That vicious cycle of overeating because you are sad and you’re sad because you overeat is actually based on how food affects your brain. Much like drugs, rich foods can have you crashing into depression.

The movie character Fat Bastard, played by Mike Meyers in Austin Powers: The Spy who Shagged Me, popularized the “vicious cycle” expression but it is more than just a line played for laughs. Much like how drugs affect dopamine levels, high-fat foods also affect hormones that are associated with your emotions.

The study was led by Stephanie Fulton, PhD, from the University of Montreal Hospital Research Centre. For the study, researchers fed mice different foods to determine any behavioral changes based on food selection. The brains of the mice were also evaluated for any changes.

Dopamine is released by the brain in both humans and animals and is associated with reward-based behavior. The brain secretes dopamine, which produces good feelings in animals and humans that encourages positive behavior. If a person or animal does well, such as getting an “A” on a test or completing a maze, dopamine is released and the animal or person associates that good feeling with the positive result, encouraging them to act similarly in the future.

Illicit drugs increase dopamine production but that can also lead to the depression, or crash, drug users feel when they are not taking drugs causing them to want to keep using drugs in order to get that good feeling. Food acts in a similar way, according to researchers.

The mice that were fed higher-fat foods displayed more signs of being anxious or being depressed. The higher-fat diet mice tended to avoid open areas and did made less effort to escape from being trapped. Even more importantly, high-fat foods changed certain brain behavior in mice.

CREB, or cAMP response element-binding, is a molecule that plays a role in the formation of spatial learning in the brain as well as acting certain genes in the brain.  The higher-fat diet mice had increased levels of CREB and according to previous research; CREB may play a role in fear response.

Additionally, the stress-related hormone corticosterone was also elevated in higher-fat diet mice. The study helps underscore the impact of our food choices. What we eat may alter our behavior causing us to reach for a donut because we associate that food with feeling good, leading to a downward spiral of unhealthy food choices.

Future studies can determine if higher-fat foods and foods that are high in sugar play a similar role in human behavior. The brain’s reward-system and hormones associated with good feelings may be affected by what we eat and it is important to understand the different mechanisms involved in obesity and diseases related to obesity.

The study was published in the Journal of Visualized Experiments.