Energy balance occurs when there is harmony between energy intake and energy expenditure. Certain genetic variations increase the risk of obesity, but a recent research by scientists from The University of Carolina has found that physical activity could modify the effect of these genes. Energy imbalance occurs when people tend to eat more than they ''lose'' energy and leading physically inactive or sedentary lifestyles. This has led to a global epidemic, where there are more number of people who are obese. Dr. Mariaelisa Graff and colleagues from The University of North Carolina studied the effect on physical activity on the genetic variations that are associated with weight gain.