Researchers find blame game doesn't help obese patients

Kevin Niswender, M.D., Ph.D., assistant professor of Medicine and Molecular Physiology & Biophysics, is three years into a line of basic research that indicates the challenges overweight and obese persons face are really similar to those faced by people with drug addictions.

“People with substance abuse problems have changes in certain parts of the brain and this causes them to continue to use substances and to increase their substance use in order to feel normal, or to have that sense of pleasure that people would get otherwise from healthier activities,” he said.

“Our idea is that people who have similar behaviors with regard to eating may be more predisposed to the development of obesity because they don't experience that sense of reward or pleasure that an individual should feel from eating a more balanced meal.”

Niswender is teaming with Malcolm Avison, Ph.D., professor of Radiology and Radiological Sciences, and translational nutrition scientist Heidi Silver, Ph.D., R.D., on a study designed to investigate the effects of insulin, which is used for treatment of diabetes mellitus, on energy balance, body composition, brain function and other risk factors for cardiometabolic disease.

The study compares how a weight loss diet, with or without a newer type of insulin, affects areas of the brain's dopamine system that are involved in food intake and the sense of pleasure people get from eating.

“This line of basic science research is really opening up a new way of thinking about the problems of obesity and overeating,” Niswender said. “We think now that when one overeats, insulin has a different function. Insulin acts on those areas of the brain where dopamine normally functions to decrease the reward aspect of food intake, thereby helping to limit food intake.

“It is likely that this novel function of insulin is compromised in obese people.”

Study participants need to be between the ages of 31 and 60, overweight (BMI of 30-50), have type 2 diabetes and taking only oral anti-diabetic medication for their diabetes.

The study lasts 26 weeks and includes testing at the Vanderbilt Clinical Research Center and Imaging Institute.

Interested individuals can email m.a.richardson@vanderbilt.edu or fill out the eligibility survey online at redcap.vanderbilt.… ys/?s=tn7m4I

“We do not see overeating and obesity as a simple willpower problem. This is something most overweight people would do anything and everything in their power to change if they could,” Niswender said.

“The science is telling us that there is a very strong biology behind this — there is a very strong mechanism causing people to over-consume the amounts and types of foods and beverages that lead to obesity.”

Provided by Vanderbilt Medical Center