Overeating changes your body clock. Mice fed a high-fat diet will wake up and chow down, scientists have found, which may explain those late-night cravings.
Fatty, salty, sugary foods alter your brain chemistry the same way cocaine does. They trigger the brain's production of dopamine, a feel-good neurotransmitter. A 2010 study in Nature Neuroscience found lab rats fed a poor diet exhibited similar characteristics of animals addicted to heroin and cocaine.
Overeating can make you stressed and depressed. A 2012 study found mice fed a high-fat diet had elevated levels of corticosterone, a stress hormone, and exhibited "pro-depressive effects," the Montreal researchers said.
Overeating for even brief periods can have permanent effects on body composition. In 2010, Swedish researchers found that a four-week binge by a group of normal-weight people resulted in them having gained an average of 3.3 pounds and higher LDL cholesterol levels - even a year later.
Desserts rich in fructose, such as donuts and apple pie, can keep a binge going. A January study in JAMA that compared glucose and fructose found that fructose increased the amount of blood flowing to the brain's hypothalamus, signalling the person was still hungry.