Why counting energy does not add up

Everyone knows that consuming fewer energy will assist us shed extra pounds. However most of us don’t know that what actually counts is how our our bodies use this power, as Jo Macfarlane discovers 

‘Eat fewer energy, we’re advised, and we’ll shed extra pounds. Whereas this stays true, the issue is that it’s not the complete story. The flaw is that not all energy are equal.’

On one hand, a two-finger KitKat. Within the different, a small handful of nuts. Each comprise roughly 100 energy. Which might you select when you had been attempting to shed extra pounds? Does it even matter? That’s the thorny query on the centre of the entire notion of energy – these numerical measures of power that characteristic on the dietary labels of all the pieces from tinned soup to loaves of bread. Calorie counts are a authorized requirement on pre-packaged food and drinks, designed to assist us make more healthy consuming selections and keep inside our advisable each day limits – at present 2,000 for ladies and a couple of,500 for males.

From subsequent April, due to the Authorities’s weight problems technique, many cafés, eating places and takeaways might be compelled to show calorie data relating to each food and drinks merchandise they promote. On the floor, it is smart. A lot of our most devastating ailments are linked to poor diets, and the underside line is we eat an excessive amount of. Proof exhibits that displaying calorie content material may help us to assume extra correctly about what, and the way a lot, we eat.

Eat fewer energy, we’re advised, and we’ll shed extra pounds. Whereas this stays true, the issue is that it’s not the complete story. The flaw is that not all energy are equal. However with so many diets round – from the favored Noom weight-loss app, which makes use of a site visitors gentle system to ‘rank’ meals in accordance with calorie content material, to the intermittent fasting pattern, which tells us that after we eat is simply as necessary as what we eat – it’s little marvel that we’re confused, or that round 95 per cent of diets fail.

So what does the essential science inform us? And may we actually belief the calorie counts on packaging? The reply to the latter is a agency no, in accordance with one of many nation’s main specialists on this area. Dr Giles Yeo, who’s an weight problems specialist on the College of Cambridge’s Wellcome-MRC Institute of Metabolic Science, says that whereas calorie counts are helpful, they’re not the complete story. If we solely have a look at calorie content material, we ignore not simply the supply of these energy, however the best way the physique metabolises and digests the meals we’re consuming.

The necessary query, Dr Yeo explains, is ‘not “what number of energy does this comprise?”, however “what number of energy from this could my physique use?” Most individuals don’t know that the calorie counts you see in all places are incorrect,’ he says. ‘Nobody is mendacity or making up numbers. However we don’t eat energy – we eat meals from which our physique extracts energy. The method of digestion and metabolism itself makes use of up power and energy, which varies in accordance with what you’re consuming. So it’s the quantity left over from the entire you see on the packet that issues most.’

Vegan burgers and oat milk are far much less wholesome than we predict they’re.

That is the true calorific worth of a meals – an idea referred to as ‘caloric availability’ – and also you received’t see that on any meals labels. It’s not unattainable so as to add it, Dr Yeo says, as a result of we already know the caloric availability of every of the principle elements of our meals – protein, fats and carbohydrates. When you perceive the idea, you’ll be able to see that the place our energy come from actually does matter.

A calorie of protein, for instance, whether or not from meat, fish, eggs, beans or tofu, will make you are feeling fuller than a calorie of fats or carbohydrates due to the best way it’s digested within the physique. Protein travels additional down the intestine earlier than it’s digested and absorbed. This triggers the discharge of intestine hormones which ship alerts to the mind telling us we’re full. Protein can be extra chemically advanced than fats or carbs, so it takes extra power to metabolise it. Because of this, if we eat 100 energy of protein, scientists know that our our bodies will expend roughly 30 energy processing it, leaving 70 accessible for different functions. That is partly why high-protein diets – such because the Atkins or Keto plans – work in serving to us shed extra pounds. And it’s why a handful of nuts will trump a KitKat each time, if we need to shed extra pounds and keep wholesome.

The identical quantity of fats, however, will go away us with 98 energy after digestion, whereas carbs differ from 90 to 95, relying on whether or not they’re refined, resembling white bread and pasta, or advanced and wholegrain. A meals’s fibre content material will even play an enormous function. Fibre is a kind of carb, and works to sluggish the discharge of sugar into the bloodstream.

Dr Yeo says: ‘It’s largely protein and fibre that make our our bodies work more durable. The facet impact of consuming these meals is that you just’ll find yourself consuming fewer energy, which is nice if you wish to shed extra pounds. And in case your physique is working more durable to digest one thing, it’s an excellent marker that what you’re consuming is good-quality meals. It’ll be higher for you and comprise extra vitamins.’

What complicates issues additional is that every of us has our personal metabolic fee, which might additionally affect how rapidly or slowly we course of energy. Registered dietitian Clare Thornton-Wooden, spokesperson for the British Dietetic Affiliation, says: ‘The calorie labels on packaging are only a information as a result of what number of energy we use is determined by our physique dimension, age, how a lot muscle mass we now have and our existence. I’d use 500 energy much less in a day once I’m simply sitting at my pc and never transferring round. We should always take this stuff into consideration – in addition to what we’re consuming. It’s completely true that not all energy are equal.’

Dr Yeo explains that the large drawback in trendy life is that we’re ‘consuming an excessive amount of meals wherein our our bodies don’t should work onerous to extract the energy’. He’s speaking about ultra-processed meals, which has gone by means of a mechanical or engineered course of.

Roughly 50 to 60 per cent of all energy we eat within the UK come from such meals. And it could possibly be catastrophic for our well being. These meals – mostly gadgets resembling pizzas, sausages, bacon, reconstituted meat and prepared meals – are larger in salt, sugar and fats to make them style good. And since they’re decrease in fibre and protein, the proof exhibits we eat extra to make up for it.


One research adopted 20 wholesome adults for 2 weeks and allowed them to eat as a lot or as little as they wished. Half got an ultra-processed food regimen, whereas the opposite half got a food regimen of wholefoods. Each diets had roughly the identical variety of energy per portion. However these following the processed food regimen ate round 500 energy a day extra, and gained on common two kilos.

There’s additionally ample proof that extra individuals are overweight in nations the place ultra-processed meals make up a broader proportion of the food regimen. Even choices we assume are ‘more healthy’ fall below the ultra-processed bracket. ‘Vegan burgers and oat milk are marketed as wholesome, however by definition they’re processed to inside an inch of their lives,’ Dr Yeo provides. ‘For those who assume you’ll be getting as many vitamins from them as from actual meals, you’re fooling your self. Usually these merchandise merely have higher PR.’

Most specialists agree that the best way to shed extra pounds is to cut back your calorie consumption. However moderately than chasing restrictive methods which solely work within the quick time period as a result of they’re unattainable to stay to – resembling slicing out carbs or fats, or solely consuming meat – the secret is to eat as many ‘actual’ meals as potential, which is able to naturally be decrease in caloric availability and better in vitamins. Meaning wholegrains, contemporary fruit and greens, legumes, lean meats, fish or proteins resembling nuts and tofu.

‘If we are able to get the Authorities and business to show caloric availability, moderately than calorie content material,’ says Dr Yeo, ‘it means folks could make an knowledgeable alternative – which may make an enormous distinction.’ 

Dr Giles Yeo’s e book Why Energy Don’t Rely: How We Acquired The Science of Weight Loss Improper is printed by Orion, worth £14.99. To order a duplicate for £12.74 till 12 September go to or name 020 3308 9193. Free UK supply on orders over £20. 

Learn extra

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button