Overeating due to Lack of Self-Control? Brain Reward Gene Influences Food Choices

Statistics show that 17 percent of youth are affected by obesity in the United States alone--triple the rate from just one generation ago. 

Yet a recent study looks at how a particular gene involved in the brain's reward system helps to contribute to overeating and obesity in adults, not poor self-control.

In fact, similar variants fo this same gene have been linked to childhood obesity, particularly in young gilrs, according to lead study authors Dr. Patricia Silveira and Prof. Michael Meany of McGill University and Dr. Robert Levitan of the University of Toronto.  Researchers believe that the obesity gene can be linked to three factors: genetic predispositions, environmental stress and emotional well-being. 

"In broad terms, we are finding that obesity is a product of genetics, early development and circumstance", Meaney said, via a press release, who is also Associate Director of the Douglas Mental Health University Institute Research Centre.

The researchers' findings are part of the MAVAN (Maternal Adversity Vulnerability & Neurodevelopment) project, headed by Meaney and Hélène Gaudreau, Project Coordinator. Their team studied pregnant women, some of whom suffered from depression or lived in poverty, and followed their children from birth until the age of ten.

The study researchers examined 150 four-year old MAVAN children by giving out a snack test during meal time. The children had to decie between a healthy or non-healthy food choice. Mothers also were asked to complete a questionnaire based on their child's normal food consumption and preferences. 

"We found that a variation in a gene that regulates the activity of dopamine, a major neurotransmitter that regulates the individual's response to tasty food, predicted the amount of 'comfort' foods -- highly palatable foods such as ice cream, candy or calorie-laden snacks -- selected and eaten by the children", said Dr. Silveira, via the release. "This effect was especially important for girls who we found carried the genetic allele that decreases dopamine function."Most importantly, the amount of comfort food eaten during the snack test in the four- year-olds predicted the body weight of the girls at six years of age," Meaney said, via the release, "Our research indicates that genetics and emotional well-being combine to drive consumption of foods that promote obesity. The next step is to identify vulnerable children, as there may be ways for prevention and counseling in early obesity stages".

More information regarding the release can be found in the journal Appetite.