Department of Economics, University of Munich, Ludwigstrasse 33/IV, 80539 Munich, Germany.
Am J Hum Biol. 2010 Sep-Oct;22(5):631-8. doi: 10.1002/ajhb.21055.
The trend in the body mass index (BMI) values of the US population has not been estimated accurately because the time series data are unavailable and the focus has been on calculating period effects.
To estimate the trend and rate of change of BMI values by birth cohorts stratified by gender and ethnicity born 1882-1986.
We use loess additive regression models to estimate age and trend effects of BMI values of US-born black and white adults measured between 1959 and 2006. We use all the National Health Examination Survey and National Health and Nutrition Examination Survey data.
The increase in BMI was already underway among the birth cohorts of the early 20th century. The rate of increase was fastest among black females; for the three other groups under consideration, the rates of increase were similar. The generally persistent upward trend was punctuated by upsurges, particularly after each of the two world wars. The estimated rate of change of BMI values increased by 71% among black females between the birth cohorts 1955 and those of 1965 is indicative of the rapid increases in their weight.
We infer that transition to postindustrial weights was a gradual process and began considerably earlier than hitherto supposed.
由于缺乏时间序列数据，且研究重点一直放在计算周期效应上，因此未能准确估计美国人口体重指数（BMI）值的趋势。
按性别和种族对出生队列进行分层，估计 1882-1986 年出生的美国人群 BMI 值的趋势和变化率。
我们使用局部加权回归模型来估计 1959 年至 2006 年期间测量的美国黑人和白人成年人 BMI 值的年龄和趋势效应。我们使用了所有的国家健康检查调查和国家健康和营养检查调查数据。
20 世纪初出生的队列中 BMI 的增长已经开始。黑人女性的增长率最快；对于其余三个考虑的群体，增长率相似。普遍持续上升的趋势被两次世界大战后的上升所打断。BMI 值的估计变化率在黑人女性中增加了 71%，这表明她们的体重迅速增加。
我们推断，向后工业化体重的转变是一个渐进的过程，比此前认为的要早得多。
