Effects of fruits and vegetables intake and physical activities on the relationship between one-child and low height level classification

Objective To explore the relationship between one-child and low height level classification among children and adolescents, and the effects of fruits, vegetables and physical activities on this association, and to provide as cientific reference for probing into and improving the differences of their height level between one child and child with siblings. Methods Using stratified cluster sampling method, 93 primary and secondary schools in 7 provinces and cities in China were selected for physical examination and questionnaire surveys. A total of 40 978 primary and middle school students aged 7-17 were selected. A multilevel Logistic regression model was used to analyze. Results Univariate analysis found that being one-child was less likely to be classified as low height level ( OR = 0.63, 95%CI = 0.58-0.67); the multilevel model also found that the probability that one-child being at low height level was still lower ( OR = 0.78, 95% CI = 0.73-0.85), and daily vigorous-intensity physical activities ≥1 h ( OR = 0.92, 95% CI = 0.85-0.99) and daily vegetables and fruits intake ≥5 servings ( OR = 0.83, 95% CI = 0.75-0.92) could also reduce the probability of being at low height level. Hierarchical analysis found that when vegetables and fruits intake and physical activities time were sufficient, there was no longer a significant difference in the height level classification between one-child and child with siblings ( P > 0.05). Conclusion Being one-child could be a protective factor for the height level classification of children and adolescents. Adequate intake of vegetables and fruits and time of vigorous-intensity physical activities could fill the gap of height level classification between of being one-child and child with siblings. Effective behavioral intervention measures should be taken to protect the healthy growth of height among children and adolescences. 【摘要】 目的 探讨独生子女与儿童青少年低身高发育等级的关联以及果蔬摄人和体力活动对该关联的影响, 为探究和 改善独生与非独生子女身高发育等级的差异提供科学依据。 方法 采用分层整群抽样方法, 在中国7个省市抽取93所中 小学校40 978名7〜17岁学生进行体格检查和问卷调查, 采用多水平模型进行统计学分析。 结果 单因素分析发现, 独生 子女处于低身高发育等级的概率更低 ( OR = 0.63,95% CI =0.58~0.67);多水平模型发现, 独生子女处于低身高发育等级的 概率依然较低 ( OR = 0.78,95% CI = 0.73~0.85), 且每日中/高等体力活动时间≥1 h ( OR = 0.92,95% CI =0.85~0.99)和每日 蔬菜水果摄人量≥5份 ( OR = 0.83,95% CI = 0.75〜0.92)也可降低处于低身高发育等级的概率。分层分析发现, 果蔬摄人和 体力活动充足时, 独生与非独生子女身高发育等级差异均无统计学意义( P 值均>0.05)。 结论 独生子女是儿童青少年身 高发育可能的影响因素, 充足的果蔬摄人和体力活动可改善非独生与独生子女身高发育等级的差距。应采取有效的行为 干预措施, 保护儿童青少年身高健康发育。