New York, Sep 2 (IANS): With measures such as behaviour change education it is possible to reverse the addictive power of unhealthy food while also increasing preference for healthy foods, says a new study.

Scientists have suspected that once unhealthy food addiction circuits are established they may be hard or impossible to reverse, subjecting people who have gained weight to a lifetime of unhealthy food cravings and temptation.

But it may be possible to train the brain to prefer healthy low-calorie foods over unhealthy higher-calorie foods, the findings showed.

"We saw here that it is possible to shift preferences from unhealthy food to healthy food without surgery, and that MRI (magnetic resonance imaging) is an important technique for exploring the brain's role in food cues," said first author Thilo Deckersbach, a psychologist at Massachusetts General Hospital in the US.

"We do not start out in life loving French fries and hating, for example, whole wheat pasta," said corresponding author Susan Roberts from Tufts University in the US.

The researchers studied the reward system in thirteen overweight and obese men and women.

Eight of them were participants in a new weight loss programme designed by Tufts University researchers and five were in a control group and were not enrolled in the programme.

Among those who participated in the weight loss programme, the brain scans revealed changes in areas of the brain reward centre associated with learning and addiction.

After six months, this area had increased sensitivity to healthy, lower-calorie foods, indicating an increased reward and enjoyment of healthier food cues.

The authors hypothesised that several features of the weight loss programme were important, including behaviour change education and high-fiber, low-glycemic menu plans.

The study appeared online in the journal Nutrition & Diabetes.