The growth of height in early childhood determines the height of Japanese people

(From the school health survey, 1900-2017)

抄録

Since the Second World War, the height of Japanese 17 year-olds has increased 10cm for boys and 6cm for girls. This is a well-known fact. This marked increase in height is commonly believed to be a “phenomenon occurring during the school-age period”, and following this reasoning, it is suggested to be a result of an acceleration or advancement of growth during this interval, and especially during puberty.

However, we reviewed school health statistics surveys since 1900 to 2017 and discovered that the prevailing explanation is incorrect. Furthermore, we found that the increased size of the Japanese people is brought about before children attend school (in early childhood), and that there is a complimentary/negative correlation (boys r=－0.958, girls r=－0.989) between growth during the school-age period and early childhood.