The reason for this is simple: Whenever you eat a food containing complex carbohydrates as well as fiber and other nutrients, this food is digested slowly and only a minimal amount of insulin is needed to convert the sugar into glucose that will be gradually released into your bloodstream. The key component here is the fiber—it’s very difficult to eat a lot of fiber-rich food in one sitting, as your body will rebel! Portion control throughout the day will keep your digestive system working at maximum efficiency.