In a small, preliminary study, researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University and at Massachusetts General Hospital found it may be possible to train the brain to prefer healthy foods over calorie-laden, additive-rich fare.

"We don't start out in life loving french fries and hating, for example, whole wheat pasta," says senior and co-corresponding author Susan B. Roberts, Ph.D. "This conditioning happens over time in response to eating -- repeatedly -- what is out there in the toxic food environment."

Knowing that those who are overweight can suffer a lifetime haunted by cravings, Roberts and her team of researchers worked with 13 overweight and obese men and women to examine their reward systems.

Eight of the participants were enrolled in a weight loss program developed by researchers at Tufts called the iDiet and the remaining five served as the control group and were not given the intervention until six months later.

According to co-author Sai Krupa Das, Ph.D., a scientist in the Energy Metabolism Laboratory at the USDA HNRCA and an assistant professor at the Friedman School, the iDiet is designed to change how the brain reacts to different foods.

Among its offerings are high-fiber, low-glycemic menus and behavior change education by means of interactive online tools that tell followers what to keep in their homes and how to order healthy foods at restaurants. The diet intends to reduce hunger and those who follow it are allowed a variety of foods and to eat three full meals and snacks per day.

To test the diet, the test and control groups underwent magnetic resonance imaging (MRI) brain scans at the start and end of the six-month study.

After six months, scans from the test group revealed increased sensitivity to healthy, low-calorie foods in the brain's reward center associated with addiction and learning, indicating an actual increase of enjoyment of the very idea of healthy foods.

In contrast, the scans revealed decreased interest in junk food.

"The weight loss program is specifically designed to change how people react to different foods, and our study shows those who participated in it had an increased desire for healthier foods along with a decreased preference for unhealthy foods, the combined effects of which are probably critical for sustainable weight control," says Dr. Krupa Das.

"To the best of our knowledge, this is the first demonstration of this important switch."

Roberts admits that there is much more research to be done, surely involving a larger sample size, but she and her team are pleased with the promise their diet shows.

The study was published in the journal Nutrition & Diabetes.