Obesity and stature in adolescence and earnings in young adulthood. Analysis of a British birth cohort

Abstract

Objective: To examine the association between obesity and stature at various ages and earnings in young men and women at age 23 years.

Design: We estimated the effect of obesity on earnings by constructing a series of ordinary least-squares regression equations in which the dependent variable was the natural logarithm of hourly earnings at age 23 years. We report the coefficients for obese subjects compared with those for the nonobese subjects and for height while controlling for a number of other factors that are known to affect pay.

Setting: A birth cohort of 12,537 respondents at age 23 years from the National Child Development Study, which consists of all children born in England, Scotland, and Wales between March 3 and 9, 1958.

Outcome measure: Hourly earnings at age 23 years as it relates to obesity, as determined by the body mass index and stature measured as a continuous variable.

Results: Men and women who had been obese at age 16 years had significantly fewer years of schooling than did their nonobese peers. Obese women performed poorly on math and reading tests at ages 7, 11, and 16 years when compared with their nonobese peers. Regression analyses indicated no relationship between obesity at any age and earnings at age 23 years in males. In contrast, there was a statistically significant inverse relation between obesity and earnings in females, independent of parental social class and ability test scores of the child. Female adolescents who were in the top 10% of the body mass index at age 16 years earned 7.4% less (95% confidence interval, -11% to -3.8%) than their nonobese peers; those in the top 1% earned 11.4% less (-21% to -1.5%). The inverse relationship between obesity at 16 years of age and earnings persisted whether the adolescent female remained obese (-6.4% [-12.3% to -4.7%]) or moved into the nonobese category by age 23 years (-7.5% [-12.5% to -2.4%]). A positive relationship was found between height at age 16 years and earnings at age 23 years for men (but not for women) after controlling for social class and IQ.

Conclusions: This study demonstrates an inverse relationship between obesity at 16 years and earnings at age 23 years for British women; the magnitude of the relation is similar to that of other factors that predict earnings, such as gender, job training, and union membership. In the case of men, we found a positive relationship between height and subsequent earnings but no obesity effects.