Clinical Obesity Among Chinese Adults: Prevalence, Multimorbidity Burden, and Associations with Physical Activity

Background/Objectives: The Lancet Diabetes & Endocrinology Commission recently proposed distinguishing preclinical obesity from clinical obesity, in which excess adiposity is accompanied by obesity-related disease. Using data from the China Nutrition and Health Surveillance 2015, we estimated the prevalence and comorbidity burden of clinical obesity among Chinese adults and further explored the association between physical activity and clinical obesity. Methods: This cross-sectional study included adults aged 18-79 years from the China Nutrition and Health Surveillance 2015 (N = 180,480). Excess adiposity was identified using body mass index, waist circumference, and waist-to-height ratio. Participants were classified as having no obesity, preclinical obesity, or clinical obesity, defined as excess adiposity plus at least one obesity-related comorbidity. We estimated the prevalence of clinical obesity overall and across sociodemographic subgroups. In secondary analyses, we examined the association of physical activity (MET-min/week) with clinical obesity prevalence and ordered obesity status using fully adjusted proportional-odds models. Results: Overall, 33.9% of adults had excess adiposity, and 26.9% met the criteria for clinical obesity. The prevalence of clinical obesity increased from 15.3% among adults aged 18-39 years to 33.3% among those aged ≥60 years and varied across sociodemographic subgroups. Among individuals with clinical obesity, dyslipidemia, hypertension, and diabetes were the most common comorbidities, indicating a substantial cardiometabolic burden. Higher physical activity was associated with a lower prevalence of clinical obesity and lower odds of more severe ordered obesity status. Conclusions: Clinical obesity affects more than one quarter of Chinese adults and is associated with a substantial cardiometabolic burden. Higher physical activity was associated with a lower prevalence of clinical obesity and less severe obesity status. These findings provide nationally relevant evidence to inform prevention and clinical management in China.