A food or eating addiction is any behavioral addiction that is primarily characterized by the compulsive consumption of palatable (e.g., high fat and high sugar) food items which markedly activate the reward system in humans and other animals despite adverse consequences. Psychological dependence has also been observed with the occurrence of withdrawal symptoms when consumption of these foods stops by replacement with foods low in sugar and fat. Because this addictive behavior is not biological, one cannot develop a trait that codes for an eating disorder, so professionals address this by providing behavior therapy and by asking a series of questions called the YFAS (Yale Food Addiction Scale) questionnaire, a diagnostic criteria of substance dependence. Sugary and high-fat food have both been shown to increase the expression of ΔFosB, an addiction biomarker, in the D1-type medium spiny neurons of the nucleus accumbens; however, there is very little research on the synaptic plasticity from compulsive food consumption, a phenomenon which is known to be caused by ΔFosB overexpression. Description "Food addiction" refers to compulsive overeaters who engage in frequent episodes of uncontrollable eating (binge eating). The term binge eating means eating an unhealthy amount of food while feeling that one's sense of control has been lost. At first, the food addiction comes in the form of cravings, so a person is naturally caught unaware when suddenly they find that they cannot cope without the craving. The person's behavior then begins to shift when the need for more food is not met, in that when the urge is met, binge eating disorder, obesity and bulimia nervosa can result as a consequence. To show this, a study done by Sara Parylak and her peers in the physiology and behavior journal reveals that animal models given free access to food became more emotionally withdrawn after the food was taken away from them due to the anxiogenic-like stimuli (substance) pestering them for more food. This kind of behavior shows that food addiction is not only a self control problem, but that it goes deeper than that, it is the body controlling a person to the point where the individual has no say on what goes into their bodies despite all the consequences that can come from overeating. People who engage in binge eating may feel frenzied, and consume a large number of calories before stopping. Food binges may be followed by feelings of guilt and