A small pilot study at Tufts Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) raises the intriguing possibility that following a new behavioral weight-loss program for six months can in turn reprogram your brains food cravings. The first-of-its-kind study used MRI scans of the brains addiction center to see changes in the response to healthy and unhealthy food. The scans showed that it is possible to train the brain to reverse cravings and temptation for unhealthy food, replacing former cravings with temptation for healthy food.
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We dont start out in life loving French fries and hating, for example, whole-wheat pasta, says lead researcher Susan B. Roberts, PhD, Tufts professor of nutrition and founder of the online iDiet weight loss program <www.myidiet.com>. This conditioning happens over time in response to eating-repeatedly-what is out there in the toxic food environment.
Scientists have suspected that this unhealthy conditioning might be difficult or impossible to reverse. So Roberts and colleagues sought to find out whether the brain can be re-trained to support healthier food choices.
REPROGRAMMING: In the study, published in Nutrition & Diabetes, Roberts and colleagues tested the brains reward system in 13 overweight and obese men and women. Eight were participants in the iDiet program, which emphasizes behavior change education and high-fiber, low-glycemic menu plans. Five, not enrolled in the program, served as a control group.
Both groups underwent MRI brain scans at the beginning and end of a six-month period. Among those who participated in the weight-loss program, the brain scans revealed changes in areas of the brains reward center associated with learning and addiction. After six months, this area showed increased sensitivity to images of healthy, lower-calorie foods, indicating an increased reward and enjoyment of healthier food cues. The area also showed decreased sensitivity to images of unhealthy higher-calorie foods.
The weight-loss program is specifically designed to change how people react to different foods, says co-author Sai Krupa Das, PhD, a scientist in Tufts HNRCA Energy Metabolism Laboratory. 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. To the best of our knowledge this is the first demonstration of this important switch.
ENJOYING FOOD: Other studies have shown that surgical procedures like gastric bypass surgery can decrease how much people enjoy food generally.
But this is not very satisfactory because it takes away food enjoyment generally rather than making healthier foods more appealing, notes Thilo Deckersbach, PhD, a psychologist at Massachusetts General Hospital who was first author and co-corresponding author of the study. We show here that it is possible to shift preferences from unhealthy food to healthy food without surgery, and that MRI is an important technique for exploring the brains role in food cues.
Roberts adds, There is much more research to be done here, involving many more participants, long-term follow-up and investigating more areas of the brain. But we are very encouraged that the weight loss program appears to change what foods are tempting to people.