Losing weight is not a cure for life.

Reality check: you can never, ever, use weight loss to solve problems that are not related to your weight. At your goal weight or not, you still have to live with yourself and deal with your problems. You will still have the same husband, the same job, the same kids, and the same life. Losing weight is not a cure for life.

Phillip C. McGraw, The Ultimate Weight Solution

And neither are any of those other diets for longer life or fixing genetic code or whatever other quick fixes are claimed. Though we are living in a time of fad diets that is probably greater than anything since Battle Creek.