Meal replacement refers to the partial or total replacement of dinner. Meal replacement is low in energy, high in fiber and easy to satiate. Meal replacement powder, for example, is often used in konjac flour. Three of the seven nutrients the human body needs every day provide energy for the human body: protein, fat and carbohydrates, of which only fat and carbohydrates can make people fat; The other four nutrients are water, minerals, vitamins and dietary fiber, of which water is the main component of the body and the carrier of nutrients and metabolites, and the other three cannot make people fat. That is, meal replacement uses low energy and high fiber instead of dinner, so that energy intake is less than consumption. At present, the methods or products adopted by some people can not fully meet the daily normal needs of the human body, so long-term use is likely to lead to nutritional deficiency, dizziness, palpitation, hair loss, hypoglycemia and so on. The body function is very strange. When the human body lacks energy intake, it often calls muscle glycogen or even decomposes muscle to supply energy first, so many dieters try to lose weight by dieting or meal replacement. In this way, the muscles that can consume the most energy are also reduced, resulting in a decline in basal metabolic rate, which is easy to rebound quickly after eating normally.