To Snack Or Not To Snack

Genetics may play a role in determining why some people can avoid tempting foods until they're hungry and others can't, says a Tufts Nutrition expert.

Boston [10-21-02] When Tufts nutrition expert Susan Roberts was in kindergarten, she remembers bringing cupcakes into class on her birthday. While her fellow classmates reached for the sweets, Roberts always wondered why her teacher refused. Four decades later, the Tufts scientist knows why: a concept she's termed "low disinhibition," which Roberts says may be the strongest predictor of a person's ability to maintain a healthy body weight.

"In a study of more than 600 women, Tufts researchers found that thinness is part and parcel of low disinhibition," reported The Los Angeles Times. "The lower the women scored on a scale of disinhibition, the lower their body mass index."

Roberts - a nutrition professor at Tufts' Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy-defines disinhibtion as a person's lack of restraint towards food. The more disinhibited a person is, Roberts told the Times, the more likely he or she is to eat food when not hungry.

Someone like Roberts' kindergarten teacher has low level of disinhibition, which is believed to be determined, at least in part, by genetics. The Tufts scientist says these people are not inclined to snack when full-regardless of how tasty the food may look.

But for people with a high level of disinhibition, passing up snacks may be a much harder task.

"Disinhibited eating is very strongly associated with obesity," Roberts -- chief of the Energy Metabolism Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging --told South Africa's News 24. Roberts says being disinhibited can also predict weight gain-which can result in a weight gain of more than 30 pounds over an adult's life.

But genetics aren't the only factor.

"We live in a culture that encourages disinhibition," Roberts told the Times. "We have large portions and menu items called 'Death by Dessert'. The possibilities for opportunistic overeating when you are not hungry are overwhelming."

While "Death by Dessert" may sound appetizing, the consequences of overeating are serious enough to make you lose your appetite. Overweight individuals are more likely to develop health problems such as heart disease, stroke, and diabetes, say health experts.

The National Center for Chronic Disease Prevention and Health Promotion estimates that 61 percent of Americans are overweight. Almost 40 million Americans are obese -- or morbidly overweight.

But according to Roberts, it's possible to reverse the trend. While disinhibition levels appear to be genetically fixed, conscious decisions to alter eating habits can make a difference.

"Being a restrained eater helps offset the effect of disinhibition," Roberts told News 24. "Restrained eaters are those who count calories (and) tend to shop for low-fat foods. So these behaviors seem to help some, but not as much as not overindulging when you don't need to."