Growth variation, final height and secular trend

Growth and body height have always been interesting topics in the public opinion. Particularly the stupendous increase of some 15 to 19 cm in final adult height during the last 150 years in most European countries (the “secular trend”), the concomitant changes in body and head proportions, the tendency towards early onset of sexual maturation, the changes in the age when final height is being reached, and the very recent trend in body mass index have generated much scientific literature. The marked plasticity of growth in height and weight over time causes problems. Child growth references differ between nations, they tend to run out of date, and raise a number of questions in regard to fitting methodology, effects caused by selective drop-out etc. New findings contradict common beliefs about the primary importance of nutritional and health related factors on secular changes in growth. There appears to be a broad age span from mid-childhood to early adolescence that is characterised by a peculiar insusceptibility. Environmental factors that are known to influence growth during this age span appear to have only little or not impact on final height. Major rearrangements in height occur at an age when puberty has almost been finished and final height has almost been reached implying that factors which drive the secular trend in height are limited to early childhood and late adolescents.