I'm sure it will work, but I'm afraid you can't hold on. It is necessary to eat some fruits and vegetables and drink some milk. You are seriously overweight, you must seldom exercise, and your physical fitness must be very poor. If you don't eat at all in a short time, it is likely to cause physical discomfort and even life-threatening. What should I do after 7 days, and then restore my previous eating habits? This is much more than what you have lost. For ordinary people, losing weight is a long-term process. Reasonable diet and moderate exercise can achieve results all year round.