I would do some pauses time to time or do fasting max 2 days per week or 10 days. I heard several diets, including the nutrition/separate diet one, which you have protein/starch/carbo/meat/fruit separate into days. It's also stated which to combine with which and in how many amount
A friend of mine went for a while eating as little food as possible, kind of an experiment to see how little food he really needed to survive... he's pretty crazy, but he was amazed by the intense fatigue that resulted.