Why everything you have been told about calories is WRONG

It seems simple: if you eat too many calories or don’t burn enough, you will get fat.

And if you want to lose weight, just scoop less and move more.

Unfortunately, the truth about calories isn’t nearly as simple as we’ve been led to believe, experts point out.

Professor Giles Yeo, a world-renowned geneticist from the University of Cambridge and author of Why calories don’t countexplains it best – and urges people to focus on the quality of what they’re eating, not the small number tucked away on the side of a pack.

‘We don’t eat calories; we eat food and then our body has to get the calories out,” he told MailOnline.

Human bodies are “not bonfires” that just burn all the calories equally.

For example, we absorb fewer calories by eating an orange segment than by drinking its juice – even though they contain exactly the same amount, says Professor Yeo.

‘If you drink orange juice, it has no or very little fiber in it, because we squeezed it out. And our bodies absorb the sugar pretty much within minutes.

“But when you eat an orange, you have to chew it and that takes time to digest,” says Professor Yeo.

This, experts in the field argue, is just one example of why focusing purely on calories is so misleading.

The basic concept of food as fuel – in which the body effectively takes on the role of an oven – was brought to light in the 1880s by an American chemist who wanted to know how much ‘energy’ different foods contain.

Wilber Atwater burned them to ashes and measured how much heat (or calories) each produced. That rudimentary system is still in use 150 years later.

As a result of his experiments, we now calculate total calories based on the three main components of food: fat (of which Atwater contained about 9 cal/g), protein, and carbohydrates (both 4 cal/g).

Yet the system — essentially an amalgamation of averages — ignores the intricate complexities of digestion.

Following the same logic as the body absorbing fruit juice faster than pieces, cooking also reduces the effort required for digestion.

A piece of raw celery alone is about 6 calories, he says. But if you cook it, that can quickly turn into 30.

Professor Yeo told MailOnline: ‘I didn’t add any calories to the celery – it’s just that our bodies can only get six calories from raw celery.

“If you cook it, because cooking is almost an extension of your stomach, your body has less work to do.

“Eating it allows you to take in more calories.”

For this reason, the number of calories on a label of processed or cooked foods is probably an underestimation, says Professor Yeo.

On the other hand, labels on high-protein foods can overestimate the calorie count.

Because of the work it takes to digest protein, we will only extract 70 percent of those calories, according to Professor Yeo. ‘So 30 percent of protein calories are used by our body to process protein.

‘The number of calories in proteins is 30 percent incorrect everywhere, none of the backs of the packaging take this into account.’

Another example of why calories don’t always add up is the “empty” calories, such as those in candy.

While an apple and a lollipop have the same amount of calories, the apple is clearly the healthier option, as eating too many nutritionally empty calories will quickly take its toll on your health.

These factors make calories a “blunt tool” for controlling what we eat, despite such imperfect counts being praised by gym-goers and fitness fanatics alike.

Professor Yao said, “A big part of the problem today is the quality of the food we eat.

“The biggest problem with ultra-processed foods, in my opinion, is the fact that they are inherently lower in protein and fiber because of the processing.”

He added, “Say you had to stick to 1,500 calories a day for a diet, there’s a big difference if you had 1,500 sugar versus 1,500 steak.”

“It’s better to have 1,500 calories of steak than 1,500 calories of sugar.”