Abundant food choices may overwhelm brain, reinforce overeating, UF researchers say

Authorities in the field of food addiction at the University of Florida say new research indicates that overeating and obesity problems might be effectively tackled if people would limit their food choices.

Editorializing in the August edition of the American Journal of Clinical Nutrition, Nicole M. Avena, Ph.D., a research assistant professor, and Mark S. Gold, M.D., chairman of the UF College of Medicine’s department of psychiatry, suggest modern living presents many delicious possibilities for people at mealtime — too many for people who respond to food as if it were an addictive drug.

Their comments are in response to new research by scientists at the State University of New York at Buffalo that shows even obese people lose interest in and eat less of foods that they are repeatedly exposed to — a behavior known as habituation.

“Clearly, school-lunch planners and public health officials should note that diversity in the menu is not necessarily a virtue, and in fact may be associated with promoting excess food intake and increased body mass index,” Avena and Gold wrote.

Before the SUNY at Buffalo study, rigorous research did not clearly indicate whether healthy-weight and overweight individuals responded in the same way to a limited diet. The thought was menu monotony did not constrain people who continually eat far more than their normal energy requirements.

In addition, little is known about the food exposure patterns needed to cause people to lose interest in their food, thereby reducing the likelihood of overeating and subsequent obesity.

The research study, led by Leonard H. Epstein, Ph.D., of SUNY at Buffalo, analyzed the food consumption of obese and non-obese women that either received a macaroni-and-cheese meal every day, or once a week for five weeks.

The women in the group that received macaroni-and-cheese daily for five days reduced their food intake, whether the women were obese or not. Women in the group with a larger variety of choices did not lower their food consumption.

Additional studies are needed to see whether men given fewer food choices would also lower their food intake.

“Variety in palatable food choices appears to be important in determining whether or not habituation or perhaps tolerance to food can develop,” Avena and Gold wrote. “But in our modern-day food environment, monotony and similarity in meals are rare.”

Concepts of food addiction, pioneered for more than three decades by UF, Princeton University and Yale University researchers, suggest that highly palatable foods trigger the same sort of gene expression and release of chemicals in the human brain associated with highly addictive drugs. Even rodents that have excessive amounts of sugar in their diets exhibit signs of drug withdrawal when they return to a normal diet.

“Not every obese person is addicted to food,” Avena said. “But the data are really saying that highly palatable food, rich in fats and sugars, might be difficult to stop taking for the same reasons that it’s difficult to stop taking drugs of abuse. It means we might be able to take lessons from drug-abuse literature when considering ways to reduce consumption of highly palatable foods.”

Further research is needed to learn more about the underlying causes of overeating, the scientists say.

“It is becoming clear that new pharmacologic therapies for overeating may end up being established drug addiction treatments,” the authors wrote.