Growth, overweight and menarche

According to Kramer c.s. of the large PROBIT study (Belaraus) children who are breastfed show slower growth than those who are not (however it would be more correct to phrase this as ‘’children who are not breastfed will grow faster than breastfed children or even grow too fast). The fact that parents, too, will compare the growth of their breastfed infants with the growth of their formula fed counterparts, may according to the researchers lead to the phenomenon of starting earlier than planned with formula supplements or weaning to formula altogether. ‘’More is better’’ seems to be a well-established adagio in both health care providers and parents, but in the case of body weight this may very well be untrue. Several studies have linked a higher body weight in young girls to early onset of puberty. Early puberty exposes girls to an increased risks of prolonged exposure to estrogens. Duration of breastfeeding and of exclusive breastfeeding, too, are linked to the age at menarche. It is possible that more than breastfeeding per se, the role of breastfeeding in weight gain as infant and the effect of not breastfeeding on obesity in pre-puberal children is the central factor in this theme.
Kramer MS, Moodie EEM, Dahhou M, Platt RW: Breastfeeding and Infant Size: Evidence of Reverse Causality Am. J. Epidemiol. (2011) first published online March 23, 2011
Al-Sahab B, Adair L, Hamadeh MJ, Ardern CI, Tamim H: Impact of Breastfeeding Duration on Age at Menarche Am. J. Epidemiol. (2011) kwq496 first published online March 23, 2011 
Terry MB, Ferris JS, Tehranifar P, Wei Y, Flom JD: Birth Weight, Postnatal Growth, and Age at Menarche Am. J. Epidemiol. (2009) 170(1): 72-79 first published online May 13, 2009