Experts have long suspected that increased consumption ultra-processed foods in recent years represents one of the main drivers ofobesity epidemic in the world. Last March, a Canadian study revealed in particular that the people who consume the most of these products made industrial ingredients and additives (soft drinks, sweet or savory snacks, ready-to-eat meals, etc.) have a 32% higher risk of becoming obese compared to those who consume the least. This time, researchers from the National Institute of Diabetes and Digestive and Kidney Diseases have discovered the mechanism that would be involved in this phenomenon.
Their study consisted in comparing the differences of consumptioncalories and weight gain between a diet based on ultra-processed foods and a classic diet. A total of 20 healthy volunteers were recruited into the NIH Metabolic Clinical Research Unit for one month. Participants were to follow only one or the other of these diets for two weeks before redeeming the instructions. They received three meals a day and had access to bottled water and ultra-processed snacks or not throughout the day. They were allowed to eat as much as they wanted and the amounts consumed were measured.
An increase in weight even if the meals are equivalent
For example, a breakfast made from ultra-processed foods included refined cereal, a bagel with cheese, or a pre-made muffin. In the other case, it was simple Greek yogurt, oatmeal flasks, fruit and nuts. The researchers found that even when the two diets were similar in amounts of carbohydrate, fat, sugar, salt and calories consumed, participants ate more and were gaining weight with an ultra-transformed diet. “Although we looked at a small group, the results showed a clear and consistent difference between the two diets,” said Prof. Kevin D. Hall, lead researcher of the study.
It turns out that as part of a diet made from ultra-processed foods, participants consumed 500 more calories per day than on a healthy diet. They also ate faster and gained weight, 0.9 kg on average, which was lost on the unprocessed diet. “We need to determine what specific aspect of ultra-processed foods has affected people’s eating behavior and caused them to to gain weight Adds Prof. Kevin D. Hall. For example, it could be that a slight difference in protein levels between the two diets could potentially explain up to half the difference incalorie intake.
“Over time, additional calories are accumulated, and this excess weight can lead to health problems, ”the researchers point out. Studies have shown a link between high consumption of ultra-processed foods and chronic health problems, such as metabolic syndrome, hypertension or irritable bowel. They say, however, that while their study reinforces the benefits of unprocessed foods, it can be financially difficult to limit consumption of ultra-processed foods. “Telling people to eat better may not be effective for some people without better access healthy food », They conclude.