Eating junk food increases anxiety.
Many people seek solace in fatty food treats during times of stress but this can actually have an adverse effect.
A team from the University of Colorado Boulder discovered that rats had their gut bacteria disrupted when fed a high-fat diet - altering the brain chemicals that cause anxiousness.
During the study, scientists collected faecal samples from two groups of rats who ate either a standard or fatty diet for nine weeks and found that the rodents on the unhealthy diet had significantly less diverse gut microbiome.
Professor Christopher Lowry, the lead author of the research, said: "Everyone knows that these (high-fat items) are not healthy foods, but we tend to think about them strictly in terms of a little weight gain.
"If you understand that they also impact your brain in a way that can promote anxiety, that makes the stakes even higher."