Trends in growth status among schoolchildren in Sendai, Japan, 1994-2003: Leveling-off of mean body height and weight

Abstract

Secular changes in growth have been well documented in various world populations, with secular increase especially noticeable in the developed countries. Accordingly, we have been monitoring the secular changes in growth status among the 6th year children in primary schools (6thPS, 11-12 years old) and 3rd year children in junior high schools (3rdJHS. 14-15 years old) in the city of Sendai since 1934. After World War II, both primary school children and junior high school students showed marked increases in height and weight up to the early 1970s. Acceleration and the subsequent reduction in the degree of acceleration in growth were observed in 1965-1974 and 1975-1984, respectively, and were followed by reacceleration in 1985-1994. The aim of this study was to assess the growth changes among Sendai schoolchildren in 1994-2003. The period between 1994 and 1999 was characterized by positive trends both in height and weight among schoolchildren. However, the degree of the increases in height and weight was diminished between 1999 and 2003. The linear regression analysis revealed the significant increases in mean weight during the 10-year study period in 6thPS boys and 3rdJHS boys and girls. In contrast, there was no significant increase in mean height in any group. These findings suggest the leveling-off of the mean body height and weight among schoolchildren in Sendai at the end of the 20th century. Additional study is needed to examine possible explanations and consequences of these secular trends. © 2008 Tohoku University Medical Press.