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