A healthy body weight is in your genes!

Earlier this month I was at the annual meeting for the Southeast chapter of the American College of Sports Medicine. The keynote address was by a genetic researcher, Dr. Molly Bray, who spoke about the role of genes in health behaviors. While heredity has been linked to body composition (muscularity, body fatness) for some time, the idea that genes can influence health behaviors such as eating and physical activity habits is somewhat new.

I thought this was interesting and a good way to explain individual differences and family similarities in diet, exercise, and obesity so it is the topic of my Health & Fitness column in the Aiken Standard this week. Many people, including many of my colleagues, are uncomfortable with the idea that genetics plays a role in health behaviors. This idea calls into question our traditional belief that people who obese, unfit, or eat poorly simply lack the motivation or willpower that people who maintain a healthy body weight and who eat a healthy diet have. It seems that genes explain at least a portion of these differences.

Does this mean that we are not responsible for our health?  Absolutely not! While genes may influence our appetite, food preferences, physical activity level, and responses to diets and exercise, ultimately we are in control of what we eat and how active we are. But knowing the role of genes in health can help us understand why some people struggle more than others to adopt healthy behaviors. It also helps explain why some people fare better than others in our obesogenic environment.

In my column I mentioned the Heritage Family Study which examined the genetic factors associated with body fatness, fitness, and other health factors. You can learn more about this important study here. I also cited a recent study that reported the discovery of two genes that regulate appetite. You can read a low-science article about that study here or read the hi-sci paper in the American Journal of Clinical Nutrition here.