The history of the use of children’s growth as a measure of the nutrition and hygiene of a population since the early 19th century is outlined. Secular trends towards greater height and earlier maturity are reported; the increase in adult height in British men born between 1900 and 1946 averaged about 1.25 cm/decade and in those born between 1946 and 1960 0.6 cm/decade, according to the data of Kuh et al. [Int J Epidemiol 1991;20:1001-1009]. Social class differences in height persist in the UK, amounting to almost 2 cm between the well off and the unskilled. The average height of subgroups of most populations serves well as a proxy for their health status and relates to their mortality rate.