[Spanish growth studies: the current situation, their effectiveness and recommendations for their use].

The child growth assessment is useful not only for the follow up of children's health but also for social purposes, as an indicator of the equity advances in the world. In Spain there has been a long tradition in carrying out growth studies. During the last decade five Spanish research groups have conducted studies among the population of Andalucía, Barcelona, Bilbao, Madrid and Zaragoza. They have combined their data and have produced the "Transversal Spanish Studies 2008 and 2010" and the "Longitudinal Spanish Study 1978/2000". These studies have showed that in Spain the regional differences on growth have disappeared, and that this has had a secular trend in the last decades. The Spanish adult height has approached to other European and American countries, still below some Centre and North European countries. There are some differences between the Spanish growth studies and the multicentric World Health Organization (WHO) growth study. This is due, among other reasons, to the different criteria that are used for the sample selection. In Spain the studies are based on the "population" criteria, whereas the WHO study is based on the "socioeconomic" and "nutritional" criteria. Currently for the Spanish population is appropriate to use, as standard reference, the Spanish multicentric studies, which are the transversal as well as the longitudinal studies. Due to the recent secular trend, it would be convenient to carry out, in the future, prospective transversal growth studies, methodologically homogeneous, representatives of the different Spanish regions, and preferably made every ten to fifteen years.