It is not reasonable to eat an apple for breakfast, because breakfast should provide the most basic calories and nutrients for the morning work, study and life, and the nutrients of apple are mainly carbohydrates, that is, sugar, and its calories are very low, far from being able to meet the needs of a morning. A reasonable breakfast should include three parts, the first is the source of carbohydrates, mainly staple foods, such as bread, buns, porridge, cakes and the like, and then should include high-quality protein, such as milk, yogurt, eggs, soy milk, lean meat, and finally there should be some vegetables, so that it is a more balanced breakfast with the specific amount of about two slices of bread, and then take a cup of eggs milk, and a small amount of vegetables.