The effect of losing weight without eating or drinking for a week varies from person to person, but in general, you can lose about 5 pounds after a week, but it should be noted that this method of losing weight is not suitable for people who want to lose weight, because once eating is resumed, it will not only make your weight rebound, but also bring harm to your body during the dieting stage. Will cause malnutrition in the body. The operation of various organs of the body needs a lot of nutrients, such as protein, vitamins and amino acids, and most of these foods need to be taken from food. If the body doesn't eat for a week, it can't supplement these substances, which will easily lead to malnutrition in the body. When malnutrition occurs, it will lead to problems in the operation of the body's organs, and some will even cause more serious harm. It hurts the stomach. The stomach needs food to function and stay healthy. If you don't eat for a long time, your stomach will be empty. At this time, the gastric acid discharged from the stomach can not decompose food, and it will also harm the gastric mucosa. Over time, it will lead to stomach problems. Many people with stomach problems in life are mostly caused by not eating on time. If you want to lose weight, you must use correct and scientific methods to make your body lose weight healthily. Dieting may succeed in losing weight in a short time, but once it is resumed, it will rebound. If you don't eat for a week and only drink water to lose weight, you can lose at least 5- 10 kg. However, this method has a great influence on organs such as stomach and intestines, and it is easy to lead to malnutrition, hypoglycemia and insufficient blood supply.