And check out some of these articles:

Weight Watchers works? Not so much. 

Up to 2/3's of Dieters End Up Heavier - UCLA researchers analyzed 31 long-term studies, concluding diets don't work. (They found, in a 4-yr study of 19,000 healthy men, that the single biggest predictor of weight gain was a history of dieting!). They note people would be better off not dieting because it damages health. 

Dieting Makes Little Girls Fat - Five year old girls who diet end up fatter as they get older. 

Dieting Keeps Children Overweight - "Dieting to control weight is not only ineffective, it may actually promote weight gain." Based on a 2-year study ofmore than 16,000 U.S. boys and girls. Pediatrics.