Well from what Ive read, they do help you, because just as in execercise or anything, once your body gets used to something it becomes good at it, then you have less efficient gains. Its the same with nutrition. If you eat the same kinds of foods or at least that give you the same basic nutrients and are too low on fats or some type of carbs, your body gets used to not processing them. Throwing them back in a day would jump start your body to start working hard again, in theory I guess. Someone who can probably get a little more technical with answer you soon!