Influence of proximities to food establishments on body mass index among children in China

Background and Objectives: Over the past two decades, food environment has changed, and the obesity and overweight rates have increased dramatically in China. Previous studies have suggested an association between food environment and obesity, while most studies were based on the data from developed countries, and few were conducted in developing countries. Methods and Study Design: The current study evaluated the influence of food establishments (distance to and types of grocery store, free market, restaurant, and food stall) on body mass index (BMI) in 348 children aged 6-17 years, surveyed in the 2009 and 2011 China Health and Nutrition Survey in nine provinces. Food establishments were assessed using geographic information system (GIS) data. Weight and height of children were directly measured. Results: Our longitudinal analysis suggested boys in the 2^nd quartile of the proximity to the nearest grocery store had higher BMI (by 1.6 kg/m², 95% CI, 0.07 to 3.24) as compared to those in the 1^st quartile, while girls in higher quartiles had lower BMI (-1.78 kg/m², 95% CI: -3.38 to - 0.18, 2^nd quartile; -1.62 kg/m², 95%: -3.22 to -0.01, 3^rd quartile) as compared to those in the 1^st quartile. Boys and girls in the 2^nd quartile of the proximity to the nearest Chinese restaurant had lower BMI (-1.69 kg/m², 95% CI: - 3.27 to -0.12; -1.76 kg/m², 95% CI: -3.26, -0.27, respectively) as compared to those in the 1^st quartile. Conclusions: Food environment may affect children's BMI in China, while the association is inconsistent with previous studies. Further research is needed.