Content note: discussion of eating disorders

As of April 2022, government policy requires any business serving food with more than 250 employees to place calorie information on their menus. This is part of the government’s new strategy to tackle the country’s obesity problem, including restrictions on certain types of food advertising. This decision has been praised by many, including Diabetes UK, who have demonstrated consistent support for the implementation of more extensive food labelling. After all, obesity is a growing health concern, with its global incidence nearly tripling over a four-decade period; the government estimates the cost of obesity to wider society at £27 billion per year. Obesity can inherently pose risks to health by being associated with co-morbidities such as hypertension and Type II diabetes.

However, it is impossible to overlook the fact that we live in an excessively food-focused society, where stories of dramatic and often unhealthy weight loss frequently flood the internet: think Kim Kardashian’s recent 16-pound weight loss in just three weeks. Is an increased emphasis on caloric intake best for society in the long run? And most importantly, whilst caloric awareness and tracking can be an extremely effective weight-loss method, how accurate are calories when it comes to how our body processes food?

“Many are fearful that the normalisation of checking calorie counts will be damaging”

It is undeniable that calorie counting can be an effective weight-loss strategy. Just going on your phone and browsing the latest available ‘Health and Fitness’ apps shows that tracking calories is a big industry. In theory, it represents a perfect solution: eat less than you use up, and of course, you will lose weight. However, human behaviour is rarely that simple: a 2020 study showed no significant difference in body composition between volunteers using a calorie counting app for eight weeks and a control group. This result may be due to individuals inaccurately tracking what they ate in a day, or a set calorie goal that wasn’t sufficient for weight loss, or something else entirely.

All calories are equal, but some are more equal than others

This somewhat liberal adaptation of a quote from George Orwell’s Animal Farm is perhaps best explained in the words of Dr Giles Yeo, a geneticist from the University of Cambridge, investigating how our genes influence the brain’s control of food intake. Yeo’s recent book Why Calories Don’t Count breaks down aspects of physiology and biochemistry to show that whilst all calories are equivalent from a thermodynamic point of view, calories from different types of food groups are not necessarily used by our bodies in the same way. After all, the term ‘calorie’ was coined to define the energy needed to raise the temperature of 1 gram of water through 1°C.

“Calories from different types of food groups are not necessarily used by our bodies in the same way”

How our bodies use the energy from food is more complex than heating water. Different food groups have different requirements for their processing and hence differ in terms of their ‘caloric availability’. Yeo points out that for every 100 calories of protein consumed, only around 70 calories are estimated to be absorbed, compared to the approximately 97 calories absorbed in the case of fat, arguing that “the system of caloric availability brings all diet plans under one umbrella”.

This idea probably extends beyond macronutrients and onto micronutrients too – weight-loss diets that are entirely focused on calories may well lead to individuals failing to meet their daily requirements for various vitamins and minerals. For example, a randomised control trial found that perhaps unsurprisingly, obese individuals undergoing a recommended low-calorie diet for weight loss experienced micronutrient deficiencies. Whilst for many this was already the case before the dietary intervention, reflecting prior eating habits, this does show that fixation on calories as a weight loss strategy can lead to further deficiencies with potential long term consequences for health.

Calorie counting or calorie awareness?

Maybe, then, the advocation of calorie labelling will have benefits stemming from increased awareness of the energy content in food. You may walk into Five Guys and be surprised to find that your favourite milkshake has over 1000 kcals; you may be put off from ordering it. You now have free and easy access to information that can allow you to make an informed choice regarding what you put into your body. Yeo, too, fully acknowledges that “calorie counts are useful at the point of purchase.” The risk does remain, though, that having constant and unfiltered access to this information could easily lead to a mindset of counting calories without thinking about the nutritional quality of said calories.

Food fixations can be damaging

The new government policy has been openly criticised by many, and not just because it may not be as effective as expected in tackling the country’s increasing prevalence of obesity. Beat, the UK’s primary charity dedicated to helping individuals with eating disorders, has previously criticised policies relating to calorie labelling. Many are fearful that the normalisation of checking calorie counts will be damaging for individuals with a history of disordered eating, as recently shared by Hannah Gillott in Varsity.

Mandatory calorie labelling will provide us with more information that can change how we make choices about our food. However, whether or not calorie labelling is the most efficient way to do this is up for debate. Taking steps to improve public health is of critical importance – it’s just important to make sure that those steps are the right ones.