Do: Have three snacks a day
Last updated by Angela Haupt | January 02, 2013
Nutrisystem determines portions, prepares and delivers your meals, and tells you what to eat and when.
The Cookie Diet revolves around low-calorie cookies made with a secret "hunger-controlling" formula. There's no research to back it up.
The Mayo Clinic diet plan focuses on lifelong healthy eating. It's rated high in nutrition, safety, and diabetes, but only moderately effective for weight loss.