Eating disorder a given year. Anorexia affects about 0.4% and bulimia affects about 1.3% of young women in a given year. Up to 4% of women have anorexia, 2% have bulimia, and 2% have binge eating disorder at some point in time. Anorexia and bulimia occur nearly ten times more often in females than males. Typically, they begin in late childhood or early adulthood. Rates of other eating disorders are not clear. Rates of eating disorders appear to be lower in less developed countries. Bulimia nervosa is a disorder characterized by binge eating and purging, as well as excessive evaluation of one's
Hunger (motivational state) person's energy levels fall below a certain threshold, the sensation of hunger is experienced, which is the body's way of motivating the person to eat again. The set-point assumption is a negative feedback mechanism. Two popular set-point theories include the glucostatic set-point theory and the lipostatic set-point theory. The set-point theories of hunger and eating present a number of weaknesses. The positive-incentive perspective is an umbrella term for a set of theories presented as an alternative to the set-point theories of hunger and eating. The central assertion to the positive-incentive perspective is the idea that humans and other animals are