Scientists are using imaging tests to show for the first time that fructose can trigger brain changes that may lead to overeating.

Associated Press chief medical writer Marilynn Marchione said a new study finds that after drinking a fructose beverage, the brain doesn’t register the feeling of being full as it does when simple glucose is consumed.

What they found was that MRI scans show that brain activity was very different after people drank fructose beverages rather than glucose. Fructose did not activate the areas of the brain that say ‘I’m satisfied, I’m full, I’ve had enough.’,” Marchione explained.

It’s a small study and does not prove that fructose can cause obesity, but experts said it adds evidence they it play a role.