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Why the Calories In vs Calories Out Principle is Not a Practical Tool for Weight Loss

Who wants to be fat? Show of hands…? Anyone? No-one…right…me neither!

Many people’s lives seem to be totally consumed with how ‘fat’ they perceive themselves to be, how much they want to get rid of that fat and what they are doing to remedy the situation.
This mental and physical battle of the bulge can have a huge impact on our happiness, health and wellbeing, our stress levels and our ability to enjoy our food and any social occasion that includes the eating of food.

No-one actually wants to be fat or overweight.
Having a bit of extra body fat can make you feel pretty crappy.
It makes it hard to find nice clothes that don’t look like they should have been maternity wear or yacht sails. It can limit your social life and make you feel less attractive to the opposite sex. It can reduce your ability to take part in spontaneous activities like a game of cricket on the beach, wrestling with your kids or chasing an escapee dog that houdinied its way out of the backyard.

Crystal & Andrew, Before and After Paleo

Being overweight can also limit your career aspirations (especially if you are female) and people are more likely to value judge you, and assume you have no self-control. Kids can be pretty mean, being a bit heavier than the other kids might have meant you were picked last for the team or were picked onwith taunts like “…you’re fat and you stink!”

Thanks to advice in mainstream media, everyone knows what they need to do to lose weight or more accurately to lose body fat.
You just have to eat less and exercise more, everyone knows this.
It comes down to simple mathematics based on the laws of thermodynamics.

…the calories we consume will either be stored, expended, or excreted. This in turn implies that any change in body weight must equal the difference between the calories we consume and the calories we expend, and thus the positive or negative energy balance. Known as the energy-balance equation, it looks like this: Change in energy stores = Energy intake – Energy expenditure”- Gary Taubes, Good Calories, Bad Calories

So, the theory goes that if you eat more calories than you burn, your body will store that extra energy in either your organs and muscle tissue (limited storage), or in your fat tissue (a virtually limitless storage).

If you eat less than you burn – or burn more than you eat – then the extra energy you need to go about your daily tasks will be sucked back out of your fat storage to make up the deficit and wahlah…you will lose weight.

There is no question that Australians (and probably New Zealanders) do eat more than what we used to 30 years ago.

…the mean energy consumption of Australian adults living in capital cities increased significantly by around 3%–4% (about 350 kJ/day) between 1983 and 1995.
An energy imbalance of 3%–4% in adults (about 350 kJ/day, equivalent to a slice of bread, or 30 minutes of sitting instead of brisk walking) would produce weight gain of about 1 kg per year”
- The Medical Journal of Australia


breads by Leo Reynolds, on Flickr

So are we hungrier now than we were 30 years ago?

Why would we eat more?
Well, from an evolutionary perspective, we were designed to overeat under certain conditions.

In the summertime when the going was good and food was abundant our ancestors would have gorged on calorie-dense food to store up some energy for when food was scarce. Insulin and leptin resistance was a useful adaptation to stockpile this extra energy into fat tissue.
In the winter or during a famine when food was scarce, body fat stores would have been burnt to make up the energy deficit.
Metabolic rate and body heat expenditure would go down and muscle efficiency would go up, along with appetite and motivation to find food.

Our ancestors survival depended on this feast famine metabolism.
Our modern day survival does not.

In our modern, industrialised world we have constant access to an abundance of food. No matter the season, we can drop into any supermarket and pick up slabs of Coke, bags of Dorrito’s, and loaves of bread or any fast food joint for a quick and tasty feed.
Part of the problem is that the food we eat today is totally out of kilter with what our ancestors would have been exposed to and even what our great grandparents would have been exposed to. They didn’t have access to food that was nearly as calorie-dense as the heavily refined, processed food that is
manufactured today.
If we compare only carbohydrate intake as an example, it would look like this:

Image used with permission from Douglas Robb of Health Habits (click to download his free ebook)
In this example, the amount of calories are taken out of the equation because the actual amount is irrelevant, the total carb calories represent 100% of the pie graph.
Note how much of the modern man pie is refined carbohydrates.

No-one actually wants to be fat or overweight, but if it was as simple as just cutting out a slice or two of bread each day then obesity would certainly not continue to be so widespread.

