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Junk food isn't just making your jeans tight. It could be contributing to your ballooning stress and anxiety.

Researchers at the University of Montreal used mice to test the effects of high-fat foods on the brain. The researchers found the mice who ate junk food had "different chemical activity in their brains and exhibited more signs of withdrawal if they stopped eating it," reports the Huffington Post.

Researchers say those same chemicals produced by the unhealthy food are the very same brain chemicals tied to depression. When researchers changed the test subjects diets, the mice were even more withdrawn and stressed out, "launching a vicious cycle of poor eating."

The findings challenge previous scientific thought about the link between food and your mood, in part because junk food is changing the brain before obesity happens.

You can read more about how unhealthy food is messing with your head here.

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