The hunt for the fat gene – the one gene responsible for the propensity to gain extra weight – is on and, so far, the findings show that no such gene exists. There are, however, dozens of genes that have been shown to increase ones susceptibility to gaining weight. (1)
While many such genes exist, does it mean you are destined to gain unhealthy amounts of weight if you carry them? Why would the body naturally select genes that make us store fat?
The most famous of these is a very common gene called the FTO (fat mass and obesity-associated) gene which affects how the brain regulates appetite. There is no doubt in our modern culture the FTO gene is linked to carrying more weight. People who have one copy of this gene have an increased risk of gaining 2.6 pounds compared to someone without this gene. If you carry two copies of this gene you will weigh on average 6.6 pounds more than someone without the gene. (1)
But It Might Not Be A Gene Thing!
Studies also show that carriers of this gene will struggle to control their appetite a little more than those without the gene, but show no difference when trying to lose weight with diet or exercise. (1)
In addition, it is known that humans have been carrying this gene long before human concerns with obesity. Hunter gatherers were not fat, yet many had this common gene. Being wired to have a good appetite and store some insulating and hormone-making fat was a good thing and likely a requirement for survival at one point in time.
In conclusion, these weight gaining genes did not all of a sudden appear in the last few decades. We have been carrying them for thousands of generations and the vast majority of these early humans had normal body weights.
Given our new fascination with our genes, we still know little about how to accurately interpret this powerful information. Even as more research is conducted on the FTO and other weight-gaining genes, we need to focus on our diet, stress levels, environment and exercise rather than our genes to reverse this unhealthy trend towards weight gain.