There is no consistent result in the relationship between obesity and timing of pubertal onset in boys .
Obesity may contribute to early onset of puberty in girls , while in boys , there is insufficient data .
This systematic review and meta- analysis examined the associations between obesity and puberty timing based on scientific evidence .
Early Life Growth Predicts Pubertal Development in South African Adolescents123
Background : Given global trends toward earlier onset of puberty and the adverse psychosocial consequences of early puberty , it is important to underst and the childhood predictors of pubertal timing and tempo . Objective : We examined the association between early growth and the timing and tempo of puberty in adolescents in South Africa . Methods : We analyzed prospect ively collected data from 1060 boys and 1135 girls participating in the Birth-to-Twenty cohort in Soweto , South Africa .  Height-for-age z scores ( HAZs ) and body mass index – for-age z scores ( BMI Zs ) were calculated based on height ( centimeters ) and body mass index ( kilograms per meter squared ) at ages 5 y and 8 y. The development of genitals , breasts , and pubic hair was recorded annually from 9 to 16 y of age with the use of the Tanner sexual maturation scale ( SMS ) . We used latent class growth analysis to identify pubertal trajectory classes and also characterized children as fast or slow developers based on the SMS score at 12 y of age . We used multinomial logistic regression to estimate associations of HAZ and BMI Z at ages 5 and 8 y with pubertal development . Results : We identified 3 classes for pubic hair development ( for both girls and boys ) and 4 classes for breast ( for girls ) and genital ( for boys ) development . In girls , both HAZ and BMI Z at age 5 y were positively associated with pubic hair development [ relative risk ratio ( RRR ) : 1.57 , P < 0.001 and RRR : 1.51 , P < 0.01 , respectively ] , as was BMI at age 8 y ( RRR : 2.06 , P = 0.03 ) ; similar findings were observed for breast development . In boys , HAZ and BMI Z at age 5 y were positively associated with pubic hair development ( RRR : 1.78 , P < 0.001 and RRR : 1.43 , P < 0.01 , respectively ) ; HAZ at age 5 y was associated with development of genitals ( RRR : 2.19 , P < 0.01 ) . Conclusion : In boys and girls , both height and body mass index in early childhood predicted the trajectory of pubertal development . This may provide a tool to identify children at risk of early pubertal onset
There is no consistent result in the relationship between obesity and timing of pubertal onset in boys .
Obesity may contribute to early onset of puberty in girls , while in boys , there is insufficient data .
This systematic review and meta- analysis examined the associations between obesity and puberty timing based on scientific evidence .