This hidden message that annoys scientists – L’Express

“Coca-Cola concerts”. Coca-Cola torchbearers. A Coca-Cola food court, Coca-Cola fountains, “Coca villages”, Coca-Cola advertisements, athletes supported by Coca-Cola, Coca-Cola for athletes and officials… The leading partner of the Olympic Games, far ahead of other sponsors, the American multinational will repaint Paris in its colours this summer, as all the other Olympic cities have done before the French capital. The love affair between Coca-Cola and the Games has been going on since 1928. The company created by pharmacist John Pemberton was looking to make itself known in Europe: it delivered a thousand cases of its soda to athletes and spectators. Since then, Coca-Cola’s support for the most publicised event on the planet has never wavered.

A question of image and visibility: the Olympic Games are an incomparable “business accelerator”, as Claire Revenu, Coca-Cola’s Paris 2024 general manager, recently recalled. The firm also claims to want to “bring the magic of the Games to as many people as possible”, or to take advantage of the Parisian event to “show that a circular economy for packaging is possible”. But the Atlanta group’s interest in sport is not limited to the Olympic Games. It also sponsors an ever-growing list of competitions, in all disciplines: football, rugby, tennis, judo, sailing, tennis, etc. “It’s a constant in Coca’s communication, a sort of subliminal message aimed at emphasizing sport as a way to offset the risks associated with consuming their products containing large quantities of sugar and to fight against the obesity epidemic”, decodes Professor Serge Hercberg, former president of the National Nutrition Health Program.

The goal is clear: to make weight gain an individual responsibility. If you’re fat, it’s because you’re not moving enough. “From multiple works of researchers and internal documents to the firm have demonstrated that this promotion of physical activity represents a strategy deliberate to minimize the role of food in general, and junk food and sodas in particular, in excess weight,” recalls Mélissa Mialon, junior professor at Inserm at the School of Advanced Studies in Public Health in Rennes. A message that is actually quite pernicious because, contrary to popular belief, physical activity in general and sport in particular do not make you lose weight. Or, in any case, not much.

Walking for 30 minutes burns 150 calories

“We conducted a broad review of the scientific literature, which is abundant on this issue: it is now clearly demonstrated that physical activity has an effect on weight, but that this remains limited, of the order of two to three kilos on average, even if there is a strong inter-individual variability”, summarizes Professor Jean-Michel Opperthead of the nutrition department at the Pitié-Salpêtrière hospital (AP-HP) in Paris. First explanation, the volume of activity required to cause a sufficient caloric deficit is very significant. “By walking for thirty minutes, we lose around 150 calories, while an adult of 70 kilos already expends 1500 for their basic metabolism (Editor’s note: the functioning of their body), to which we must add 20 to 30% for daily physical activity. Some 150 calories is therefore very little, and in real life, most of us cannot devote several hours a day to sport”, continues Professor Oppert.

Then, powerful mechanisms of compensation are implemented. After several millennia of scarce food, even famine, the human body has evolved to defend its reserves. “We still don’t understand everything in detail, but we know that by emptying the sugar stored in the muscles, energy stress signals are sent to the brain. These hormones will stimulate the feeling of hunger there,” says Cédric Moro, Inserm research director at the Institute of Metabolic and Cardiovascular Diseases in Toulouse.

Not content with increasing intake, our body could trigger a second adaptation mechanism by reducing its expenditure. For a long time, specialists believed that the more active we were, the more we developed our muscles, and the more energy expenditure increased, including at rest. But the use of cutting-edge technology, doubly labeled water, has recently come to shake up these representations. By having individuals ingest water enriched with two non-radioactive isotopes, then monitoring its elimination through urine, it is possible to determine the quantity of carbon dioxide produced, itself an exact reflection of our energy consumption. Work carried out by an international consortium of researchers suggests that, far from the “additive” model that has long been in use, our body reduces its basic metabolism when it is jostled by significant amounts of physical activity.

To lose weight, a “rebalancing of food” remains the key

These recent results remain highly debated within the scientific community. But they could help explain why the needle on the scale moves little, even when you spend hours sweating in the gym. To lose weight, a “rebalancing of food”, in other words maintaining a balanced diet, without deprivation but without excess, over time, remains the key. This does not mean, of course, that physical activity is useless. “Sport helps you not to gain weight and it also helps you not to gain weight again. This is very important because we know that it is difficult to maintain weight loss over time”, notes Audrey BergouignanCNRS research director at the Hubert Curien Multidisciplinary Institute in Strasbourg. Sport and physical activity in the broad sense are also essential for staying healthy and preventing heart attacks, strokes, diabetes and even cancers.

However, moving does not compensate for the harmful consequences for our body of an excessive sugar intake. Beyond weight gain, sugar has its own effects on health: metabolic syndrome, dyslipidemia, atherosclerosis, which are the breeding ground for cardiovascular diseases and diabetes. “Hundreds of epidemiological studies document this, independently of other variables including physical activity,” emphasizes Serge Hercberg. And this is even more true for sodas. “These liquid calories do not trigger the usual mechanisms of satiety, so we tend to swallow a lot of them, and not eat less for it,” emphasizes Cédric Moro. The only exception is athletes, precisely. “They consume a lot of sugar without experiencing these health problems, but this observation is absolutely not applicable to the levels of physical activity found in the general population,” insists Audrey Bergouignan.

Should we then turn to “light” drinks, where sweeteners replace sugar? Various studies based on the French cohort Nutrinet-Santé have shown an association between the consumption of some of these fake sugars and an increased risk of type 2 diabetes, cardiovascular disease and cancer. The World Health Organization has also classified aspartame as “possibly carcinogenic to humans”. However, nutritionists do not go so far as to call for a ban on sodas. They would just like to limit their consumption – and therefore their promotion. The High Council for Public Health has been recommending for several years now that advertising for products that are too fatty and too sweet be regulated. And in particular, to prevent sponsorship or event sponsorship operations. An opinion that, clearly, does not carry much weight compared to Coca-Cola’s millions of euros.