LBJ School of Public Affairs, University of Texas at Austin, 2315 Red River, Box Y, Austin, TX78712, USA.
Department of Sociology, St. Norbert College, Boyle Hall 454, 100 Grant Street, De Pere, WI 54115, USA.
Soc Sci Med. 2014 Mar;105:131-9. doi: 10.1016/j.socscimed.2014.01.004. Epub 2014 Jan 17.
More educated adults tend to have lower body mass index (BMI) and a lower risk of overweight and obesity. We contrast two explanations for this education gradient in BMI. One explanation is selection: adolescents with high BMI are less likely to plan for, attend, and complete higher levels of education. An alternative explanation is causation: higher education confers lifelong social, economic, and psychological benefits that help adults to restrain BMI growth. We test the relative importance of selection and causation using data from the National Longitudinal Survey of Youth, 1997 cohort (NLSY97), which tracks self-reported BMI from adolescence (age 15) through young adulthood (age 29). Ordinal regression models confirm the selection hypothesis that high-BMI adolescents are less likely to complete higher levels of education. Selection has primarily to do with the fact that high-BMI adolescents tend to come from socioeconomically disadvantaged families and tend to have low grades and test scores. Among high-BMI girls there is also some evidence that educational attainment is limited by bullying, poor health, and early pregnancy. About half the selection of high-BMI girls out of higher education remains unexplained. Fixed-effects models control for selection and suggest that the causal effect of education on BMI, though significant, accounts for only one-quarter of the mean BMI differences between more and less educated adults at age 29. Among young adults, it appears that most of the education gradient in BMI is due to selection.
受教育程度较高的成年人往往体重指数（BMI）较低，超重和肥胖的风险也较低。我们对比了两种解释 BMI 中这种教育梯度的理论。一种解释是选择：BMI 较高的青少年不太可能计划、参加和完成更高水平的教育。另一种解释是因果关系：高等教育赋予了成年人终身的社会、经济和心理益处，帮助他们控制 BMI 的增长。我们使用来自青年全国纵向调查（NLSY97）1997 队列的数据，检验了选择和因果关系的相对重要性，该数据跟踪了青少年（15 岁）到青年（29 岁）时期的自我报告 BMI。有序回归模型证实了选择假设，即高 BMI 青少年不太可能完成更高水平的教育。选择主要与以下事实有关：高 BMI 青少年往往来自社会经济地位较低的家庭，且成绩和考试分数往往较低。在高 BMI 女孩中，也有一些证据表明，教育程度受到欺凌、健康状况不佳和早孕的限制。大约一半高 BMI 女孩没有接受高等教育，这一现象仍无法解释。固定效应模型控制了选择因素，并表明教育对 BMI 的因果效应虽然显著，但仅占 29 岁时受教育程度较高和较低的成年人之间平均 BMI 差异的四分之一。在年轻人中，BMI 中的教育梯度似乎主要归因于选择。
