This article is debunking the calories don't matter myth

Debunking the “calories don’t matter” myth

Saying calories don’t matter, seems to be the buzz phrase lately.

You may have heard; weight loss isn’t about calories. But hormones, food quality, meal timings or carbohydrates and insulin.

The thing with such claims is, they may have a grain of truth to them. But, they are disempowering and unhelpful. They leave people more confused and jumping from fad to fad.

Calories do matter. But it doesn’t mean all the other things don’t matter either.

Calorie counting isn’t the same as your bodies calorie balance. As great a tool as it is, most people do it wrong.

So, this post is going to explain why these claims are misconstrued, where these are right and where to go moving forward.

Calories are the bricks of our being

Every study shows, that the only determinant of body weight is calorie balance. (1)

Energy intake that exceeds energy expenditure is the main driver of weight gain. The quality of the diet may exert its effect on energy balance through complex hormonal and neurological pathways that influence satiety and possibly through other mechanisms.

(Romieu, et al 2013)

This extract above stated calories matters most. But is also stated the quality of your diet influences the number of calories eaten. So, a healthier diet will cause weight loss, because you eat fewer calories because you’re less hungry.

So, you don’t lose weight by eating healthy, but eating healthy makes you more full. You then eat less, thus eating fewer calories, which leads to weight loss.

Think of a building, the only way to build it is with bricks and other raw materials. If you want to put an extension on the building you need more bricks. The building can’t make itself bigger without more bricks. Though we are not buildings, it’s the simplest way for me to explain this concept.

So, the only way to lose weight is to eat fewer calories than what you burn, over a period of time. And the only way to gain body weight is to eat more calories than we burn over a sustained period of time.

People have lost weight following all kinds of crazy diets. The only thing these diets have in common was that they were lower in calories. For instance, you could eat nothing but McDonald’s and still lose weight.

John Cisna in America did this. This science teacher wanted to prove to his students that weight loss is only about calories. He ate McDonald’s every day for 6 months and lost 56 lbs.

Before anyone gets mad, I’m not suggesting you do this. You’ll get super hungry and you’ll miss out on a lot of vital nutrients. The amount of salt you’d get through, won’t be good either.

“A calorie isn’t a calorie” myth

Another counterargument the calories don’t matter advocates will state is, “a calorie isn’t a calorie”. Or that there are good and bad calories.

To the first point, I understand the premise. Some foods are more nutritious than others. But a calorie is still a calorie. That’s like saying a “mile isn’t a mile”.
10 Miles on sand is the same distance as 10 miles on grass. Like distance, calories are a unit of measurement.

Though the composition of the calories may be different it doesn’t change the amount.

Another argument is that 1000 calories of cake is different from 1000 calories of lettuce. That’s true, the lettuce is harder to eat, will have more volume and

As for the cake, you won’t be full, you could eat more and all that sugar won’t do your teeth any good. But this doesn’t change the number of calories. It’s like comparing a tonne of bricks and a tonne of feathers. Both are still a tonne.

Put 2 groups of people in a lab, give them the same number of calories of cake or lettuce; their weight changes would be the same. It’s only in free-living conditions, where the quality of calories influence how much you eat. So it is still calories that matter.

Another claim is, that only eating junk, but counting calories is unhealthy. First off, no scientist that has ever spoken about calories has told people this is what they should do. This is another straw-man argument. Doing that would be dumb.

Second of all when people have lost weight from only eating junk (to prove a point), their health still tends to improve.

A nutrition teacher ate Twinkies every day to prove calories matter. He also ate Oreo’s and Doritos too. He did also eat some vegetables, a multivitamin and protein powder too. But the majority of what he ate was junk.

The anti-calorie people will say, if the food quality is bad, your health would get worse. But this is what happened:

Haub’s “bad” cholesterol, or LDL, dropped 20 percent and his “good” cholesterol, or HDL, increased by 20 percent. He reduced the level of triglycerides, which are a form of fat, by 39 percent.

Food quality does matter. But calorie calories still matter. Heart disease is a great cause of death, weight loss is one of the most effective ways to reduce that risk.

If someone is obese and at risk of a lot of health complications, their priority is losing weight. Not eating organic avocado and kale smoothies with unicorn milk.

This is what he had to say about the whole ordeal:

“These foods are consumed by lots of people. It may be an issue of portion size and moderation rather than total removal. I just think it’s unrealistic to expect people to totally drop these foods for vegetables and fruits. It may be healthy, but not realistic.”

There you go, I’m not saying to copy this, please don’t. Unfortunately though, these days we need to take things to the extreme to get people’s attention.

“Calorie counting doesn’t work”

This is another reason people believe calories don’t matter.

The thing is, counting calories on your phone, is not the same as your bodies energy balance.

First off, when you use a calorie calculator, including mine, this is an estimate. Unless you’re hooked up in a lab, there’s no way to tell for certain how many calories you burn. Second, the number of calories you burn in a day is always changing, it’s never the same, it’s a moving target.

Then there is the input part and that’s riddled with problems. First off, it is true that the calorie labels of foods can be off by 20% either way. (2) But over a period of time, that should level itself out.

