School of Sport Exercise and Health Sciences, Loughborough University, Loughborough, UK.
UCL Institute Sport Exercise Health , Division Surgery Interventional Science, London, UK.
BMC Med. 2021 Apr 21;19(1):96. doi: 10.1186/s12916-021-01969-8.
Most studies on secular trends in body mass index (BMI) are cross-sectional and the few longitudinal studies have typically only investigated changes over time in mean BMI trajectories. We aimed to describe how the evolution of the obesity epidemic in Great Britain reflects shifts in the proportion of the population demonstrating different latent patterns of childhood-to-adulthood BMI development.
We used pooled serial BMI data from 25,655 participants in three British cohorts: the 1946 National Survey of Health and Development (NSHD), 1958 National Child Development Study (NCDS), and 1970 British Cohort Study (BCS). Sex-specific growth mixture models captured latent patterns of BMI development between 11 and 42 years. The classes were characterised in terms of their birth cohort composition.
The best models had four classes, broadly similar for both sexes. The 'lowest' class (57% of males; 47% of females) represents the normal weight sub-population, the 'middle' class (16%; 15%) represents the sub-population who likely develop overweight in early/mid-adulthood, and the 'highest' class (6%; 9%) represents those who likely develop obesity in early/mid-adulthood. The remaining class (21%; 29%) reflects a sub-population with rapidly 'increasing' BMI between 11 and 42 years. Both sexes in the 1958 NCDS had greater odds of being in the 'highest' class compared to their peers in the 1946 NSHD but did not have greater odds of being in the 'increasing' class. Conversely, males and females in the 1970 BCS had 2.78 (2.15, 3.60) and 1.87 (1.53, 2.28), respectively, times higher odds of being in the 'increasing' class.
Our results suggest that the obesity epidemic in Great Britain reflects not only an upward shift in BMI trajectories but also a more recent increase in the number of individuals demonstrating more rapid weight gain, from normal weight to overweight, across the second, third, and fourth decades of life.
大多数关于体重指数 (BMI) 随时间变化的研究都是横断面研究，而少数纵向研究通常仅调查了 BMI 轨迹随时间的变化。我们旨在描述英国肥胖流行的演变如何反映出人群中表现出不同儿童期到成年期 BMI 发展潜在模式的比例的变化。
我们使用来自三个英国队列的 25655 名参与者的 pooled 系列 BMI 数据：1946 年全国健康与发展调查 (NSHD)、1958 年全国儿童发展研究 (NCDS) 和 1970 年英国队列研究 (BCS)。性别特异性增长混合模型捕捉了 11 至 42 岁之间 BMI 发展的潜在模式。这些类别是根据其出生队列组成来描述的。
最好的模型有四个类别，对两性来说都大致相似。“最低”类别（57%的男性；47%的女性）代表正常体重亚人群，“中间”类别（16%；15%）代表那些可能在成年早期/中期发展为超重的亚人群，而“最高”类别（6%；9%）代表那些可能在成年早期/中期发展为肥胖的亚人群。剩下的类别（21%；29%）反映了一个亚人群，其 BMI 在 11 至 42 岁之间迅速“增加”。与 1946 年 NSHD 的同龄人相比，1958 年 NCDS 的两性都更有可能处于“最高”类别，但没有更大的可能性处于“增加”类别。相反，1970 年 BCS 的男性和女性患“增加”类别的几率分别为 2.78（2.15，3.60）和 1.87（1.53，2.28）。
我们的研究结果表明，英国的肥胖流行不仅反映了 BMI 轨迹的向上转移，还反映了在生命的第二、第三和第四个十年中，更多的人表现出更快的体重增加，从正常体重到超重。
