Summary
Excess fat mass and obesity are caused by more energy entering the body than energy exiting the body. Human junk food is exceptionally fattening for rats, and our evolutionary history plays a role in our preference for certain food properties. The release of dopamine in the brain reinforces motivation and behavior, similar to addiction. People exhibit addiction-like behaviors towards modern foods that have extreme reward factors. It can be difficult to control impulses and make healthy choices, especially when tired or stressed. Cooking for oneself and controlling the food environment are important for making healthier choices.