New growth standards for the 21st century: a prescriptive approach.

Breast-fed babies have been shown to grow at a substantially different rate from the current international reference curves, with greater growth rates in height but with smaller body weight increases and substantially less variability in the growth patterns of a group. On this basis, the World Health Organization concluded that there was a need to undertake new studies to establish on a global basis the appropriate growth curves for exclusively breast-fed babies, their growth curves then being potentially seen as optimum standard curves rather than an arbitrary set of reference charts. The Multi-Country Growth Reference Study was therefore carried out from July 1997 to December 2003 as a population-based study covering the cities of Davis, California, USA; Muscat, Oman; Oslo, Norway; and Pelotas, Brazil, together with selected affluent neighborhoods of Accra, Ghana and South Delhi, India. These centers were considered conducive to a study of babies and children under optimum breast-feeding and weaning and early feeding conditions. These studies, to be reported shortly, confirm previous observations on breast-fed children, but also show that the greatest differences are within each population group rather than being international differences.