A COMPARATIVE STUDY OF THE ETIOLOGY AND INTERVENTION OPTIONS OF CHILDHOOD OBESITY IN CHINA AND THE UNITED STATES USING SYSTEMS SCIENCE APPROACHES

Objectives: The overall goal of this research project is to study the etiology and intervention options of childhood obesity through comparative research between China and the US. Three specific aims are: 1) examine the relationship between Western fast food consumption (FFC) and childhood obesity; 2) examine the effects of social norms on school children’s weight status and food behavior; 3) assess the effects of fiscal policies on children’s beverage and energy intake. Methods: The three aims are presented in three separate papers. In the first paper, using the nationwide China Health Nutrition Survey data, Heckman’s two-stage selection model and quantile regression models were fitted. In the second paper, agent-based models (ABMs) were developed and linked with empirical longitudinal data collected in China and in the US. In the third paper, system dynamics models were built to assess the sugar-sweetened beverage (SSB) tax effects in China and the US. Results: Household income was negatively associated with the likelihood of Western FFC decisions, while positively associated with Western FFC frequency in China. The ABM simulation study suggest that, in China, social norms may lead to a 0.05 (kg/m2) BMI increase for one unit of BMI below the social average, and a 0.045 (kg/m2) decrease for one unit of BMI above the social average. In the US, corresponding social norm effects were 0.025 (kg/m2) and 0.015 (kg/m2) respectively. The third essay indicates, in China, a 20% tax on SSB might cause an initial 11.5 kcal/d reduction in energy intake from beverage consumption; in a 10-year period, the net reduction of average daily energy intake compared to the level before taxing would decrease to 4 kcal/d. Similarly, in the US, there will be a net reduction of 36 kcal/d initially, with the reduction decreasing to 10 kcal/d over a 10-year period. Subsidizing bottled water consumption could be more effective than SSB taxes. Conclusions: China has its own unique patterns of childhood obesity, while sharing some features with the US. Policies that limit FFC, promote healthy social norms and subsidize bottled water consumption are needed in fighting childhood obesity