Alas, a Blog discusses weight loss:

1) No weight-loss diet has every been scientifically shown to produce substantial long-term weight loss in any but a tiny minority of dieters.

2) Whether or not a weight-loss diet “works,” people who go on weight-loss diets are likely to die sooner than those who maintain a steady weight or who slowly gain weight.

3) For fat people (or anyone else) concerned with their health, the best option is probably moderate exercise and eating fruits and veggies, without concern for waistlines. In other words, Health At Every Size (HAES).

4) The model on which most weight-loss diets are based - in which fat people eat like fat people and must learn to eat like non-fat people - is probably a myth.