Fad diets sell the fantasy that 'this time it'll be different'. Other diets are high in protein, others have weird rules about combining certain foods, others about not combining certain foods. Needless to say, most fad diets aren't balanced, some even dangerous. I review many of them in my book. Although the authors often give impressive- sounding scientific rationales for their diets, the diets have no decent science behind them.
People do lose weight on fad diets.
If they're fad diets , they fail for the reasons I've just mentioned. But good diets fail, as well. Noted weight loss psychologist Kelly Brownell gave me permission to use his weight loss readiness quiz in my book. Its a great tool to measure you're state of readiness. If all you're ready to do is take a walk twice a week, then start there.