One-child policy, weight status, lifestyles and parental concerns in Chinese children: a nationwide cross-sectional survey.

BACKGROUND/OBJECTIVES
China's one-child policy has been in place for 35 years, yet its impact on the differences of weight status including thinness and overweight/obesity, lifestyles, and parental concerns between only children (OC) and non-only children (NOC) were seldom discussed.

SUBJECTS/METHODS
A total of 62,444 children aged 6-17 years were recruited in 2013. Thinness and overweight/obesity were calculated from anthropometric measurements. Information on dietary consumption, dietary behaviors, physical activities (PA)-related behaviors, and parental concerns were obtained via questionnaires.

RESULTS
Overall, 68.6% of children were OC. The prevalence of thinness and overweight/obesity were 6.98% and 24.86% in OC, in contrast to 6.57% and 19.46% in NOC, respectively. In comparison with NOC, OC had more dietary intakes of vegetables, fruits, meat products, and sugar-sweetened beverages (SSBs). OC had better dietary behaviors including more regular breakfast, regular dairy products, less fried food, and less eating-out habits, but worse dietary behaviors including more SSBs and fast food intakes. Parents of OC showed more concerns toward their child's health, but the difference became nonsignificant after adjustment for parental education levels. Similar situations were also found in the differences of PA-related behaviors between OC and their counterparts.

CONCLUSIONS
More than two-thirds of the children were OC in this study. Notably, OC were more likely to have higher food intakes and behaved worse in certain dietary behaviors, and were at higher risks of overweight and obesity. There were no differences in the prevalence of thinness, PA-related behaviors, and parental concerns between groups.