Then there’s the inaccuracy of people’s input. Most people don’t weigh what they eat, they rely on cups and spoons, which is inaccurate.
Going to restaurants is going to be a game of estimation. On Myfitnesspal one food will have 100’s of variations, which will all differ in calories.

Then there are raw and cooked foods which have different weights, affecting calories.

Most people start off with their calories too low. Do you know what happens then? You hate your life so much, you end up binging during the weekend. And then wonder why you didn’t lose weight.

As humans, we are the masters of lying to ourselves. We all underestimate how much we eat. One of my favourite studies shows registered dietitians also underestimate food intake. (3) If the gatekeepers of nutrition, can’t estimate 100%, how do the rest of us expect to be any more accurate?

We don’t register our licks, tastes and bites. People do it with peanut butter or drinking milk from the carton. It’s hundreds of calories eaten without realising. Just because you didn’t count them on your phone, doesn’t mean your body hasn’t counted them.

Counting calories is just a tool, to reduce your calorie intake. It’s nothing more. Evidence does show, when people self-monitor, they do keep off more weight. (4)

I’m not saying you have to count calories forever, to reduce calories, but it may help. I’ve written about how to count calories properly, so you don’t make all these mistakes.

I think the main reason people don’t like calorie counting is that it puts the responsibility back on them. So these gurus will say it’s not calories, it’s your hormones, it makes you feel good and like it’s not your responsibility. But sometimes admitting your own fault can be very freeing and empowering.

Reasons people say “calories don’t matter”

I really don’t like insulting other peoples methods or ideas. So for each diet where the proponent says calories don’t matter, I’m going to cut them a bit of slack and show the positives of the diet and how it works.

Insulin hypothesis

The belief is that when you eat carbs, your insulin increases, which is true. Insulin increases, as it’s used to transfer the blood sugar into your muscles and liver. (5)

But, proponents of this hypothesis say, when insulin increases the body holds onto fat. So, they claim it doesn’t matter if you eat fewer calories than you burn, your body still stores fat.

It’s believed, as the body is dealing with glucose, it turns off its fat-storing ability.

There are a few reasons this is wrong:

  • Protein also raises insulin, but protein is very effective when looking to lose fat (6,7)
  • People in the Mediterranean, Asia and Africa tend to eat very carb rich diets, but their obesity rate is lower (7,8,9)

But I do want to give this hypothesis credit too:

Elevated insulin levels tend to increase hunger and a desire for less healthy foods. What happens when someone is hungry and wants to eat more palatable foods? Yes, you guessed it, they eat more calories. The insulin model shows that people are likely to increase calories when insulin increases. (10)

Keto/low carb

I’ve written a full article about Keto. But I will outline how Keto elicits weight and fat loss.

Keto is a low carb high-fat diet. A lot of proponents say calories don’t matter on Keto because Keto lowers levels of insulin.

The thing is, people who do Keto do lose a lot of weight, without counting a single calorie. But remember energy balance and calories have existed long before Myfitnesspal has.

This is what happens when people do Keto:

  • Cut out an entire group of macronutrients (carbohydrates), people cut a lot of calories
  • Lose a lot of water weight, because you lose glycogen weight (about 5-6 lbs of water) (11)
  • Cut out all high-calorie junk food (most junk food is a combination of fat and carbohydrates)
  • No sugar (sugar contains a lot of calories and is not satiating)
  • Some eat more protein so feel fuller (12)
  • Replace carbohydrates with vegetables (More filling and fewer calories)
  • Easy diet to follow
  • Insulin levels are stable, so less likely to be as hungry (eat fewer calories)

Something else I have noticed, a lot of peoples carb servings are insane. On the packet, it will tell you how much is a good serving size. But a lot of people will have 2-3x the recommended serving. So by cutting that out you might save 1000’s of calories per day.

So Keto works and it can work well. But the reason it works is that it’s getting you to eat fewer calories.


I’ve already said, if someone says ‘calories don’t matter, you need to manipulate your hormones’, run for the hills. I still stand by that, but… I will give some credit first.

Different hormones affect hunger, satiety, the amount we move and many other variables. In fact, there’s evidence to say some are genetic.

The main appetite hormones are:

  • Leptin
  • Ghrelin


When Leptin increases in your body, hunger does too. So in times of hunger, your leptin levels will decrease.


When Ghrelin increases, hunger increases. So in times of hunger, your Ghrelin levels will increase.

The amount of Ghrelin and Leptin in your system is dependent on your genetics. There’s not much you can do, other than accept it.

So your hormones, do play a role in the weight you gain and lose. But the only reason they play a role is that they influence the number of calories you eat. (12)

Eating clean

Another claim is, ‘calories don’t matter because you need to eat clean or the right foods’. The premise is, instead of thinking about calories if you eat healthier foods you lose weight.

This works well when your original diet consists of fast food and alcohol. Then you change to lots of vegetables, lean proteins, fruit and whole grains. Your calorie intake is going to drop. Thus you lose a lot of weight without counting calories.

