diabetes or any degree of insulin resistance to prioritise dietary protein.  

5.12 Aren’t Meal Choices Important Too?

WHAT you eat is arguably more important than WHEN you eat. Food choices also play a big role in how long your blood glucose takes 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 calorie, so you will likely consume more calories.
  • Meals with more fast-digesting non-fibre carbohydrates will initially raise your blood glucose. But they may also return to below baseline sooner because they are hard to overeat and are burned off more quickly.
  • Foods that contain both fat and carbs with low protein will fill both your fat and glucose fuel tanks and prompt 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 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. During Hunger Training, it’s important that you reflect on which meals tend to keep your blood sugars elevated for longer and identify the meals that you enjoy that allow your blood sugars to return to below baseline more quickly. 

5.13 Do I Need MCT Oil or Butter During a Fast?

No.  Adding nutrient-poor, low-satiety refined oils or fats will be counterproductive if your goal is body fat loss, insulin sensitivity, improved body composition, nutrient density optimisation, or diabetes reversal.  For reference, Bulletproof Coffee has the lowest satiety and nutrient density ranking of the thousands of recipes we have analysed. 

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), your body will use approximately 400 calories per day (100 g) of stored protein in the early stages of extended fasting. Over time, this decreases to 250 calories (60 g of protein) per day as it adapts.

While protein requirements slowly decrease during extended fasting, the amount of lean muscle mass you will use for fuel is still insignificant. If you fast for a couple of days every week, you will need to make up for protein across the week to prevent long-term loss of lean muscle.

After not eating for a while, your body increases your appetite to seek food to replenish calories and nutrients, particularly protein, to ensure your muscles don’t waste away. If you do not prioritise protein when you refuel, your appetite will step in and ensure you consume enough calories to get the protein your body needs. 

This is likely the main reason so many people lose and regain the same weight when they attempt extended fasting without paying attention to food quality.  It can be challenging to get adequate protein without excess energy in the long term when extended fasting forces us to gravitate to energy-dense food.  Regardless of how long you choose to fast, nutrient-focused refuelling (especially protein) is critical.

5.15 Does DDF Work Best with A Particular Diet (e.g. Low-Carb, Keto, Vegan, Plant-Based)

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

Foods high in starch like potatoes are hard to overeat if they are not combined with added fat (e.g. chips or cookies) that increase palatability.

  • Many people find they achieve the lowest pre-meal blood glucose on a low-fat diet with whole foods.
  • Conversely, low-carb foods cause a smaller rise in blood glucose after eating but may cause blood sugars to remain elevated for longer.  

As shown in the chart below, reducing either fat or carbohydrate in your diet will similarly impact satiety and how much you eat. 

The problem comes when we consume low protein foods combining fat and carbs together. These hyperpalatable foods tend to be easy to overeat and will keep your blood glucose and insulin levels elevated for much longer. It will then take longer for your blood glucose to drop back below your 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.  Many people find keeping their carbs for later in the day when their blood sugars are lower while prioritising protein (which tends to come with some fat) earlier in the day to be an extremely helpful strategy. 

5.16 What If I’m Above My Trigger but REALLY Hungry?

If you are above your 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 trigger, the DDF App will suggest you can eat but prioritise protein and nutrients and limit fat and carbs. 

It’s hard to go wrong if you limit fuel when you’re above your trigger and only refuel (with fat and carbs) when your blood glucose is below your trigger.

5.17  How Can I Use My Glucose to Guide How Much I Eat? 

There are many reasons we feel hungry, but out conscious brain doesn’t always understand exactly what our body requires.  But the good news is, you can use your glucose as a fuel gauge to help decipher what fuel and how much you need. 

  • If you’re hungry and your BGs are elevated, then it’s likely you don’t need carbs, but rather protein (which tends to come with some fat).  If your blood sugars are elevated, you can see this as a sign that your fuel tanks are full.  You should try to eat a smaller meal rather than an all-out feast. 
  • If you’re hungry and your blood glucose is much lower than normal for you, then it’s definitely time to eat.  Giving your body some carbs may help to quickly bring your blood sugars back up and can quickly smash your cravings. 

It’s been fascinating to see how different people with different dietary patterns and routines have different glucose patterns that can give precise data-driven insights into what to eat at different times of the day.

Low carb pattern

People who follow a lower-carb diet tend to have higher glucose in the morning and lower glucose levels in the afternoon.  As you can see in the example chart below, few post-meal glucose values are above the upper limit.  People from a lower carb or keto diet background typically don’t need to worry about dialling back their carbohydrate intake.     

Counterintuitively, higher waking glucose can be managed by dialling back fat in the evening.  Excess energy from fat can cause all your fuels to back up in your system overnight.  So, in the morning, you see a higher waking glucose and possibly even rising waking glucose throughout the morning due to dawn phenomenon. 

Rather than delaying your meals until the afternoon, it’s often ideal to prioritise protein (which typically comes with some fat) and fewer carbs in the morning.  This usually allows blood glucose to drop back down quickly so you can eat again sooner. 

In the afternoon, when blood sugars are lower, it’s ideal to swap some fat calories for carbs to bring glucose back up a little before bed (but not so much that you would boost blood glucose above the upper limit). 

Alternating between protein+fat in the AM and protein+carbs in the PM tends to allow people to stabilise their blood sugars across the day.  They can also have a more varied diet that is potentially more nutritious while staying out of the carb+fat danger zone that leads to overeating. 

Lower fat diet pattern

People on a lower-fat diet tend to see lower waking glucose and higher glucose values during the day, particularly in the afternoon, as shown in the example hourly chart below. 

The first step here is to dial back the excess carbs that are overfilling their glucose fuel tank while prioritising protein for increased satiety.  Converse to the low carb profile, people following a lower-fat diet may do better with more of their carbs in the morning when they are more insulin sensitive and less at night, particularly if they see their pre-bed values going well above their upper limit line. 

Mid-afternoon pattern

Other people, like the chart shown below, see a distinct dip mid-afternoon dip, indicating that this is the ideal time for them to have their largest meal based on their unique routine and metabolism

Balanced profile

Finally, the hourly chart shows what we believe to be a pretty ideal hourly glucose chart, with:

  • Most post-meal values under the upper limit line,
  • Lower waking glucose, and
  • Fairly similar premeal values across the day. 

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