In 2007, the FTO (fat, mass, and obesity) gene was discovered which predisposes humans to develop obesity. This obesity gene is found in about 75% of people from Europe, and African Americans but only 44% of Asians.

People with one copy of the FTO gene have an increased risk of obesity of 30%. A person with two copies of the FTO gene have a risk of obesity of 70%. Dr. Ruth Loos recently did an analysis of dozens of studies that included over 200,000 individuals. 

Some of the people who exercised regularly—the equivalent of walking for 30 minutes 5 days a week—turned off their obesity genes. There was an across the board 30% reduction in obesity for those who exercised, no matter how many copies of the FTO gene they had.