OBJECTIVETo examine the incidence of obesity and its modifiable risk factors in Chinese adults aged 35-74 years.

METHODSA total of 27 020 participants aged 35 to 74 years from two prospective cohort studies in China were followed up in the years of 2007 and 2008. Obesity and overweight were defined as body mass index ≥ 28.0, and 24.0-27.9 kg/m(2), respectively. Relative risks of obesity for risk factors were computed by using logistic regression.

RESULTSThe annual incidence rates of obesity and overweight were 6.97 ‰ and 24.83 ‰ in Chinese adults aged 35-74 years, respectively. Women had a higher incidence of obesity than men (7.74 ‰ vs. 6.10 ‰). Participants in northern China had a higher incidence than those in southern (9.29 ‰ vs. 5.10 ‰) part of the country. Adults in rural had a higher incidence than those in urban (7.28 ‰ vs. 6.52 ‰). After adjusting for the baseline variables, such as gender, age, geographic region, degree of urbanization, the relative risk for obesity was 0.82 (95% CI:0.68-0.99) for participants with ≥ 12 years' education, compared with those <12 years. Participants with middle income, less physical activity at work/housework or being retirees, consuming more red meat and scented tea etc, had higher risk of incidence of obesity. Participants who consumed milk and moderate amount of fruits, would show a lower risk of obesity.

CONCLUSIONThe incidence of obesity was 6.97 ‰ in Chinese middle and older adults. Our results underscored that the promotion of healthy lifestyle which include issues as increasing physical activity, consuming moderate amount of fruits and milk but less red meat, drinking less scented tea etc, could play key roles in obesity prevention and control among the Chinese adults, especially among people with low education level or with middle income.