Binge eating in relation to addiction: Evidence from an animal model of sugar addictin

Binge eating is most often thought of as a maladaptive behavior associated with bulimia nervosa. However, this behavior is also noted in patients with obesity, making it of interest to study within the context of the rapidly-spreading obesity epidemic. It has been suggested that some individuals may develop addictive-like behaviors when consuming palatable foods in a binge pattern, which can lead to overeating and subsequent weight gain. This chapter summarizes the findings of several animal models of binge eating, all of which provide unique insights into the behavioral and physiological bases of abnormal eating patterns. Next, the behavioral and neurochemical similarities between binge consumption of a sugar solution and addictive-behaviors, similar to those seen in cases of drug abuse, are reviewed. These behaviors can be categorized as 1) "bingeing," or the intake of unusually large amounts of food in a discrete period of time, 2) opiate-like "withdrawal," as indicated by signs of anxiety and somatic distress, and 3) "craving," which is measured during sugar abstinence. Signs of both locomotor and consummatory "cross-sensitization" between sugar and drugs of abuse have also been found. Underlying these behaviors are alterations in dopamine, opioid and acetylcholine functions in the nucleus accumbens, a brain region that processes reward and motivation. Distinctions are made between bingeing on fats and sugars, which have different effects on behavior and body weight. Drawing on clinical and preclinical findings from other laboratories as well as our own, we present the theory that bingeing on some palatable foods, sugar in particular, can result in addictive-like behavior.