Weight regain during weight loss is considered to be due to unreasonable weight loss methods, weight loss plateau and increased muscle mass. 1. Unreasonable dieting: Failure to control diet, excessive intake of high-calorie foods, wrong dieting methods and poor lifestyle such as staying up late will all lead to weight regain. 2. Weight loss plateau: During the weight loss process, the body has to maintain the basic metabolism to avoid energy being completely depleted. When energy is depleted to a certain extent, the body will absorb calories, resulting in weight regain. 3. Increase in muscle mass: Exercise consumes energy resulting in a decrease in fat, and while fat is consumed, muscle increases. The water content of muscle tissue is higher than that of fat tissue, so weight regain will occur. During weight loss, it is important to have a scientific and reasonable weight loss program, maintain adequate sleep, and avoid excessive anxiety.