Hooked on weight control: An economic theory of anorexia nervosa and its impact on health and longevity.

In this paper, I integrate a theory of body image, weight control, and addiction in a life cycle model with health deficit accumulation in order to explain the phenomenon of anorexia nervosa and its impact on health and longevity. Individuals consume normal goods and foods and can work off excess calories with physical exercise. There exists a healthy body mass index and deviations from it increasingly cause health deficits due to obesity or underweight. There exists also a subjective target weight and being heavier than target weight causes a loss of utility from body image. Anorexia is initiated in individuals who are particularly successful in weight control and prone to addiction. Addiction to weight control motivates anorexic individuals to perpetually adjust their target weight downwards and to eat less and exercise more. With declining weight, health deficits accumulate faster and mortality risk rises. I calibrate the model to an average American woman with bmi 28. Due to weight loss addiction, the bmi declines to a level of 15 and causes an expected loss of 15 years of life. I also discuss potential therapies and recovery from the disease.