Ads for weight-loss shakes, special formulas and pills to take, circulate our mainstream like crazy. It can be tempting to give into - you work day after day in the gym, sweating on the...

Picture it: Another diet fad comes along.

Buy these shakes, drink two a day, and lose 10 pounds instantly! 

So you buy the shakes, and you drink them, and you lose 6 pounds, which was exactly...