Drinking milk on an empty stomach has many disadvantages. Because it is on an empty stomach, the milk consumed cannot be fully enzymatically decomposed, and the protein in the nutrients will be quickly converted into energy consumption, and the nutrients cannot be well digested. absorb. Some people may also experience abdominal pain and diarrhea. This is because their bodies produce little or very little lactase. If they drink a lot of milk on an empty stomach, the lactose in the milk cannot be digested in time and is decomposed by bacteria in the intestines to produce a large amount of lactose. Gas and acid stimulate intestinal contraction, causing abdominal pain and diarrhea. Therefore, it is best to eat something before drinking milk, or drink milk while eating food to reduce the concentration of lactose and facilitate the absorption of nutrients.