High-calorie junk food might be as addictive as cocaine or nicotine, according to a new study that found over-consumption of these foods can trigger responses in the brain that mimic addiction. Studying rats in a lab setting, researchers found that high-calorie foods could turn them into compulsive eaters, Reuters reports. They also found lower levels of a dopamine receptor, a brain chemical that allows the feeling of reward, just as has been reported in humans addicted to drugs. For the study, researchers from the Scripps Research Institute in Florida fed the rats fatty food like cheesecake, bacon and sausage, as well as healthy food. One group ate a balanced healthy diet; one got healthy food, and access to high-calorie food for one hour per day; another group got healthy meals and unlimited access to high-calorie foods. The rats in the third group developed a preference for high-calorie food and quickly became obese.