The 21-day diet is a significant reduction in energy calorie intake over a period of about 3 weeks, requiring no dinner every day for 21 days, and one day a week to take out a full day without eating, but drinking water without limiting the amount. The calorie intake will be significantly reduced, the weight will be 5-10 kg lower than the original, if the base weight of the heavier people will drop more, it is best to be accompanied by appropriate exercise, 30-60 minutes of exercise every day, such as playing badminton, cycling, brisk walking, doing exercises and other exercises, but also can take a medium-intensity physical activity. 21 days after the end of the attention to continue to adhere to a period of time, because the weight loss to Want to take the new weight as a tuning point, you need to continue to consolidate for about a month, otherwise it is easy to rebound.