Shrinking due to corpulence? BMI in childhood predicts subsequent linear growth among US children and youth, 1963-1970.

While the USA is one of the most opulent countries, its population is not among the tallest but is among the most corpulent. This short report investigates the association between body mass index in childhood and subsequent change in height-for-age at the individual level, based on data from the National Health Examination Study (1963-1970). A sub-sample of participants in this survey was measured twice at intervals between 2.3 and 4.4 years, and assessed bone age can be used to account for differences in maturation at baseline. Regression results indicate that a BMI-for-age above the 85th percentile is associated with a reduction in growth by 0.03-0.06 height-for-age standard deviations per year, or roughly 1 cm within 4 years. An inefficiently high nutritional status in childhood may thus jeopardize subsequent linear growth. However, the trans-Atlantic height gap is considerably larger than what this empirical relationship could predict.