The influence of the built environment on human health has attracted increasing attention. Given that the elderly have been an integral part in China, the built environment not only influences their health, but also influences the life and work of their children, thus resulting in social problems. Based on questionnaire obtained data on the elderly people in Chongqing, an ordinal multi-categorical regression model is established to analyze the influence of built environment on the leisure and physical activities(especially walking) that the elderly participated in, and the influence on their Body Mass Index(BMI). The results show that, in addition to age and preference for high-calorie diet, whether there is convenient access to leisure and fitness places from where they live, and the corresponding distance in-between are significantly related to the BMI of the elderly. Particularly, the best distance range is less than 1,000 m, within which leisure and fitness places have significant impact on the BMI of the elderly and the influence shows distance decay. In the last section of this paper, according to the conclusion, proposals are put forward for the optimization of the built environment.
