The one-meal-a-day diet is a well-known weight loss method, but it is also quite harmful to health. The one-meal-a-day diet is especially harmful to the stomach because it causes the stomach to be in a state of emptying for a long time, which makes it very easy to develop atrophic gastritis and even induce the occurrence of diabetes and gastric ulcers. The one-meal-a-day diet does not ensure that the body needs energy, protein, carbohydrates, fat, vitamins and other nutrients, which can easily cause a malnutrition for a long time, leading to diseases such as anemia caused by malnutrition.