Trends in thin body stature among Japanese female adolescents, 2003–2012

Abstract

Background: The past decades have witnessed a steady increase in thin body stature associated with unhealthy dieting among Japanese female adolescents. The most recent trends in thinness, however, have not been reported.Aim: To describe changes in the distribution of body mass index (BMI) of Japanese female adolescents, from 2003–2012.Subjects and methods: This study examined BMI distribution changes in 2541 relatively affluent Japanese girls, aged 12.5–17.5 years, during 2003–2012. The 2003 and 2004 data were combined and compared to the combined 2011 and 2012 data. Tukey mean-difference plots were used to study the direction and magnitude of shifts in BMI distributions.Results: Prevalence of thinness (BMI <5th percentile of the 1978–1981 references) has progressively increased from 2.0–5.7% in 2003–2004 to 3.5–7.8% in 2011–2012 in Japanese girls. The downward shift in BMI was larger in 12.5–14.5 year olds than in 15.5–17.5 year olds and more prominent in the lower BMI spectrum.Conclusion: The trend towards thinness has continued in Japanese girls during the past decade. The distribution of BMI suggests thinner and younger sub-groups of girls are more susceptible to this trend.