Examining the addictive-like properties of binge eating using an animal model of sugar dependence

The increase in the incidence of obesity and eating disorders has encouraged research efforts aimed at understanding the etiology of abnormal eating behaviors. Clinical reports have led to the suggestion that some individuals may develop addictive-like behaviors when consuming palatable foods. Binge eating is a behavioral component of bulimia and obesity and has also become increasingly common in nonclinical populations in our society. This review summarizes the behavioral and neurochemical similarities between binge eating of palatable foods and the administration of drugs of abuse. An animal model of bingeing on sugar is used to illustrate behaviors found with some drugs of abuse, such as opiate-like withdrawal signs, enhanced intake following abstinence, and cross-sensitization. Related neurochemical changes commonly observed with drugs of abuse, including changes in dopamine and acetylcholine release in the nucleus accumbens, can also be found with bingeing on sugar. These neurochemical alterations are exacerbated when animals binge on sugar while at a low body weight or when the food they ingest is purged. Drawing on other animal models and the clinical literature, parallels between drug abuse and binge-eating behavior are discussed.