Along with exercise, it's one of the keys to weight loss: cutting calories out of your diet. But depending on what you eat, a new study says that may be easier said than done.

According to the Scripps Research Center in Florida, high-calorie junk food can be as addictive as Nicotine or Cocaine.

For the study, researchers fed three groups of rats different diets. One group got healthy food, another got only junk food and the third got healthy food most of the day and junk food for just an hour.

Researchers found it was okay to enjoy occasional snacks, but over-indulging created addictive responses in the brain.

The results seemed to show that addiction treatments might help some people who are fighting obesity.