Cover the grill. A recent study has found that a common chemical produced by grilling foods may play a significant role in causing obesity, type 2 diabetes and insulin resistance.

Doctors have been struggling to find ways to reverse, or at least stem, the tide of obesity. Two-thirds of Americans are overweight or obese, and current methods for weight loss be it diet, exercise, drugs, and surgery have all been disappointing. Obesity, in turn, is also associated with a number of diseases, like type 2 diabetes and heart disease. Researchers have since concluded that the best way to eliminate obesity is to prevent people from being obese altogether. Now a study has found yet another risk factor for obesity: AGEs.

The study was conducted by Weijing Cai and his colleagues at the Mount Sinai School of Medicine. Their findings have been published in the Proceedings of the National Academy of Sciences of the United States of America. In studies performed on mice, sustained exposure to a compound called methylglyoxal (MG) caused the mice to gain a significant amount of weight to their abdomens. The compound also caused early insulin resistance, and type 2 diabetes. MG is a type of advanced glycation endproduct (AGEs), produced when food is cooked using dry heat. AGEs have also been found to reduce the effectiveness of the body's inflammation response.

In the study, one group of mice was fed MG while another group of mice were not. Both were fed diets with the same amount of calories and fat. Over the four generations, the mice that were fed a diet with MG had more body fat and developed early insulin resistance. The control group did not exhibit those characteristics.

The abdominal fat in mice fed MG was converted into fat cells that prevented the metabolism of glucose and impeded fat turnover. This inhibited process, in turn, contributed to the development of insulin resistance and diabetes.

The study authors recommend that people cook foods by stewing, poaching, or steaming meat and vegetables, rather than grilling them.