Unprocessed foods, contain a lot of fibre and combined with a high protein diet, you’re going to be very full.

A 500 calorie cheeseburger, is far less filling, than 500 calories of steamed chicken and vegetables. When I go to McDonald’s I order 2 cheeseburgers as 1 is not filling enough for me. But there’s no way I’d eat 1000 calories of chicken and veg, in one sitting.

This is why it’s important to base your diet on low energy-dense foods. It also helps to understand how the satiety index makes dieting easier.

Another reason is; you cut out anything that is delicious. Ultra-processed foods are tasty. These are foods, which have the perfect combinations of fat, carbs, sugar and salt. These set off our dopamine receptors in our brains, prompting us to eat more. (13)

Remember from an evolution perspective, this was an amazing tool. Our bodies want us to eat as much as possible, so these foods would have made sure we had eaten enough, so we could survive. But now these foods are everywhere.

There are few problems with eating clean. Labelling foods as good and bad can lead to disordered eating behaviours. (14)

Two, what are you going to do when you lose weight, eat clean forever? Are you going to pass up on all social events, where there are delicious foods? Trust me, all that food is going to be very seductive and you’ll struggle to pass on by.

Eating clean can lead to certain deficiencies too, depending on what’s cut out of the diet. And when some people incorporate tasty foods back into their diet, it’s known for some people to feel sick.

High protein

This is something, I actually do when I want to lose weight. Instead of focusing on calories, I make sure each meal has a solid amount of protein. 20-40g works for most people and doing that 3-6 times per day, will do the trick.

The thing with protein, unlike carbs and fat, it’s almost impossible to accidentally eat too much protein. Your body requires more calories to digest protein, which means you burn slightly more calories with a high protein diet. (15) Something I talk about more in my article, discussing how many calories you burn at rest.

Also, protein is the most satiating macronutrient.

Protein also stimulates certain hormones, which help regulate appetite. These hormones include Cholecystokinin, Ghrelin, Peptide YY, and Glucagon. (16)

Another reason protein can impact someone’s body is by changing the composition. Some people will start weight training, eat more protein and notice their scale weight hasn’t changed. But they look stronger and firmer. Thus say calories don’t matter. What happened is a body recomposition. Whilst calories matter, for changing your weight. If you want to look better and be stronger, protein is super important. (17)

Fasting/Meal timing

Another claim is instead of focusing on calories, it’s better to focus on meal timing or fasting.

One claim is eating after let’s say 6 pm, means your body is going to store the extra food as fat.

The thing is, fasting and not eating at night, both work. The reason is, I’m sure you’ve guessed it by now. Eating fewer calories.

Let’s take skipping breakfast or doing a 16:8 fast. A lot of people will have sugary cereal for breakfast. So by skipping breakfast that you cut 500-800 calories out of your diet each day.

As for not eating late at night, this is quite straightforward. During the day we are busy and food is not usually on most of our minds. But, come night time, 10 pm you’re on the sofa watching Netflix or Youtube. Eating at night doesn’t turn food into fat, it’s another way to cut 1000 calories out of your diet. That’s why a lot of competitive bodybuilders and athletes go to bed early when cutting weight. It’s one of the easiest ways to lose weight.

Metabolic adaptation

Last but not least, metabolic adaptation. The calories don’t matter proponents claim, dropping your calories for too long prevents weight loss. As again there is some truth to this, but it’s not because calories don’t matter. There are other physiological reasons.

  • Weight loss
  • Reduction movement
  • Increase appetite

Weight loss

When you lose weight. You weigh less, so burn fewer calories. This is one reason why peoples weight loss stalls. You might start losing weight on 2000 calories, soon that will be your maintenance number. As you get smaller, you’re going to need to consume less to keep losing more weight.

Reduction in movement

This is where your body moves less. When you lose weight, your body is trying to fight back. Remember in evolutionary terms losing weight would have been a bad thing. Our bodies want to get fat, to survive the famine, which is never going to happen. So one way the body will preserve calories is by making you move less.

So, it’s important to keep up movement when losing weight. Hence why people suggest getting a step tracker and hitting a certain number of daily steps. (18)

Increase appetite

As mentioned earlier, when dieting, your appetite is going to increase. Your hormones are going to do what they can to make you eat more to survive. Yes, I know there isn’t a famine on the way, but your body doesn’t know that.

To further combat these, read my post about weight loss plateaus.

Why I dislike this saying

The term “calories don’t matter” is damaging. I get it, it gets more clicks and views as a headline. But it’s misleading.

Whatever method is used to lose weight will involve calorie reduction. By misleading people and not telling them the truth, they are more likely to fall from fad to fad. It’s best, to be honest from the start. If you want to follow a certain diet that helps you reduce your calories, that’s fine. But lying to people is not cool.

I know it’s easier to say it’s not calories as it takes away personal responsibility. But were all adults here. As I said it’s not your fault, your body wants to hold as much fat as possible, it’s how most of us are wired. But with the food environment, we live in today, there’s no need.

So remember calories matter, whether you count them or not. Food quality also matters, but that doesn’t mean we need to be calorie deniers.

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