Comparable global data on health and nutrition of school-aged children and adolescents
are scarce. We aimed to estimate age trajectories and time trends in mean height and mean
body-mass index (BMI), which measures weight gain beyond what is expected from height
gain, for school-aged children and adolescents

FINDINGS: We pooled data from 2181 population-based studies, with measurements of
height and weight in 65 million participants in 200 countries and territories. In 2019, we
estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents
between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and
Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland
for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and …