Data-Driven Fasting: How to Use your Blood Glucose as a Fuel Gauge

Data-Driven Fasting is a first-of-its-kind, personalized approach to guide your daily eating routine using your internal fuel gauge. 

Most popular fasting approaches prescribe a strict one-size-fits-all pattern, like 18:6, 20:4, alternate day or multi-day extended fasting.  

Unfortunately, without personalization, people only learn to ignore and push through their hunger, often leading to poorer food choices and overeating when they are ‘allowed’ to eat again.

Instead of a fixed eating window, Data-Driven Fasting uses your blood glucose to make more intelligent choices about when and what to eat. 

Rather than ignoring your healthy appetite signals, Data-Driven Fasting teaches you to train your hunger so, in time, your body learns to trust that you will give it precisely what it needs when it needs it. 

The Big Secret of Data-Driven Fasting

The big secret of Data-Driven Fasting is that it’s not fasting as most people think. 

Instead, it’s more quantified mindful eating or glucose-guided eating using technology to understand your unique metabolism

While some people use a continuous glucose monitor, all you need is an accurate glucometer to validate your hunger and understand what your body needs. 

Getting Started with Data-Driven Fasting

Over the years, we have fielded many questions in our Data-Driven Fasting Challenges and documented the answers in the manual for others to benefit. 

The detail in this manual will unpack all the hows and whys around using your glucose to guide what and when to eat.  But if you want to get started now, you can:

Why We Created Data-Driven Fasting

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 the minimum effective dose of fasting without breaking.  You need to learn to stretch your body just a little, but not so much that it rebels, and you find yourself trapped in an endless restrict-binge-restrict cycle, as many sadly do. 

As with most things, more isn’t always better when it comes to fasting.  You only 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 and improves your metabolic health using your premeal blood glucose to guide your weight loss progress.  DDF guides you to 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.

Read on to learn how to use your blood glucose to guide when and what to eat! 

Your Healthy Appetite Signals Have 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 colorings, scents, and flavors that 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 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 friend told you that the best time to put fuel in your car was at 10 am on the first Saturday of the month.  

But they drive a hybrid hatchback, have a twenty-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 refueling schedule that your friend follows religiously 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 fuelling 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 fine tuning your fasting routine based on your fuel gauge (your blood glucose) than you will by filling up on someone else’s rigid 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.  So, to continue the car analogy, you’ll 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 at every opportunity to ensure 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 or multi-day fasting). 

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 panicked button pressing, whether they need food or not, to account for the unreliable food availability. 

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 returns to sleep, content that 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 fast for a few days 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, usually with worsening body composition.  That is, increasing fat gain with 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.  But, unfortunately, many ‘by-the-window’ fasters rely on their conscious willpower. 

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

A crucial part of Data-Driven Fasting is learning to give your body the nutrients it needs when you are hungry but your blood sugars are still elevated.  This ensures we avoid extreme hunger when all we want is nutrient-poor, energy-dense comfort foods. 

Is Fasting for Longer Better?

Extended fasting advocates like to point to the benefits of extended 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 benefits of autophagy that we see in rodent studies after three days, you would need to fast for 120 days!
  • Another thing to remember is that lab rats get the same chow day, regardless of how hungry or satiated they feel.  However, free-living humans can choose to eat whatever they want when they refeed.  So, no matter how disciplined you think you are, what and how much you eat will always change when you awaken your survival instincts when you allow your blood glucose level to drop below what your body is comfortable with.  

Why Are Blood Glucose and Insulin So Important?

Maintaining healthy blood glucose and 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 glucose aren’t the fundamental root cause.  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. 

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 help you understand whether your hunger is real instantly.  

Unlike an Ouija board, your glucometer never lies.  So 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, our analysis of nearly five thousand people who have used the Data-Driven Fasting app shows that:

  • Many people who have some experience with fasting, low-carb, or keto diets have very stable blood glucose already
  • 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 must manage your blood glucose level before eating. 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 personalized 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, 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 all the benefits of your voluntary deprivation 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 that 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 Training’ to 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 recommends simply delaying eating if your blood glucose is above 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 an arbitrary ‘optimal’ blood glucose level 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 the MyFitnessPal app, 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 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.  People seem to 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.  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 predict their blood glucose based on their hunger cues, particularly as their blood glucose decreases 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.

The Data-Driven Fasting System

While the research is fascinating, we realized we could make some improvements to make the process more practical and effective.  So, we created a comprehensive system for sustainable weight loss and long-term maintenance, as outlined below. 

  • Correctly identifying your initial pre-meal blood glucose trigger is critical to Hunger Training.  In Data-Driven Fasting, we use your average blood glucose before you eat — calculated based on three days of baselining — to establish your personalized 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 automatically updates your trigger based on the average of your past seven days of premeal blood glucose values.  This moving target ensures that you continue to move toward your goals, but not so fast that you wake your reptilian instincts and end up in a rebound binge.
  • Data-Driven Fasting also shows you how your food affects your unique metabolism and how to make better food choices to see your glucose drop below trigger sooner. 

Leave a Comment