The Secular Growth Changes in Height and Weight of Mongolian Children over the Past 50 Years

A little information regarding the changes in height and weight among children in Mongolia is available. The purpose of this paper is to report the secular growth changes in height and weight among schoolchildren in Ulaanbaatar city, Mongolia. The main purpose of the study was to determine the secular changes in height and weight of Mongolian children aged 8-17 years over the past 50 years. Height and weight were measured with Physician Beam Scale. Data analysis was made on SPSS-17.0 software. Arithmetical mean with standard deviation for each group (M ± SD) and standard error of the mean were calculated. In order to detect some changes in height and weight of children in different years, meta-analysis was performed (Cohen’s d). In 1962-2010, there was an statistically significant increase (p < 0.05) in average height of boys at the age of 8, 9 and 13-17 years old whereas there was a decrease of average height of boys aged 10, 11 and 12 years from 1978 to 1992, and 8-10, 14-17 years from 2010 to 2015. An increase in girls’ average height occurred throughout all age groups except decrease in girls’ height aged 10-12 years and 10, 12, 14-17 years in 1992-2010 and 2010-2015 respectively. There was a statistically significant increase (p < 0.05) in average weight for boys and girls throughout all age groups except decrease in weight of children’s of both sexes aged 12-17 years old in 2010-2015. In seven out of 10 age groups (8, 9, 10, 14, 15, 16, 17 years old) heights of boys were decreased with medium size effects in 2010-2015. The present study has shown that there were both upward and downward changes in height and weight of schoolchildren in Ulaanbaatar city during 1962-2015. Keywords: Secular growth changes; Height; Weight; Effect size