Ethnic differences in overweight and obesity between Han and Mongolian rural Chinese.

Background: Ethnic differences in the prevalence of obesity are known to exist. However, little is known about obesity in different ethnic rural Chinese. This study was designed to investigate the epidemiologic features of overweight and obesity in Han and Mongolian rural Chinese.
Methods: A cross-sectional survey was conducted during 2004-2006, which made use of a multistage cluster sampling method to select a representative sample in Fuxin county, Liaoning province, China. 36,154 Han people and 9236 Mongolian people aged > or =35 years were examined. At baseline, lifestyle and other factors were obtained. Overweight and obesity were defined according to the World Health Organization classification and Chinese criteria, respectively.
Results: Using WHO criteria, 21.3% of the Han people and 26.1% of the Mongolians had overweight or obesity (P < 0.001). The corresponding figure was 33.4% of the Han people and 40.3% of the Mongolians by Chinese criteria (P < 0.001). The prevalence of overweight was significantly higher in Mongolian people than Han people (P < 0.001). Multivariate logistic regression revealed that female gender, high levels of education and current drinking status were the common risk factors for Han and Mongolian overweight or obese participants, while age > or =65 years and current smoking status were the common protective factors. Below the age of 65 years, a positive association was observed between age and overweight or obesity in Han people, but not in the Mongolian people. High levels of physical activity as a protective factor and diabetes as a risk factor were shown in Han but not in Mongolian people.
Conclusions: There were ethnic differences in overweight and obesity between Han and Mongolian rural Chinese. These differences might be due to different factors between these two ethnicities such as age, physical activity and diabetes.