It’s not like we are not trying, a recent datamonitor survey found that

…the proportion of Australians who regularly make an effort to eat and drink smaller portions has increased to 46% in 2010 compared to 29% in 2009” – Australian Food News

So how is that working out for us?
Well, if you sit in any shopping center for long enough and just watch the people that walk past you, it quickly becomes clear that we are certainly not winning the battle of the bulge.

Are we just becoming gluttons that, despite our efforts, still overeat or sloths that do not exercise enough or worse yet, are we descending into both gluttony and slothfulness?

Not necessarily.

The real question that we should be asking is: Does the calories in/calories out energy-balance equation have any practical application to help us lose weight or prevent obesity?
And the answer is…no.

When any government organisation, nutritionist, personal trainer or weight-loss guru use ‘calories in vs calories out’ to advocate eating less and exercising more to lose weight, they have to make 3 assumptions:

Assumption #1:

That the only two variables that impact our body fat stores are the calories we consume and the calories we expend.

Assumption #2:

That these two variables, the calories we eat and the calories we expend, are independent of each other, meaning we can change one of these two variables while keeping the other constant. Or, change both of these variables and have our bodies play along with us and go scavenging in our fat stores to make up the extra energy we need to function day to day.

Assumption #3:

That when we make a conscious decision to reduce the calories we eat or increase our energy expenditure or both, all it takes is the willpower and discipline to stick with it as a long term weight loss strategy.

These assumptions are too simplistic and short-sighted for practical use. They do not take into account any of the other factors involved and they do not address what is biologically driving our overeating behaviour.

Although Gary Taubes (author of Good Calories, Bad Calories & Why We Get Fat) and Stephan Guyenet (Neurobiologist and blogger at Whole Health Source) have opposing ideas on the causes of obesity and the mechanisms that lead to weight gain, they both agree that in order to form a practical strategy for weight loss we have to address the ‘why?’

Why do we overeat? What is driving our increased appetites and motivation to seek out food when we clearly have an ample supply of energy in our fat mass?

When we understand this, we can also understand why tweaking our food quality will have more impact than tweaking our food quantity.

I briefly referred to the calories in vs calories out principle when I first started the Getting Your Weight Loss Ducks in a Row series. My hope is that this detour into the calories in vs calories out concept and the different theories of obesity, before we cover Duckie #2: Eat Real Food. Cut out the crap, will help to explain why the quality of the food matters just as much if not more than its caloric content.

It will also help to show that we will definitely get a better return on our investment when we direct our weight loss efforts towards strategies that reduce inflammation in our bodies and improve our hormonal signalling, as opposed to just eating less and exercising more.
These strategies include getting more quality sleep, eating quality food, managing stress, improving gut health and training sensibly.

You don’t lose weight to get healthy, you get healthy to lose weight”
- Sean Croxton, The Dark Side of Fat Loss

Take home messages:

  • Broadly speaking, on a daily basis we eat more food now than we did 30 years ago, despite trying harder to control our portion sizes.
  • Or, perhaps it is more accurate to say that we are eating food that is more calorie-dense now. So we should probably throw portion control out the window and focus more on what we are actually eating
  • If we eat more calories than we use our bodies have to stash that extra energy somewhere and we will gain weight. This is indisputable, but the real question both Gary Taubes and Stephan Guyenet pose is why? Why do we eat more?
  • Although a mathematically correct equation, the calories in calories out principle does not have any practical application for those wanting to lose weight. This is because it does not address what is biologically driving us to consume more food than we need to.
  • Our fat mass is controlled by more than just calories in vs calories out. If it was as simple as just cutting out a slice or two of bread each day then obesity would certainly not continue to be so widespread
  • One of the big differences between what we eat today and what our great grandparents would have eaten is processed foods.

Things to ponder:

  • If we don’t want to gain weight, what compels us to overeat and steadily accumulate more and more fat?

“I’m new to all this, what can I do right now?”

  • Try cutting out some foods that come in a box or a bag.
  • Try cooking more of your meals at home and taking your lunch to work with you.
  • Try and get more protein and ‘good fats’ into your meals, these send hormonal signals to the brain that say “I’m full, you can stop eating now” and also “I am still full, no need to eat more yet”
  • Try to include more foods like: chicken, beef, fish, pork, eggs, nuts, avocados, olive oil, coconut oil, coconut milk/cream.
  • Check out the Recipe Links in the right hand column for some ideas on what to cook.

Also check out this follow-up post: Debunking Calories In vs Calories Out for Weight Loss: Assumption #1


References and Further Reading & Listening


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