Have Swiss adult males and females stopped growing taller? Evidence from the population-based nutrition survey menuCH, 2014/2015.

Data from the National Nutrition Survey for adults (menuCH) allow for the assessment of recent trends in measured height by year of birth for adult men and women from a population-based sample. The aim of the present study was to test if - similarly to conscripts and schoolchildren - the Swiss adult population stopped growing taller in recent birth cohorts, and if so, when the change occurred. We found that - when self-reported - height was overestimated on average by about 1 cm in both men and women, with an increasing tendency with older age and with shorter height. Average measured height increased by 4.5-5.0 cm for adult men and women between the birth years 1937-1949 and 1990-1995. However, this increase was not linear, and starting with the 1970s birth years, average height plateaued on a level of about 178 cm for men and 166 cm for women. Being born outside of Switzerland or adjustment for potential shrinkage with increasing age did not change this temporal pattern. We also found shorter average height among participants from the Italian part of Switzerland and those with lower educational level. It remains unclear if the phenomenon of stabilisation affects all subgroups of the Swiss population. Future studies should combine a larger number of population-based surveys to enhance the sample size, for example, for people with a migration background or with different educational levels. Continuing growth monitoring needs to be performed to assess if environmental and demographic changes with an impact on body growth (adverse trends in nutrition, increasing social inequality in health, ethnic composition of the population) positively or negatively influence future trends in average height.