Disease analysis: The difference between whole milk and skimmed milk is the fat content: the fat content of whole milk is about 3.0%. If whole milk is skimmed and the fat content is reduced to less than 0.5%, it becomes skim milk. If the fat content after skimming is above 0.5%, it is generally called reduced-fat milk. Compared to other foods, whole milk is not high in fat. Drinking one to two cups a day has little effect on your weight, and the fat-soluble vitamins in milk, such as vitamins A, D, and E, are generally found in fat. After skimming, these vitamins are also removed, so try to drink whole milk. People who are losing weight can choose skim milk, and patients with severe pancreatitis and other diseases can choose skim milk.