$18 Not for the half-hearted, this diet allows absolutely no cheat days (Squander? start over). On the bright side, its only 30 days and yields amazing results, according to users. Its pages are full of chef-developed recipes, a step-by-step game plan to breaking unhealthy habits, and motivational sound bites like this one: Dont you dare tell us this is hard. Quitting heroin is hard. Beating cancer is hard. Drinking your coffee black. Is. Not. Hard. Good luck!