1 of 1Full SizeNEW YORK (Reuters Life!) - It's official. That tub of ice-cream really can control your brain and say "eat me."

A U.S. study by UT Southwestern Medical Center at Dallas has found that fat from certain foods such ice-cream and burgers heads to the brain.

Once there, the fat molecules trigger the brain to send messages to the body's cells, warning them to ignore the appetite-suppressing signals from leptin and insulin, hormones involved in weight regulation -- for up to three days.

"Normally, our body is primed to say when we've had enough, but that doesn't always happen when we're eating something good," said researcher Deborah Clegg in a statement.

"What we've shown in this study is that someone's entire brain chemistry can change in a very short period of time. Our findings suggest that when you eat something high in fat, your brain gets "hit" with the fatty acids, and you become resistant to insulin and leptin.

"Since you're not being told by the brain to stop eating, you overeat."

The researchers also found that one particular type of fat -- palmitic acid which is found in beef, butter, cheese and milk, -- is particularly effective at instigating this mechanism.

The study was performed on rats and mice but the scientists say their results, published in The Journal of Clinical Investigation, reinforced common dietary recommendations to limit saturated fat intake as "it causes you to eat more."

The study was conducted by exposing rats and mice to fat in different ways -- by injecting various types of fat directly into the brain, infusing fat through the carotid artery or feeding the animals through a stomach tube three times a day.

The animals received the same amount of calories and fat and only the type of fat differed. The types included palmitic acid, monounsaturated fatty acid and unsaturated oleic acid which is found in olive and grapeseed oils.

"The action was very specific to palmitic acid, which is very high in foods that are rich in saturated-fat," said Clegg.

(Writing by Belinda Goldsmith, Editing by Miral Fahmy)