In the beginning, eating was simple—consume three square meals a day and you’re done (thanks, Mom!). But then diets got more complicated. Instead of having proper meals, we now fit food in whenever we have time—and usually end up so famished by 3 P.M. that we’re stalking the office vending machine like zombies. You don’t need us to tell you that this is no way to stay healthy, but when it comes to losing weight and getting in shape, what is the proper eating regimen?