Percent body fat at age 5 predicts earlier pubertal development among girls at age 9.
OBJECTIVE
This study examines the causal direction of the relationship between weight status and pubertal timing in girls using a longitudinal sample of 183 white girls followed from ages 5 to 9.


METHODS
Girls' weight status (body mass index percentile, percent body fat, waist circumference) was assessed when they were 5, 7, and 9 years old, and their pubertal development was assessed when they were 9 years old (breast development, Estradiol, Pubertal Development Scale). Information from all measures of pubertal development at 9 years was combined to identify girls exhibiting earlier (N = 44) and later (N = 136) pubertal development relative to the sample. Girls' weight status at each age (5, 7, and 9 years old) and change in weight status across the ages of 5 to 9 years were used to predict their pubertal timing at 9 years of age.


RESULTS
Girls with higher percent body fat at 5 years, and girls with higher percent body fat, higher BMI percentile, or larger waist circumference at 7 years, were more likely to be classified with earlier pubertal development at 9 years. In addition, girls showing larger increases in percent body fat from 5 to 9 years of age, and larger increases in waist circumference from 7 to 9 years of age, were more likely to exhibit earlier pubertal development at 9 years. Results were still present after controlling for accelerated growth.


CONCLUSIONS
Girls with higher weight status in early childhood were more likely to exhibit earlier pubertal development relative to peers at 9 years, indicating that weight status preceded pubertal timing in girls.
Davison
Kirsten Krahnstoever
KK
Department of Human Development and Family Studies, Pennsylvania State University, University Park, Pennsylvania 16802, USA. kdavison@psu.edu
Susman
Elizabeth J
EJ
Birch
Leann Lipps
LL
D000273:Adipose Tissue / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D001940:Breast / Q000254:growth & development; D002648:Child; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D004958:Estradiol / Q000097:blood; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D011627:Puberty / Q000502:physiology*; D012727:Sex Characteristics; D044465:White People
D004958:Estradiol