How long it takes to lose weight on a diet varies from person to person, depending on the level of dieting and the type of food being replaced. Usually dieting for weight loss can have significant results in 2-4 weeks, but it is not generally recommended as it is more harmful to the body. Diet control is the key to weight loss, but diet is also the source of what the body needs to ensure daily metabolism, so to diet properly for weight loss, replace foods with fewer calories and rich in dietary fiber. Some patients consume high-protein, high-calorie, high-fat, high-salt foods for replacement, although the daily intake is very small, but also can not achieve the purpose of weight loss. In addition, excessive dieting is not conducive to health, long-term irregular diet can lead to a decline in the body’s immunity, easy to rebound phenomenon, and even the more fat loss, there may be serious gastrointestinal dysfunctional diseases, serious anorexia. It is recommended that patients should lose weight healthily, carry out appropriate activities while controlling their diet, progress gradually, get enough sleep, have a happy mood, avoid being sedentary, avoid being too full and too hungry, and keep their weight within a reasonable range.