It’s official – you cannot out run a bad diet, your biology won’t let you

Finally the proof that the advice to move more doesn’t lead to weight loss, in fact it does the opposite if you combine vigorous exercise with severe calorie restriction.

Click to listen to the audio…

Why move more and eat less is not a weight loss recipe

You know you shouldn’t………

  • Have another piece of cake
  • Have another latte
  • Have whatever [your favourite calorie loaded snack]

For me, it’s another spoon of peanut butter.  Eish !  It is my nemesis.  In and of itself, it is probably ok.  The macros are balanced.  And a teaspoon here and there, as a pick me up is fine.  But half the bottle is not Kosher.   It creates  SERIOUS tummy wobbles


And justify our indiscretions with…..

I’ll burn it off

At the gym.  More often than not, you do it the other way round………….YOU DESERVE IT, because you just completed an hour spin class.

Now this kind of thinking is perilous, because it is hard to do calorie maths post work out.

But, even if you do the maths well, it won’t help.

Seriously, we’ve been fed a lie….

You cannot out run a bad diet.  EVER !



This is what an enormous group of researchers, there were more than 80 researchers, including a dead dude, involved in establishing  THIS FACT.  The brains behind the operation where two guys, they set out to actually DO THE MATHS, borrowing data from everyone else.

a group of scientists all holding a test tube

NOTE : By borrowing data  from their colleagues, they were able to amass “energy data” from 1 754 people, from around the world, living normal lives and this allowed them to “flatten out the noise” and reach this conclusion.

Energy budgets in the wild

To start off, they did a little thinking about how energy works in animals.   If you were a bird, a bear of a bat…………. you would need energy to

  • Move
  • Grow
  • Reproduce
  • Keep vigilant
  • Keep warm and keep cool
  • Run your metabolism

Now how much you would need, would vary, but as a rule of thumb, an animal living in the wild would have an energy budget that looks something like this.

the break down of an wild animal's energy budget

NOTE :  In the middle there, they have squeezed in an energy use, that might not at first glance be intuitive.  TEF stands for “the thermic effect of food”,  basically  it is the energy it takes to process food.  Pulling apart that piece of steak requires energy………………think of it as the cost of doing business.

Energy budgets in humans

Next they did the same thing for adult humans – who thanks to “domestication” don’t have quite as many drains on the fiscus

In the case of  adult humans :

  • The utility company’s energy is more often and not, used to thermoregulate.
  • Adults are done growing
  • Reproduction is only an energy drain for a brief window of time.
  • And the need to go out and hunt for food has largely been obliterated.

So a typical adult human budget might look like this.  The activity level will be impacted by lifestyle and occupation.

the energy budget of a typical adult human

Having set the parameters up, the team put their thinking hats on, to contemplate what would happen if a sedentary human, decided it was time to GET ACTIVE and joined the gym.

Moving  more

Now if you’re wondering, what the hell is there to think about…..

Active energy expenditure would increase.

Yes it would, but what impact would this have on the overall energy budget.

Think money not energy

If your household expenses suddenly increase and the situation is not MANAGED, you end up with more month than money.

The money situation has to be managed.

You might tighten your belt or get another job.

What does the body do ?

It’s not unreasonable to expect the body to manage the situation to BALANCE THE BUDGET, but it’s not something we TYPICALLY DO.

The default thinking is  the belief that the body, DOES NOTHING !

NOTE : It’s hard to know what is happening on an individual level, because everyone’s BEE is a little different, just because our biology is always a little different, but if we look at enough human’s energy budgets, it is possible to figure it out.  That’s what these researchers did.

The default thinking

Assuming NOTHING,  allows  health gurus, to  confidently tell us, that if you want to lose weight, all “we” need to do, is MOVE MORE.  Actually,  to be fair, they do often put a caveat onto that statement……

Eat less and Move more.

NOTE :  Unfortunately the brain does the exact opposite of this……… moving more encourages us to EAT MORE. You can learn more about this here.

