A new study from the University of Maryland suggests that a person’s level of exercise can influence the impact of the genetic predisposition to being overweight. Several genetic variants such as the fat mass and obesity associated (FTO) gene have been linked to obesity but it appears that none is wholly responsible for it. It is known that half of all Europeans carry either one or two copies of this gene.

For the study, researchers analyzed DNA samples from 704 healthy Amish adults, average age 43.6, and also conducted a series of physiological tests on the participants, including recording their physical activity over a seven-day period. Evadnie Rampersaud, MSPH, PhD, then of the University of Maryland School of Medicine and now of the University of Miami, and colleagues examined the role of physical activity and of a healthy lifestyle in health efforts to combat obesity.

Participants were divided into two groups: people with high activity levels and people with low activity levels. Among volunteers, 54 percent of men and 63.7 percent of women were overweight, and 10.1 percent of men and 30.5 percent of women were obese. They were fitted with “accelerometers,” measuring their movements over a period of time.

At the end of the study, researchers found that people with certain variations of the FTO gene were more likely to be overweight, but the results of the study also showed that being genetically predisposed to obesity “had no effect on those with above average physical activity scores.” Overall, the gene variants are associated with a greater than 20% risk for obesity, the researchers said.

“Our results strongly suggest that the increased risk of obesity due to genetic susceptibility can be blunted through physical activity,” Dr Soren Snitker, who led the research, said.

“These findings emphasize the important role of physical activity in public health efforts to combat obesity, particularly in genetically susceptible individuals,” the authors of the study concluded in the September 8 issue of the journal Archives of Internal Medicine. This was the second study which suggested that having one or multiple copies of FTO gene variants had no effect on body weight for people who were the most physically active. Therefore, people should have a healthy diet and be physically active in order to prevent diseases.

A report released by the U.S. Centers for Disease and Prevention shows that 25.6% of Americans are obese, which puts them at risk for high blood pressure, diabetes and heart disease. The findings show a constant increase in the obesity rates in the last 15 years. Mississippi, Tennessee and Alabama are the states with the highest rate of obesity.

Another study found that 50 to 60 minutes of exercise a week or at least 55 minutes of exercise are enough for people who have lost weight and are trying to keep the weight off. Approximately 30 minutes a day, five days a week, of brisk walking should burn about 1,000 calories, researchers said.