Relevance of age-related growth references: Variations in body measurements among girls in relation to their menarche status Short title: Body measurements among adolescent girls

Aim: The objective of this study is to fill the information gap by providing detailed information on the development of girls’ BMI and hip and waist circumferences in correlation with their menarche status and to examine the impact of considering menarcheal age in addition to numerical age in the assessment of overweight and abdominal overweight. Subjects and Methods: The description of data is based on two recently conducted cross-sectional surveys: the German Health Interview and Examination Survey for Children and Adolescents (KiGGS, n=1,942) and the Berlin School Children’s Cohort (BSCOC, n=1,606). Anthropometric data are presented stratified by age in years (11-14) and menarche status. The frequency distribution of overweight and abdominal overweight was calculated according to German reference data. Group comparisons were performed with non-parametric tests. Results: Changes regarding body composition occur mainly during pre-menarche and menarche. In girls in whom menarche had occurred more than 6 months ago, waist circumference and, to a lesser extent, BMI attained stable values, while the values for hip circumference were higher in post-menarche girls. The frequency distribution of overweight and abdominal overweight among post-menarche girls shows that they are more than twice as likely to be overweight and/or abdominally overweight as pre-menarche girls within the same age group. Conclusion: The frequency distribution of overweight and abdominal overweight among girls in a similar age group but with a different menarche status demonstrates that misclassification of girls can arise when only age is taken into account. The progress of maturation is an important factor in assessing the growth and health of adolescents.