It’s a thought experiment

But this is a thought experiment, so we won’t  consider the mind games.  If we just simply  assume the body doesn’t react, the additive model, would give us an  energy budget, that  would look like this.

the energy budget in the additive model of move more

The AEE would increase, so would the TEE , but the AEE would have no impact on the BEE.

If we looked at the picture on a population level, in which individuals have different BEEs, thanks to genetics and environment, the AEE would not be related to BEE.   Basically,  Jo the couch potato, would have a lower total energy expenditure, than Mike the weekend warrior, but they could still have a similar BEE.

Aren’t we at risk of bankruptcy ?

Now just writing that down and looking at it, might have created an uneasy feeling for you.  It did for me……

It is a recipe for BANKRUPTCY.

At some point, the exercising machine – would run out of juice.

Odds are,  Mother Nature is too smart to allow this to happen.  But this is what a lot of us are believing……..

Actually, some of us  take this belief a step futher, believe that the more we exercise, the more of a MACHINE we become.

the energy budget in the performance model of move moreNow if this was true,  as AEE increased, TEE would go up, along with  BEE.

And at first glance, this makes sense, since 12 weeks in the gym, can make an enormous difference to how a sedentary body looks.  And a good looking body must be more efficient.

Mmm….  this looks like bankruptcy on steroids ?

Where would all that extra energy come from, if you were NOT eating MORE.  A LOT MORE ?  If there is a sudden increase in activity energy expenditure,  without the possibility of acquiring more energy by eating more, something else would have to go.

the energy budget in the compensation model of move more

The something would be the BEE.

This is what this energy budget would look like.  And the population level,  AEE increased and BEE would decrease.

So which do you think is true ?

Remember officially we don’t know, but based on our thought experiments,  I would put my money on the last scenario, wouldn’t you ?

Lean times call for lean behaviours.

Now this is where the 80 plus researchers come in…..

Mother Nature won’t let you starve to death

By combining all those data points, they were able to “see” what happens in real people.


Plot of actual human data showing AEE against BEE

Graph showing activity energy expenditure (AEE; MJ·d?1) as a function of basal energy expenditure.Copyright © 2021 Vincent Careau et al

The data matches the compensation model, ss active energy expenditure increased, basal energy expenditure decreased.

Ouch !    This  is why moving more on it’s own is not the SOLUTION to weighing less.  And moving more, while starving (severely restricting calories) is potentially counter productive, since an especially low BEE, will mean your body is capable of quite literally RUNNING ON FUMES.

But hang on a minute………

Switch off the inflammation

Actually, in some circumstances, the drop in BEE might be a boon, not a bust.  Well that’s what Herman Pontzer from Duke University surmises.

graphic showing refernce

You see, the basal energy expenditure includes the immune system.  A slightly under fuelled immune system,  might not be such a bad thing.

So the take home message………….

Move more

It’s good for you………

But don’t make the mistake of thinking you can out run other bad habits, biology won’t let you.

No worries………….

Biology does give you lots of tools to lose weight, if you want some science based tips & strategies THAT WILL WORK.  Enrol in our free weight loss E-course. Here is the link.

Energy compensation and adiposity in humans.   Curr Biol. (2021) 31(20): 4659–4666.  Vincent Careau, Lewis G Halseyet al.

Energy Constraint as a Novel Mechanism Linking Exercise and Health. PHYSIOLOGY (2018) 33: 384–393.Herman Pontzer.  

Further reading

sending your kid to bootcamp won't stop childhood obesity

Moving more won’t stop your kid from getting fat

There is no disputing this – fat kids do move a lot less than thin kids. But is looks like health gurus are muddling up cause and consequence.

caveman wiggling his toes on the couch

It’s HOW you sit, not THAT you sit, that matters

Humans like to SIT, this happens in both Western and traditional cultures, but in the jungle, there are NO COUCHES – and this makes sitting less of a health risk.

boat sinking

Become a MATADOR………… lose that weight and keep it off

When you diet to lose weight, your body often becomes a fat saving machine, causing the dreaded diet plateau. MATADOR dieting helps you overcome this

Want to discover more ways to create BETTER BODY CHEMISTRY ?