Hundreds of genetic regions influence body weight. In most cases, the function of these genes remains unknown.
A new study from Université Laval and the Quebec Heart and Lung Institute Research Centre reports that about 60 genes encode proteins that could influence body weight via their expression in the brain.
The study’s research team concentrated on a brain region that may affect cognitive functions like memory and decision-making, as well as food reward sensitivity, which refers to how enjoyable consuming fatty or sugary food might be. The dorsolateral prefrontal cortex, a part of the brain, is also hypothesized to play a role in hunger and satiety.
The team’s findings are consistent with the idea that the brain is a key component of controlling body weight. This finding might help to explain why people’s BMIs differ so widely.
Lead author Benoît Arsenault, professor at the Université Laval Faculty of Medicine and researcher at the Quebec Heart and Lung Institute, points out that several myths remain in the public domain regarding the impact of genetic factors on body weight.
He said, “I often hear that genes cannot explain why the average weight of the population has increased over the past 40 years when our genes have not changed.”
“The evolving food environment may have influenced food behaviors and energy storage capacity over the last few decades. Individuals with a genetic predisposition to high body weight have a higher weight than before. In contrast, individuals who do not have this predisposition were thin before and are still thin today.”
“The biological role of these proteins in various parts of the brain and their contribution to energy homeostasis, i.e., the balance between food intake and energy expenditure, needs to be studied in more detail.”
“Overall, the results of our study support the existence of a potential interaction between the brain proteome and the evolving food environment. This relationship could influence eating behaviors and energy storage.”
“People living in larger bodies are often victims of prejudice and may experience discrimination, intimidation, or stigmatization. These phenomena associated with fatphobia could affect physical and psychological health.”
“Several studies have shown that factors beyond our control, such as genetics, account for an important proportion of body weight variation across the population.”
“Weight is not a choice. Neither is it a lifestyle habit. We don’t have elevated body weight because we are lazy or lack willpower. Unconscious neuronal mechanisms are at play. The brain is the one in charge. I hope that the results of this study can partly explain why body weight varies so much from one person to another.”
- Eloi Gagnon, Arnaud Girard et al. Genetic control of body weight by the human brain proteome. iScience. DOI: 10.1016/j.isci.2023.106376