Eating fatty foods helps you remember what you were doing when you had the food, researchers from the University of California, Irvine said.

They said in a news release their work could give insights into appetite control that could fight obesity.

Previous work showed that oleic acids from fat turn into something called oleoylethanolamide -- OEA -- in the intestines. OEA helps tell the brain when you are done eating.

Daniele Piomelli and James McGaugh now say that OEA also helps turn short-term memories into long-term ones.

Giving OEA to rodents improved memory retention in two different tests, they said. When cell receptors activated by OEA were blocked, memory retention effects decreased.

"OEA is part of the molecular glue that makes memories stick," Piomelli said. "By helping mammals remember where and when they have eaten a fatty meal, OEA's memory-enhancing activity seems to have been an important evolutionary tool for early humans and other mammals."

Dietary fats help with the absorption of vitamins and protect vital organs. But early people probably did not get to eat fatty foods very often.

"Remembering the location and context of a fatty meal was probably an important survival mechanism for early humans," Piomelli said. "It makes sense that mammals have this capability."

But with today's diet, the process could be part of what makes people crave fatty foods they don't technically need.

The study's results appeared this week in the early online edition of the Proceedings of the National Academy of Sciences, but the news release did not provide details on how much memory was improved or how high a dose was given to the animals.