Fat Rats Have Addiction-Like Responses to Food

Rats given unlimited access to high-fat foods exhibited addiction-like responses in their brains that could underlie compulsive eating and obesity, researchers say.

A new animal study from the National Institute on Drug Abuse (NIDA) found that the brain mechanisms involved in compulsive eating are often the same as those involved in drug addiction. Both involve dysfunction in the brain’s reward system, researchers said, specifically the brain’s type 2 dopamine receptors (D2DR).

The study found that as the rats became obese, the levels of D2DR in the brain decreased, much as they do in humans addicted to cocaine or heroin. Researchers noted that the mere availability of high-fat food could help trigger overeating.

The study was published online in the journal Nature Neuroscience and will appear in the May 2010 issue.