Krølner Rikke, Due Pernille, Rasmussen Mette, Damsgaard Mogens Trab, Holstein Bjørn E, Klepp Knut-Inge, Lynch John
Institute of Public Health, University of Copenhagen, Denmark.
Soc Sci Med. 2009 Apr;68(8):1416-24. doi: 10.1016/j.socscimed.2009.01.022. Epub 2009 Feb 27.
It is often found that adolescents eat too little fruit and vegetables. We examined the importance of school for 11-year-olds' daily intake measured by food frequency- and 24-h recall questionnaires in Danish data from the European 2003 Pro Children Survey. Multilevel logistic regression analyses included matched student-parent-school questionnaire data (N=1410) from a random sample of 59 schools and were conducted for fruit and vegetables separately: 1) without explanatory variables, to decompose the between-school and within-school variance; 2) with individual level covariates (socioeconomic position, parental intake, etc.) to examine if the between-school variance was attributable to different student compositions of schools; and 3) with individual- and school-level covariates (school availability of fruit/vegetables and unhealthy food) to examine the effect of context. Additional analyses stratified by gender and home availability of fruit/vegetables examined if school food availability influenced subgroups differently. Between-school variations were quantified by intra class correlations and median odds ratios. We found that 40% of the students ate > or = 200 g fruit/day and 25% ate > or = 130 g vegetables/day. Most of the total variance in students' intake occurred at the individual level (93-98%). There were larger between-school variations in vegetable intake than in fruit intake. Fruit and vegetable consumption clustered within schools to a larger degree for boys than girls. The between-school variance did not differ by home availability. Boys and students from high availability homes consumed more fruit and/or vegetables if enrolled in schools with access to fruit/vegetables and unhealthy food or contrarily with no food available versus schools with only fruit/vegetables available. The small school-level effects on 11-year-olds' fruit and vegetable intake imply that family level interventions may be more important and that the success of school interventions will rely on the degree of parental involvement.
人们经常发现青少年摄入的水果和蔬菜过少。我们在2003年欧洲儿童调查丹麦数据中，通过食物频率问卷和24小时回顾问卷，研究了学校因素对11岁儿童每日摄入量的重要性。多层次逻辑回归分析纳入了来自59所学校随机样本的匹配学生-家长-学校问卷数据（N = 1410），并分别对水果和蔬菜进行分析：1）不使用解释变量，以分解学校间和学校内的方差；2）使用个体层面的协变量（社会经济地位、家长摄入量等），以检验学校间方差是否归因于学校不同的学生构成；3）使用个体和学校层面的协变量（学校水果/蔬菜及不健康食品的可获得性），以检验环境因素的影响。按性别和家庭水果/蔬菜可获得性进行分层的额外分析，检验了学校食物可获得性对不同亚组的影响是否不同。学校间差异通过组内相关系数和中位数优势比进行量化。我们发现，40%的学生每天摄入≥200克水果，25%的学生每天摄入≥130克蔬菜。学生摄入量的总方差大部分发生在个体层面（93 - 98%）。蔬菜摄入量的学校间差异大于水果摄入量。男孩的水果和蔬菜消费在学校内的聚集程度高于女孩。学校间方差不因家庭可获得性而有所不同。如果就读于有水果/蔬菜及不健康食品供应的学校，或者相反，就读于没有食物供应的学校，而不是只有水果/蔬菜供应的学校，来自高可获得性家庭的男孩和学生摄入更多的水果和/或蔬菜。学校层面因素对11岁儿童水果和蔬菜摄入量的影响较小，这意味着家庭层面的干预可能更为重要，且学校干预的成功将依赖于家长参与的程度。
