The calories of fruits are lower than those of staple foods, mainly because their nutrients are different, and water is only one of them. The ingredients that form calories in food are mainly fat, protein, starch, glucose and other substances! Staple foods, such as meat, are rich in nutrients such as fat and protein, and rice is mainly starch, carbohydrates and inorganic salts. When carbohydrates and starch are decomposed, glucose is formed, which is the necessary energy to provide heat. The main components of fruit are water, fructose, vitamin C, dietary fiber and other nutrients. Compared with the fat needed to provide calories in staple food, protein, starch, glucose and other substances are few and far between! Of course, moisture content is also an important factor. The higher the moisture content, the lower the calories will be! So the calories of fruit are much lower than those of staple food.