Why “Diets” Fail: Part II

The Science Corner

Part II – Dieting Paradox: Eat Less Burn Less, Eat More Burn More

Last instalment we introduced you to the concept of Adaptive Thermogenesis or how your body responds to different energy intakes.

The take home messages of Adaptive Thermogenesis were:

In a Negative Energy Balance – your body will adapt to burn LESS energy

In a Positive Energy Balance – your body will adapt to burn MORE energy

This instalment we peel another layer off and see what exactly is being affected, which aspects of your energy out are getting influenced the most, and how you can use this to your advantage to EAT MORE and BURN MORE.

We’ll also learn how these adaptations can work AGAINST YOU and prevent you from achieving your fat loss goals.

So, if you’ve ever gone on a diet and been disheartened by the amount – or lack thereof – of fat loss, this is super important for you to get to know.

To understand what is happening and what is the best way to combat it, we need to expand a little bit on what we have learned so far. The reason we need to go this step further is because Adaptive Thermogenesis affects some of these in different ways.

Key Important Sciency Thing Number 1

As we learned last week, Adaptive Thermogenesis refers to changes in how much energy you burn each day, namely:

  • The Resting Component of your energy expenditure
  • The Non Resting Component of your energy expenditure

The Resting component, REE, of your energy expenditure can actually be further broken down in to two parts

  1. Resting Energy Expenditure (REE we talked about last week)
  2. Diet Induced Thermogenesis (DIT)

Again, don’t be confused by the heavy science terms and acronyms!! All this means is simply the following:

  • Your body burns energy while at rest.
  • And it burns energy when you eat.

These are the only two ways your body can burn energy when you aren’t doing activity.

You’ve probably heard me talk about diet induced thermogenesis in the past in another way, Thermic Effect of Feeding. Or, another way to say it, It Takes Energy to Make Energy. This is basically the energy cost that goes in to digesting, extracting, etc energy out of the foods you eat.

The Non Resting component, nREE, can be broken down in to:

  1. Exercise Activity Thermogenesis (EAT)
  2. Non Exercise Activity Thermogenesis (NEAT)

Exercise Activity Thermogenesis is pretty straight forward, it’s just the energy burned during exercise. NEAT is pretty much any and all of the rest of the activity you do each day that isn’t classified as “exercise”.

Realistically your body doesn’t distinguish between what you would call “Excercise” and any other activity. Do you really think your body is thinking that walk you took along the river is exercise, compared to you walking around the shops and saying, no, no, no that one was EAT, this one is NEAT?…No! For all intents and purposes for these definitions, think of any activity that is of a higher level of movement and intensity as Exercise and anything that is lower intensity as incidental day to day activity as NEAT. As rubbish as I think these definitions are, they’re important to the story later.

So, if it’s all starting to get a little confusing, let me bring it back to basics real quick.

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It’s actually pretty simple and straightforward. Just kind of gets made to sound complicated.

Why do you need to know this? Well, you don’t really…But, it is important to understand because how each of these respond to a negative and positive energy balance is slightly different. So it’s important to make the distinction now instead of later.

See! Now you have a full understanding of everything that makes up your “energy out’ part of the equation when you look at “energy in / energy out”

But again, if you think fat loss is simply a matter of “energy in / energy out” we still haven’t finished our discussion yet, so read on.

Now let’s look more closely at exactly how Adaptive Thermogenesis affects your weight loss efforts by affecting these factors. As you are going to find out, calculating your “calorie deficit” starts to become a little more complicated…

Key Important Sciency Thing Number 2

What Happens In Calorie Restriction

When you cut down your calories and create a Negative Energy Balance, this affects ALL of the energy out side of the equation, but mainly has an affect on your Resting Energy Expenditure.

That means your Resting Energy Expenditure (REE), your Diet Induced Thermogenesis (DIT) AND your Activity Energy Expenditure (AEE) are ALL influenced by this process.

You are essentially burning LESS energy for doing the SAME things!! And you burn less when you are doing nothing!

This has been reproduced again and again in numerous studies over the years – decades even…

“Sixty-five years ago, the Minnesota Starvation Experiment was the first quantitative description of AT in humans [5••]. Since then, AT has been reproduced in experimental and clinical studies on weight loss. AT varied between 100 and 500 kcal/day, it is observed in lean as well as overweight subjects. AT is independent of the weight loss strategy.” (Muller, et al, 2016)

100-500 calories a day!! That’s huge!! That’s how much a difference in your energy deficit this can make, even for just doing the same things! Have you ever tried cutting 500 calories from your diet before? That’s 1/3 of some peoples current calorie intake, even more for others already on a Jenny Craig 1200 calorie weight loss plan.

Also, this was independent of weight loss strategy! INDEPENDENT of weight loss strategy. Meaning you can’t escape this. It doesn’t matter what diet cult you subscribe to, if you are cutting down the overall calories, this WILL AFFECT YOU TOO.

There are some methods which circumvent this a little more than others, but we will discuss these in the future instalments.

So, pretty much it doesn’t matter who you are, if you cut your calories too much, or for too long, your body will actually slow down how much energy it burns. This could even cost you hundreds of calories worth of energy each day!!!

