Education Research Section (S Latham), Princeton University, Princeton, NJ.
Department of Psychology (JE Finch), University of Nebraska-Lincoln, Lincoln, Nebr.
Acad Pediatr. 2021 Mar;21(2):304-311. doi: 10.1016/j.acap.2020.11.021. Epub 2020 Dec 3.
Research shows that population-level rates of obesity, which rose dramatically from the 1970s through the mid-2000s, have since plateaued or even started to decline. However, overall improvements may mask differences in trends for different subgroups. For instance, obesity rates have continued to climb among low-income adolescents, leading to growing income-related gaps in obesity. By comparison, we know little about whether income-related disparities have also changed among elementary school children. To address this gap, we examined two cohorts of the Early Childhood Longitudinal Study - Kindergarten cohort, which followed children entering school in 1998 and 2010. We hypothesized that income-related disparities in obesity have also grown larger over time among young children.
We used data from nationally representative samples of children who entered kindergarten in 1998 and 2010. We documented rates of overweight and obesity from kindergarten through third grade, examined how rates differed for children from high- and low-income families, and tested whether income-related disparities changed over time.
Rates of overweight and obesity were 2 to 5 percentage points higher in the later cohort, and overall increases masked substantial variation by income. Specifically, these increases were driven by children in lower-income households, resulting in substantially larger income-related disparities in overweight and obesity in the later cohort.
As we hypothesized, income-related disparities in young children's obesity grew between 1998 and 2014. This suggests that efforts to curb increasing rates of obesity may have been more successful for higher-income families. We discuss potential mechanisms that may account for increasing disparities.
研究表明，从 20 世纪 70 年代到 21 世纪中期，肥胖率在人口层面上急剧上升，此后已趋于平稳，甚至开始下降。然而，总体改善可能掩盖了不同亚组趋势的差异。例如，低收入青少年的肥胖率继续攀升，导致肥胖的收入相关差距不断扩大。相比之下，我们对小学生中是否也存在与收入相关的差异变化知之甚少。为了解决这一差距，我们研究了《儿童早期纵向研究 - 幼儿园队列》中的两个队列，该研究跟踪了 1998 年和 2010 年入学的儿童。我们假设，随着时间的推移，肥胖的收入相关差距在幼儿中也会越来越大。
我们使用了 1998 年和 2010 年进入幼儿园的具有代表性的全国儿童样本数据。我们记录了从幼儿园到三年级超重和肥胖的发生率，检查了高收入和低收入家庭的儿童之间的发生率差异，并测试了收入相关的差异是否随时间变化。
后来的队列中，超重和肥胖的发生率高出 2 到 5 个百分点，整体增长掩盖了收入的巨大差异。具体来说，这些增长是由低收入家庭的儿童推动的，导致后来的队列中超重和肥胖的收入相关差距显著增大。
正如我们所假设的，儿童肥胖的收入相关差异在 1998 年至 2014 年间有所扩大。这表明，遏制肥胖率上升的努力可能对高收入家庭更为成功。我们讨论了可能导致差距扩大的潜在机制。
