"There are currently few drugs that actually help you lose weight," explains Paul Fletcher, a co-author of the study. "Developing new drugs is expensive and risky, and our study shows that we can use brain imaging to predict which drugs might work," he adds. The researchers used functional MRI to measure brain activity while a group of obese volunteers looked at images of foods high in calories – like a chocolate cake – and low in calories – like a plate of broccoli. And they found that while the brain reacted more intensely to higher calorie foods in a normal way, under the effects of sibutramine the response to chocolate cake and similar foods was reduced both in the hypothalamus and in the amygdala. In addition, in two weeks of treatment it was found that these patients ate less and lost more weight than their colleagues, treated with a placebo.
"These results remind us that the main cause of obesity in the West is eating too much, and this behavior is regulated through the brain circuits of satiety and reward, " says Fletcher.
