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 .
Body mass index and timing of pubertal initiation in boys.
OBJECTIVE To examine the association between body mass index ( BMI [ calculated as weight in kilograms divided by height in meters squared ] ) and timing of pubertal onset in a population -based sample of US boys . DESIGN Longitudinal prospect i ve study . SETTING Ten US sites that participated in the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development . PARTICIPANTS Of 705 boys initially enrolled in the study , information about height and weight measures and pubertal stage by age 11.5 years was available for 401 boys . MAIN EXPOSURE The BMI trajectory created from measured heights and weights at ages 2 , 3 , 4.5 , 7 , 9 , 9.5 , 10.5 , and 11.5 years . MAIN OUTCOME MEASURE Onset of puberty at age 11.5 years as measured by Tanner genitalia staging . RESULTS Boys in the highest BMI trajectory ( mean BMI z score at age 11.5 years , 1.84 ) had a greater relative risk of being prepubertal compared with boys in the lowest BMI trajectory ( mean BMI z score at age 11.5 years , -0.76 ) ( adjusted relative risk = 2.63 ; 95 % confidence interval , 1.05 - 6.61 ; P = .04 ) . CONCLUSIONS The relationship between body fat and timing of pubertal onset is not the same in boys as it is in girls . Further studies are needed to better underst and the physiological link between body fat and timing of pubertal onset in both sexes
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 .