A new study suggests that it is possible to change the cycle of craving unhealthy foods by retraining the brain to stop activating its reward centers on exposure to a steady stream of high-calorie foods and visual triggers. The U.S. Department of Agriculture (USDA)-funded study addresses concerns among weight-loss experts that when people get used to eating instant-gratification foods, such habits may be nearly impossible to stop or reverse.
The study was conducted by senior coauthor Susan B. Roberts—an expert in developing programs for weight management—and co-investigators. Roberts is with the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Massachusetts. The center is funded by the Agricultural Research Service (ARS), which is USDA’s chief intramural scientific research agency. Roberts is also professor of both nutrition and psychiatry at Tufts University.
The study volunteers were 13 overweight or obese men and women assigned to one of two study groups. One group was placed on an at-home weight-loss intervention of lower calorie foods for 6 months. The other was a no-intervention control group eating normally at home.
To satisfy brain areas linked with cravings—the intervention group’s diet provided about 50 percent of daily calories from “slow-digesting” carbohydrates and high-fiber foods. High-protein foods and healthy fats each provided 25 percent of daily calories. The group received 1 hour of positive reinforcement support sessions most weeks and meal plans that centered on hunger reduction, portion-control, and high satisfaction. They were told to evenly space meals and snacks and to freely use foods from a list of those that could be eaten any time. These tips were designed to keep blood sugar levels even (versus spiking) and to control hunger.
The intervention group achieved significant weight loss—about 14 pounds each.