Thin people would have a specific genetic variation, which, even without them paying attention to their diet or their physical activity, allows them not to gain weight.
- 1% of the population could eat all they want without fear of gaining weight
- A specific variation of a gene, the ALK gene, would explain this particularity
The organization is sometimes unfair: some people gain weight very quickly, despite their efforts, while others have a stable weight, almost without doing anything. Researchers at the University of British Columbia, Canada, wanted to find out why. In the review Cell, they publish the results of their study: according to them, a genetic variation is linked to thinness. People with it would gain little or no weight.
A variation of the ALK gene
These individuals represent “about 1% of the population”, according to study author Josef Penninger. “They can eat whatever they want and stay metabolically healthy. They eat a lot, don’t exercise all the time, but don’t gain weight.” The researcher and his team used a database including more than 47,000 people aged 20 to 44. They analyzed DNA and clinical data: this allowed them to discover that thin people have a specific genetic variation of the ALK gene.
A potential treatment for obesity?
In a second part of the study, carried out with flies and mice, the scientists found that animals lacking the genetic variation remained thin while consuming very rich food. With the same diet and the same level of physical activity, mice and flies with the genetic variation had less body fat, compared to the others. The researchers suspect this genetic variation to allow thin people to have better energy expenditure. They would like to use this discovery to develop a treatment for obesity. “ALK inhibitors are already used in cancer treatments, explains Professor Penninger, this is a possible target!”
Obesity is also linked to genes
This is one of the rare studies to focus on the genetic specificities of thinness. “Everyone is studying obesity and its genetics,” says Josef Penninger. Among these works are those of the Norwegian University of Science and Technology. Researchers have proven that genes play an important role in the risk of suffering from obesity. 70% of weight gain is linked to genetics according to another research. In total, more than 200 genes are associated with it.
Below, the program Questions aux Experts on “Obesity, fighting received ideas”: