Tufts University. US / Nutrition and Diabetes. 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 brain’s food cravings.
The first-of-its-kind study
used MRI scans of the brain’s 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.“We don’t 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 brain’s 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 brain’s 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
brain’s 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.”