Take a second look at the foods you're eating. From personal experience, the most important thing is to watch your sugar intake; a lot of "healthy" foods are loaded with extra sugar, chemicals or other harmful ingredients you wouldn't have imagined. The more fresh, whole foods without ingreidents lists the better, but when lists are there read EVERY one, and if you don't know what's in it, don't eat it. Even real, fatty foods (i.e. organic butter) are less dangerous than artifical concauctions.