RESUMO
Objective To investigate the trend of BMI among adults in Shaanxi Province from 2007 to 2015. Methods Data was obtained from China Chronic Disease and Risk Factor Surveillance from 2007 to 2015, in which a multistage clustering sampling was adopted to collect a provincially representative sample of adults in Shaanxi Province. BMI percentile(P5, P25, P50, P75, P95) and the prevalence of underweight, overweight and obesity was calculated with weight in each survey. Cochran-Armitage test was used to test trends across survey periods. Changes in BMI across survey years were compared by considering the sampling weight. Results The results of the surveillance indicated that the prevalence of underweight decreased while overweight and obesity increased among adults in Shaanxi province (Z=-14.70, P<0.001). We observed the highest increase in the prevalence of overweight and obesity among rural residents and residents aged from18 to 44. The mean BMI was estimated to increase 0.176(t=3.00, 95%CI：0.055-0.298， P=0.006) per year. We found no difference in overweight and obesity ( 2=0.196，P=0.459) between 2013 and 2015. Conclusions We note increases in overweight or obesity and a decrease in underweight among adults in Shaanxi Province. Those living in rural areas and aged from 18 to 44 led the highest increase in overweight and obesity.