Incidence of Overweight and Its Predictors in Adults after 10 Years of Follow-up: Yazd Healthy Heart Project

Background: Obesity and overweight are important public health problems which are rapidly growing throughout the world. This study aims to provide 10-year incidence estimates of obesity and overweight in adults along with their risk factors in an Iranian adult population. Methods: This cohort study was conducted within the framework of the Yazd Healthy Heart Project (YHHP) throughout phases from 2005-2006 to 2015-2016 among urban adult population. The participants comprised of 1000 males and 1000 females aged 20-74 years from urban areas of Yazd. Cox proportional hazards model was used to examine the potential risk factors for obesity and overweight. Results: A total of 2000 participants aged 47.09 ± 16.97 years and body mass index (BMI) of 21.99 ± 2.21 kg/m2 were entered in this study at baseline. After 10 years of follow-up, the cumulative incidence of overweight for the entire population was 38.6% (41.6% in women and 36.8% in men). Furthermore, the 10-year cumulative incidence of obesity was 14.8% in the population (20.8% for women and 10.5% for men). Female participants showed a significantly higher incidence rate compared to males either for obesity or overweight. Regarding risk factors, there was a significant association between non-smoking (HR= 1.54, 95% CI: 1.06-2.25), socio-economic status (HR= 1.82, 95% CI: 1.13-2.94), and education (HR= 1.56, 95% CI: 1.14-2.13) with overweight (P < 0.05). Conclusion: This study revealed the incidence rate of obesity and overweight is significantly high in adult population of Yazd, Iran especially in women. The most important predictors of overweight seem to be smoking, lower socio-economic status, and education.