Objective: The aim of this study was to evaluate trends in BMI and the prevalence of overweight (BMI > or = 25 kg/m(2)) and obesity (BMI > or = 30 kg/m(2)) between 1991 and 1999-2000 among Chinese adults.
Methods and procedures: In this study, two population-based samples of Chinese adults aged between 45 and 79 years (n = 7,858 during each period), and comparable in the distributions of age, gender, degree of urbanization, and region (North/South) were used. Height and weight were measured using identical procedures at each period, and BMI was calculated as weight (in kilogram) divided by height (in square meter).
Results: From 1991 to 1999-2000, the mean BMI increased from 21.8 to 23.4 kg/m(2) among men and from 21.8 to 23.5 kg/m(2) among women (each P < 0.001). Among men, the prevalence of overweight and obesity increased from 9.6 and 0.6%, respectively, in 1991 to 20.0 and 3.0%, respectively, in 1999-2000 (each P < 0.001). Among women, the prevalence of overweight and obesity increased from 14.5 and 1.8%, respectively, in 1991 to 26.5 and 5.2%, respectively, in 1999-2000 (each P < 0.001). The prevalence of overweight and obesity increased in all age groups, in rural and urban areas, and in North and South China, with greater relative increases in obesity among older age groups, South China, and rural areas (P interaction < 0.05).
Discussion: Overweight and obesity increased tremendously during the 1990s in China. These data underscore the need for national programs in weight maintenance and reduction, to prevent obesity-related outcomes in China.