Height, weight and menarcheal age of Oslo schoolchildren during the last 60 years.

Every 5th year since 1920 the heights and weights of all Oslo schoolchildren (aged 7 to 18 years) have been measured, and the measurements processed centrally. For ages between 8 and 14 the mean height increased by about 4 cm per decade between 1920 and 1940 for both sexes. A drop of about 1.5 cm occurred during World War II, followed by a rapid catch-up. Since 1950, height has increased only moderately. A weight increase of between 1.5 kg (8 years old) and 3.5 kg (13 years old) per decade before 1940 was followed by a drop during the war equivalent to somewhat less than one decade's gain. A rapid catch-up after the war was followed by a slight decrease since 1950, especially for ages above puberty. A stable difference in the social composition of the eastern and western districts of Oslo allowed comparison of the trends for lower and higher social strata. Before the war, children from higher strata were taller than children from lower strata, but this difference has now practically disappeared. Children from the higher strata weighed more until about 1955, but later those from the lower strata weighed markedly more, especially during adolescence. The difference in menarcheal age between social strata was examined in 1928, 1952, 1970 and 1975. The time trend parallels that for weight: menarcheal age was lowest among higher strata until the 1950s, but after that the lower strata experienced the lowest menarcheal age.