The average height of 18- and 19-year-old conscripts (N=458,322) in Switzerland from 1992 to 2009, and the secular height trend since 1878.

QUESTION UNDER STUDY We determine the causes of secular changes in the average height of the male Swiss population for the first time by analysing an unbiased, individually measured, highly representative height-data sample of 18- and 19-year-old Swiss conscripts (N = 458,322) at the national level spanning the years 1992 to 2009. Furthermore, we add historical context based on earlier data from the same source. RESULTS In 2009, the average height of regularly 19-year-old Swiss conscripts was 178.2 cm. Percentiles were P5 = 168 cm, P10 = 170 cm, P25 = 174 cm, P50 = 178 cm, P75 = 182 cm, P90 = 187 cm, and P95 = 189 cm. Over the course of the 130 years between 1878-79 and 2009 the average height of 19-year-old conscripts increased by a total of 14.9 cm. The distribution shifted upwards. In 1878-79, 5.48% of conscripts were 175 cm tall or taller, but only 0.89% were 180 cm tall or taller. In 2008-09, 71.13% of the conscripts were 175 cm tall or taller, and 41.69% 180 cm tall or taller. In recent decades, this trend has slowed markedly. CONCLUSIONS While the increase in average height among Swiss conscripts (representative 90% of the male Swiss population) since the 19th century is usually attributed to improvements in living conditions, all of the factors contributing to the recent slowdown have yet to be identified.