Body Mass Index (BMI) variations in the population might be caused due to genetic variables to the extent of 50-75%. Researchers from Universite Laval and the Quebec Heart and Lung Institute Research Center, Canada, have discovered 60 distinct proteins produced in the brain might play an important role in regulating body weight after examining the genomes of more than 800,000 people of European origin.
The researchers studied the link between genetic regions associated with body weight and the proteins expressed in the brain. Eloi Gagnon, a doctoral student in clinical and biomedical sciences at the Universite Laval Faculty of Medicine and first author of the study said, “Previous study showed that hundreds of genetic regions influence body weight. In most cases, the function of these genes remains unknown. Our study reports that about 60 of these genes encode proteins that could influence body weight via their expression in the brain.”
The research team focussed on the brain’s region which could influence food reward sensitivity, such as the pleasure felt when eating fatty or sugary food, as well as cognitive processes including decision-making and memory for the study. This brain region, the dorsolateral prefrontal cortex, is also thought to be implicated in appetite and satiety.
The researchers’ results support the hypothesis that the brain plays a critical role in body weight regulation. This discovery could explain why BMI varies significantly from one person to another.
The research’s lead author and professor at the Universite Laval Faculty of Medicine and researcher at the Quebec Heart and Lung Institute, Benoit Arsenault, pointed 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.”
Genetics and Food Environment
According to the researchers, the evolving food environment may have influenced food behaviours and energy storage capacity over the last few decades. Professor Benoit Arsenault added, “Individuals with a genetic predisposition to an elevated body weight have a higher weight than before, whereas individuals who do not have this predisposition were thin before and are still thin today.”
The researchers believe that 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,” said Professor Arsenault.
He stressed that the people living in larger bodies are often victims of prejudice and may experience discrimination, intimidation, or stigmatization. These phenomena associated with fatphobia could have repercussions on physical and psychological health. The researcher also notes that 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,” concluded Benoit Arsenault.
[with inputs from ANI]