Along with our country economy fast development, people's living standards improve, the obesity problem more and more serious, obese people in our country also has more and more proportion of the population. Study population obesity and health in our country, to promote the development of our country people's physical health is of great significance. First of all, this article obtains from the obesity problem in our country, studied the development of obesity, and obesity induced a series of disease, put forward the sport is simple, and the effect of the most obvious way to lose weight. Secondly, analysis of variance was used to study the impact of different sports to weight of significance, it is concluded that in jogging, sports dance, ball games, swimming and so on, the swimming for the effect of the most significant weight. Against swimming in this foundation, using discriminant analysis further research, identify the best swimming time standards for weight loss, and put forward: the best time to swim for 30 ~ 60 min/day, obviously the effect reducing weight, had a greater influence on the body shape, such as body weight, waist circumference, is one of the most suitable sports to lose weight.