What Happens In Overfeeding

In the converse of this, the stupid thing is, when you overeat, your weight gain is often LESS than what is really expected from the amount of “calories” you have overconsumed.

Here’s where the effects of Adaptive Thermogenesis behave a little differently by influencing only specific factors. When you over consume your energy, this mainly affects the Non Resting Energy Expenditure.

“With continuous overfeeding, body energy stored was 60–75 % of excess energy leaving the rest for an increase in EE which was explained by obligatory costs (e.g. for gaining body protein, increased cost of walking, etc.” (Muller, et al, 2016)

Again, this is HUGE!!!! 25-40% of the excess energy consumed…pfffff…gone. NOT stored as fat. It was put as an increased cost of exercise. They burned MORE energy during activity.

If you’ve ever seen your PT or insta hero post pictures of their Nutella pancakes, and you think “how can they get away with it” it’s because their metabolism really does kick up a gear and their body will actually BURN MORE energy during their next workout to compensate for it.

I’ll say it again. Their bodies BURN MORE ENERGY than usual during their next workouts

Key part here though, there is different with a short term over feed as opposed to long term, or continuous overfeeding.

What Happens When Your Metabolism is Broken?

Why is it sometimes then some people just sniff a piece of chocolate and they gain 5kg of fat? Or why is it that people that are carrying a little more weight are dieting so hard and so strict but they don’t seem to lose any?

If you want to know how powerful Adaptive Thermogenesis can be, it can “explain about 50% of the less than expected weight loss in obese people that go on a diet” (Muller, et al, 2016).

Read that last sentence again, and then think of all the times you have tried to go on any sort of diet you thought was a failure, or didn’t get the results you were expecting.

It again, all comes back to what we are talking about above, but the body has lost it’s ability to adjust correctly to the same stimuli.

If you have overfed yourself for too long, been dieting for too long, or too hard by dropping calories too much, you will find that some of these processes have become a little…messed up…They don’t respond the way you want them too. It’s not like they’re broken beyond repair (remember it always adapts and finds a balance point) it just might take a little extra time and careful planning to get there.

What Happens When It Is Controlled?

“During controlled overfeeding, the non-resting component of EE, i.e. EAT increases at unchanged NEAT” (Muller, et al, 2016)

And this is a really important point. This means the energy you burn during exercise actually increases when you do controlled overfeeding. But the controlled overfeeding won’t change your NEAT.

You will burn MORE energy than usual when you exercise. But the energy you burn during your other normal daily activities still stays the same. So, by definition, exercise is not classified as just a regular walk. But something a bit more strenuous.

You picking up what I’m putting down here?? For the slower ones who haven’t figured it out yet…There should be periods of controlled overfeeding, AND…YOU HAVE TO FREAKING EXERCISE when you do it.

You will actually burn MORE calories if you do this. You can’t just keep trying to cut your calories more and more and more to lose weight!!!!

When you eat more, you will burn more during exercise. If you want to see this in action, give a child some lollies and see what happens…You eat more, your body will have energy to do more. And it will burn more while doing this activity. Don’t starve yourself and try to train hard. Again, think of your PT and his stupid visits to Cowch almost weekly for dessert…

All of this sounds dumb so far though right?

If you want to lose weight, you have to go in to a calorie restriction. But if you go in to a calorie restriction you won’t burn as much energy, and you want to burn MORE energy in order to create this deficit. But you burn more when you eat more, but you can’t eat more because you are trying to create this deficit…so, what the heck do you do?

This is the cycle so many people find themselves in…They want to lose weight, so they restrict calories. But then this weight loss stalls. So then they restrict calories. But the weight loss stalls. Soon they’re at the point where they’re eating next to nothing, but the scales aren’t moving and they’re still a loooong way off of their dream figure.

So What GIVES???!!!

The picture is slowly starting to form though.

  • You need periods of controlled calorie restriction (no drastic calorie drops or detox)
  • Controlled and planned segments of refeeding or “diet breaks”.
  • You need to make sure you are doing this in conjunction with a well planned exercise program.

See. Simple. Easy. But there’s a bit more to this picture still…

Next instalment you will go even deeper and understand what’s really happening inside your body to control this Adaptive Thermogenesis and how you can further manipulate it to make it work FOR you NOT AGAINST you.


The energy you burn at rest is divided up in to your resting metabolism and also the energy you burn from eating food.

The energy you burn through activity is divided up in to the energy cost of exercise and the energy from any other activity.

When you under consume your calories, your body will BURN LESS energy for doing the same things. This affects ALL of the energy out side of the equation.

When you over consume your calories, your body will BURN MORE energy when you exercise.

Controlled periods of overfeeding will actually INCREASE the amount of energy your burn during exercise and less of this excess will be stored.

But you must do this in conjunction with exercise.

Müller MJ, Enderle J, Bosy-Westphal A. Changes in Energy Expenditure with Weight Gain and Weight Loss in Humans. Curr Obes Rep. 2016;5(4):413-423. doi:10.1007/s13679-016-0237-4