That's roughly equivalent to the amount the U.S. Federal Government spends on education each year. Dieting rarely works. Dieting forces your body into starvation mode. It responds by slowing down many of its normal functions to conserve energy. This means your metabolism actually slows down.
Dieters often miss out on important nutrients.
For example, dieters often don't get enough calcium, leaving them at risk for osteoporosis, stress fractures, and broken bones. When you restrict calories you restrict your energy, which in turn can restrict your brainpower. Medical studies indicate that people on diets have slower reaction times and a lesser ability to concentrate than people not on a diet. All of the stress and anxiety about food and weight that preoccupy dieters actually can consume a portion of a dieters' working memory capacity. Many studies and many health professionals note that patients with eating disorders were dieting at the time of the development of their eating disorder.