We divide the prevention of obesity into three levels: prevention of the occurrence of obesity, prevention of comorbidities caused by obesity, and prevention of the harm caused by comorbidities. Because it is more difficult to correct obesity once it occurs, prevention of obesity is particularly important. Generally speaking, the prevention of obesity needs to start from the cause of the occurrence of obesity. Prevention of obesity should mainly pay attention to the following aspects: 1, improve health awareness: fully understand the harm of obesity to the human body, understand people in infancy, adolescence, before and after pregnancy, menopause, old age, each age is prone to fat knowledge and prevention methods. Parents should assist children to control weight, careful to prevent future obesity. 2, a balanced and reasonable diet: the use of a reasonable diet, to achieve the daily three meals regularly and quantitatively, scientific arrangements for daily diet, such as diet is not greasy, not sweet and not too much, it is appropriate to increase the consumption of vegetables and coarse grains, less fat, sweet and thick, more vegetarian food, less snacks. 3, strengthen exercise: often participate in jogging, climbing, playing ball and other outdoor activities, not only can enhance physical fitness, make the body fit, but also prevent the occurrence of obesity. Weight loss of the population to pay attention to the speed of weight loss: mild obesity can lose 0.5 ~ 1.0kg per month, moderate obesity can lose 0.5 ~ 1.0kg per week. 4, regular normal life: to maintain good habits, according to the age of different reasonable arrangements for their sleep time, both to meet the physiological needs, but also can not sleep too much. 5, keep a good mood: good mood can make the physiological function of the body systems to maintain normal operation, to prevent obesity can play a role. Weight loss and slimming should start with balanced nutrition. When the body’s nutrition is balanced, excess nutrition is consumed, excluded from the body, insufficient nutrients daily to get the right amount of supplement, obesity naturally disappeared and maintain physical health. To achieve balanced nutrition, daily diet in all aspects need to pay more attention to the various types of food to eat every day to diversify, balanced, appropriate amount. Weight loss process, chocolate, fried food, dried fruit, cake, etc. is best to eliminate; egg yolk fat and calories are high, the intake of two per week is limited; daily selection of fresh skim or low-fat milk, meat to fish and seafood or lean beef, animal liver, as far as possible to steam, boiled instead of fried, fried, fried; staple food to a small amount of rice instead of fried rice or pasta, follow the principle of a small number of meals, chew slowly.