Obesity, not only is a risk factor for chronic diseases such as coronary heart disease and diabetes, but also brings huge health insurance expenses. At a time when overweight and obesity have become important public health problems in China, how to manage weight scientifically has become a very urgent need. Starting from 2015, the Nutrition and Metabolic Management Branch of the China Association for the Promotion of Healthcare International Exchange, together with nearly 100 nutrition experts nationwide, prepared the Expert Consensus on Medical Nutrition Treatment of Overweight/Obesity in China (2015). The consensus analyzes and recommends common methods and common problems of medical nutrition weight reduction, and also gives professional advice on medical weight reduction for four special groups of people. Six recommended methods of medical nutrition for weight reduction: 1. Energy-limited balanced diet: It refers to a dietary pattern that restricts energy intake while ensuring basic nutritional needs, and the ratio of macronutrient energy supply should be in line with the requirements of balanced diet. It can take three forms: ① Decrease the target intake by a certain percentage, 30%~50%. ②Reduction of about 500kcal per day on the basis of the target intake. ③ Daily energy supply 1000~1500kcal, i.e. low energy diet. 2. High protein diet: A dietary pattern in which the daily protein intake exceeds 20%~40% of the total daily energy (or 1.2-1.5g/kg/d), but does not exceed 30% of the total daily energy (or 2.0g/kg/d). Since patients with chronic kidney disease (CKD) may have increased kidney burden due to high protein diet, it is recommended to choose high protein diet carefully. 3. Light fasting diet: or intermittent fasting, generally adopting a “5+2” – that is, eating normally 5 days a week and consuming 1/4 of the usual energy (about 500kcal/d for women and 600kal/d for men) on the other two days (non-consecutive). )-a dietary pattern. In addition, a 2014 Meta-analysis on type 2 diabetes mellitus (T2DM) prevention found that light fasting can be effective in weight loss and prevention of T2DM.(I secretly tell you that Professor Chen Wei himself is also using this diet pattern.) 4, exercise therapy: the impact of exercise on weight loss depends on the type, intensity, time, frequency and total amount of exercise. The “consensus” kind of recommended exercise for adults are: ① aerobic exercise: effective to improve cardiorespiratory function, is the core exercise to reduce visceral fat. ②Resistance exercise: more effective for improving lean body mass (fat loss weight). ③ Aerobic combined with resistance exercise: more effective for weight loss. ④High-intensity interval training (HITT): can be recommended as a time-saver, fat loss effect does not achieve similar benefits of continuous aerobic exercise. 5.Cognitive-behavioral and psychological interventions: Through adjusting the living environment and psychological state of obese/overweight patients, helping them understand and recognize obesity and its hazards, mastering the scientific methods of weight management and making behavioral changes. Interventions include: self-monitoring, controlled eating, stimulation control, cognitive reconstruction and relaxation techniques, which, together with physical activity and diet modification, can significantly reduce body weight. Behavioral interventions longer than 6 months are more effective and are equally important for weight maintenance after weight loss. 6.Maintenance after weight loss treatment: After medical nutrition weight loss treatment, weight loss maintenance is very important, but very difficult. A series of studies in recent years found that the body exists a variety of mechanisms to regulate energy balance in order to maintain the relative stability of their own weight. One year after the end of the weight loss program, most people will regain 30% to 35% of their lost weight, and after 4 years, they basically return to their pre-loss weight level. When maintaining weight loss, lifestyle and behavioral interventions are critical, and energy-restricted diets should be preferred. Weight management of four special groups of people: 1, children / adolescents: ① newborn period should be breastfeeding as far as possible, and appropriate to extend the breastfeeding time to reduce the risk of obesity in childhood. ②Strictly control the intake of snacks, especially snacks with high sugar content and carbonated beverages, and control the intake of high glycemic index (GI) foods in carbohydrates. ③Increase the intake of dietary fiber in an appropriate amount. 2, peri-pregnancy: In 2009, the Institute of Medicine (IOM) based on the incidence of maternal and infant adverse pregnancy outcomes, determined the recommended range of weight gain during pregnancy: 0.5 to 2 kg in early pregnancy, 7 to 11.5 kg in overweight women, and 5 to 9 kg in obese women. The dietary energy plan should be individualized according to height, weight, gestational age and activity level. 3, polycystic ovary syndrome: the prevalence of polycystic ovary syndrome (PCOS) in women aged 19 to 45 in China is about 5.6%, of which the incidence of obesity is 30% to 70%. Compared with normal weight PCOS women, all metabolic and reproductive indicators are decreased in obese PCOS patients. For obese PCOS patients, lifestyle interventions (diet, exercise and behavioral interventions) are more effective than pharmacotherapy, and energy-restricted diets are preferred. 4, combined metabolic syndrome: metabolic syndrome (MS) is obesity / overweight as the center with a series of metabolic disorders of the syndrome. Lifestyle interventions, including physical exercise, intensive nutritional counseling, behavioral education, psychological guidance and group support in addition to dietary treatment, are the basic treatment for patients to reduce weight. To effectively achieve lifestyle interventions, a multidisciplinary intervention steering group including clinicians, nutritionists, psychological counselors, and fitness trainers should be established. The medical weight reduction program should follow a step therapy: 1.: Patients with BMI 24-28 (kg/m2) and excessive waist circumference should be given diet therapy, exercise therapy, psychotherapy, behavioral interventions and health education. 2.：Patients with BMI 28～35(kg/m2), waist circumference exceeding the standard, or with risk factors, should be supplemented with drug therapy in addition to the above treatment. 3.：BMI>40(kg/m2), or BMI≥35(kg/m2) with risk factors, or patients with obesity-related complications, in addition to the above treatments, surgery should also be considered.