Background Evidence of associations between dietary calcium, diary intakes and childhood overweight/obesity were limited, especially in China. Our aims were to investigate the prevalence of overweight/obesity among children and adolescents aged 7-15 years in Chengdu, China and to explore whether dietary calcium, dairy intakes were associated with overweight/obesity among Chinese children and adolescents.
Methods 1,738 children and adolescents aged 7-15 years were recruited in a cross-sectional study using cluster random sampling method. Information on dietary calcium and dairy intakes was collected using 24-hour dietary recall and a food frequency questionnaire. Height, weight and waist circumference were measured to calculate body mass index (BMI), body mass index standard deviation (BMI SDS) and waist-to-height ratio (WHtR). Overweight/obesity was defined based on the sex-age-specific BMI criteria of Working Group on Obesity in China (WGOC). Participants were grouped into 3 categories indicating lower, moderate and higher intakes of dietary calcium and dairy intakes, respectively. The associations between consumption of dietary calcium, dairy and BMI SDS, WHtR and the prevalence of overweight/obesity were analyzed among different age groups (7-9, 10-12, 13-15 y).
Results The prevalences of overweight/obesity in boys and girls were 11.92%/7.04% and 8.04%/6.30%, respectively. Among boys aged 7-9 years, those with higher consumption of dairy had the highest BMI SDS (p=0.01). Among boys aged 10-12 years, those with higher comsuption of dietary calcim had the lowest prevelance of overweight (p=0.02). Among boys aged 13-15 years, those with moderate dietary calcium intake had the highest WHtR (p=0.02). However, similar results were not observed among girls.
Conclusion Dietary calcium and dairy intakes seemed to be related to overweight/obesity in boys, but the associations were inconsistent among different age groups. Associations between consumption of calcium, dairy and overweight/obesity were not found among girls.