[Birth weight and overweight in childhood: a systematic review].

Birth weight is associated with overweight and obesity in childhood. However, results are controversial. The aim of this systematic review is to identify concordant and contradictory aspects on the association between birth weight and overweight in children up to seven years of age. The first eight articles were selected in a previous review evaluating risk factors for childhood obesity. The search in PubMed between 1993 and 2004, using keywords "birth weight AND childhood", "obesity" and "overweight", together with the previous ones added up to 20 papers conforming the review criteria. Despite the studies' heterogeneity, a positive association between birth weight and some kind of childhood obesity was predominant among the published papers. Meanwhile, the inconsistency of some aspects related to birth weight and childhood obesity suggests the need for an approach allowing the inclusion of some context effects on the childhood obesity risk factors framework.