December 16/Eugene, Ore./Oregon Research Institute -- A new study has found that what really draws people to sweet treats like milk and chocolate shakes is not the fat that they contain but actually the sugar.

Scientists tracked the brain activity of more than 100 participants (mainly students) when they consumed chocolate flavored milkshakes. These milkshakes were carrying same amount of calories in them but differed in the amount of fat and sugar.

They found that both the kinds of shakes activated the pleasure centers in the brain but those with more sugar concentration did it more effectively compared to containing fats. It also triggered a food-reward network that plays an important role in compulsive eating.

Surprisingly, they found that sugar was extremely powerful stimulus, and it completely overshadowed fat even when the two were combined in large amounts.

“We do a lot of work on the prevention of obesity, and what is really clear, not only from this study but from the broader literature over all, is that the more sugar you eat, the more you want to consume it,” said Eric Stice, lead author of the study. “As far as the ability to engage brain reward regions and drive compulsive intake, sugar seems to be doing a much better job than fat.”

The study has opened up a new prospect of thinking explanations of reasons that are behind overeating. The developments of the study are published in the journal of Clinical Nutrition.