Peer-reviewed article
Weight status is associated with puberty timing in girls in Isfahan province, Iran.
Esmaeili M, Maracy MR, Kelishadi R, Mozafarian N, Hashemipour M ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study of nearly 14,000 girls in Isfahan Province, Iran examined how body weight affects the timing of puberty. Girls who were overweight or obese started puberty and menstruation significantly earlier than girls of normal weight or underweight. The research used physical examinations and self-reported ages to measure different stages of sexual development across weight categories. The findings suggest that higher childhood weight is associated with earlier onset of puberty.
Key points
- Obese girls started breast development at 9.68 years compared to 10.61 years in underweight girls
- Median age at menarche was 11.62 years in obese girls versus 13.15 years in underweight girls
- 61.9% of participants were normal weight, while 15.5% were obese and 9.5% were underweight
- The pattern of earlier puberty with higher BMI was consistent across all measured pubertal stages
- 50.2% of the study population had experienced menarche by the time of the study
Limitations
This is a cross-sectional study, so it cannot determine whether weight status causes earlier puberty or if other factors influence both. The study does not examine potential health consequences of earlier puberty or the mechanisms explaining the association.
Abstract
Background This study aimed to examine how Body Mass Index (BMI) influences the timing of puberty in girls. Methods This cross-sectional study included students from urban and rural areas of Isfahan Province, Iran. Breast development was assessed by visual inspection and palpation and pubic hair development was evaluated using Tanner's Sexual Maturation Scale. Participants reported the month and year of menarche. Median ages for each pubertal stage were estimated using probit modelling, and analyses were performed separately by BMI category (underweight, normal weight, overweight and obese). Results A total of 13 886 girls aged 6-18 years participated. According to WHO cut-offs, 61.9% were normal weight, 9.5% underweight, 13.1% overweight, 15.5% obese and 50.2% had experienced menarche. The onset of breast development (≥B2) occurred earliest in overweight (9.59 years) and obese (9.68 years) girls, followed by normal-weight (9.87 years) and underweight (10.61 years) participants. A similar trend was observed across subsequent Tanner stages and pubic hair development. Median age at menarche was 11.62 years in obese girls, 11.76 years in overweight, 12.04 years in normal-weight and 13.15 years in underweight participants. Overall, girls with higher BMI reached pubertal milestones and menarche earlier than their normal-weight and underweight peers. Conclusions Higher BMI in girls is associated with earlier onset of puberty and menarche. These findings highlight the impact of childhood overweight and obesity on pubertal development and underscore the importance of monitoring growth and weight status to anticipate and manage potential health consequences.