If diets that involve calorie limitations work well initially, it is very common for our weight to start to rise again as soon as we eat normally again. Particularly because this return to the ordinary causes at the heart of our microbiota the multiplication of bacteria called lactobacilli.
These produce metabolites which have the particularity of storing lipids. This also generates at the same time an overall increase in the body’s fat mass, which ultimately ends up being greater than it was before the restrictive diet.
However, a group of scientists from the Institute of Nutrition and Health of the Shanghai Academy of Sciences, whose conclusions were published in the journal Nature Metabolism, in December 2022, proves, through protocols carried out on mice , that an increase in the protein content of their post-diet food intake helps to combat these undesirable phenomena.
Why is this discovery important?
Because it demonstrates, with the action of lactobacilli, one of the levers which explain the weight rebound after a diet, a gain which we would have naturally tended to attribute to menus which became too rich and energetic again or to a lack of physical activity.
The illustration of the negative impact of these microorganisms therefore opens up and offers exciting perspectives for research.
A study carried out on mice
After subjecting them to a restrictive diet for three days, the authors of this study subjected the rodents to three types of dietary regimens, the first high-protein, the second standard protein and the third low-protein. Then, to corroborate these observations, they treated some mice with penicillin, an antibiotic that eliminates lactobacilli, and noted that this drug had the same beneficial effects as the high-protein diet.
What the nutritionist thinks
For Dr Jean-Michel Lecerf, nutritionist and specialist in endocrinology and metabolic diseases, other studies have shown things that are quite similar. “We thus realized that people who were unable to lose weight had an unbalanced microbiota and that making it more “favorable” could allow them to lose weight. What is original, however, in this work is highlighting proteins, because they oppose the fat absorption mechanism, more precisely lactobacilli which increase their metabolism tenfold” he explains.
“Focusing on these proteins could therefore help overcome resistance to weight loss. However, we must take into account the fact thatMice do not have the same microbiota, not the same metabolism and not the same eating habits as us. So, we must not go too quickly and say that everything goes through proteins, firstly because this model cannot necessarily be extrapolated to humans, then because their effect is interesting, but not enough.
But consuming more protein is usefulespecially when we know that 80 to 85% of people regain the weight they lost within 4 to 6 years.
Our expert: Dr Jean-Michel Lecerf, nutritionist, specialist in endocrinology and metabolic diseases, and head of the nutrition & physical activity department at the Institut Pasteur de Lille (IPL)
