What is the primary factor that characterizes bulimia nervosa?

The primary factor that characterizes bulimia nervosa is a repeated cycle of binge eating and purging. Binge eating refers to consuming an excessive amount of food in a short period, accompanied by a sense of loss of control. Purging involves behaviors such as self-induced vomiting, excessive exercise, misuse of laxatives, or diuretics, with the intention to eliminate the calories consumed during the binge.