“…The data represent periods , i.e., children measured in particular years, not cohorts of children born in the same year. South Korean data were available only for the years 1965, 1975, 1984, 1997, and 2005 (J. Y. Kim et al, 2008), while the Japanese data came from annual National Nutrition Surveys carried out between 1949 and 2011 by the Japanese Ministry of Health and Welfare (latterly Ministry of Health, Labor and Welfare)—see Funatogawa, Funatogawa, Nakao, Karita, and Yano (2009) for details. The South Korean surveys were very large, with each age group mean based on 15,000 to 60,000 children, while the Japanese samples were much smaller, ranging in size from 500 to 3500 for all ages 1–20 years.…”