That's because they're not designed to work, they're designed to confirm to what people think will work. Losing weight is not a mystery: Take less calories in

That's because they're not designed to work, they're designed to confirm to what people think will work. Losing weight is not a mystery: Take less calories in than you burn and you will lose weight (simple, but 99% effective). To do this you need to eat healthy foods and get active. People don't want to do this. People want to eat crappy foods and sit around watching Grey's Anatomy (#93) and lose weight.