Binge eating in rats with limited access to vegetable shortening.

In this protocol, binge-type eating is induced in non-food-deprived rats by providing limited access to an optional source of dietary fat: vegetable shortening. The protocol is simple and inexpensive, and the binge behavior is robust, reliable, and maintainable across extended periods of time. Two peptides that normally affect fat intake in rats have no effect on fat intake under limited-access conditions. However, recent results with a GABA(B) receptor agonist and with progressive-ratio responding suggest that the behavior induced by the limited-access binge protocol may share similarities with substance abuse. This protocol is designed to model the kind of excessive behavior that characterizes bingeing-related eating disorders and certain addictions.