Two recent articles published in the journal Cell raise some interesting questions about genes and body weight. It has been known for some time that certain genes increase risk for obesity, but there is an ongoing debate about how genes result in obesity.
One of the studies used genetic mapping and health information to establish a genetic risk profile for obesity. Another found that mutation to a specific gene associated with appetite control was predictive of body weight. This research points towards the influence of biology on feelings of hunger and satisfaction with meals. Genetics account for some of the variation in metabolism- that is how many calories we burn at rest and how efficiently we extract calories from food- but there are many other variables that tend to have a greater influence on our calorie needs like quantity of muscle mass and physical activity. We can consider appetite in a similar way, influenced by multiple factors both biologic and psychological. I’ve written about appetite before, mostly focusing on how what we eat, when we eat, and how we eat influence our perceptions of fullness and hunger.
Many people with health conditions related to obesity struggle to lose weight, some studies estimate that 1 in about 150 will achieve weight loss putting them into the “normal” BMI range. However, research also shows that 1 in 5-10 people with obesity are able to lose 5% of their body weight and keep it off. This level of weight loss will improve health conditions related to body weight. Genes controlling hunger may help explain this weight loss struggle.
Genes are not destiny, they change our risk for disease. Without a trigger, a genetic predisposition for diseases like obesity or diabetes won’t be active. Triggers include how we eat, move, handle stress, sleep and toxin exposure. Additionally, there is a positive way to look at this relationship between genes and disease; that by leading healthy lives we can prevent disease at the genetic level. Things like exercise and whole foods turn on or off genes which influence disease and health. By creating the right conditions for our genes, we create the right conditions for health.