In 1994 the World Health Organization (WHO) began planning for new growth standards. The main motivation came from the observation that clinically significant differences exist between the growth patterns of healthy breastfed infants and the NCHS/WHO international growth references. The WHO recognised that growth references are often used as standards, that is, as tools that enable assessment of how children ought to grow rather than describing how they grew at a particular time and place. A global standard emphasises the notion that all humans are equal. The key assumption underlying the work is that growth is driven by the environment, more particularly, “the biological reality that environmental differences rather than genetic endowments are the principal determinants of disparities in physical growth”.1

The Multicentre Growth Reference Study (MGRS; 1997–2003) collected data on the growth of 8500 children aged 0–5 years from six sites with various ethnic backgrounds and cultural settings (Brazil, Ghana, India, Norway, Oman and the USA). Only children from privileged, healthy populations were included to reduce the impact of environmental variation. Moreover, their care had to follow recommended practices and behaviours associated with healthy outcomes. The MGRS resulted in the new WHO Child Growth Standards (WHO-CGS), available for height-for-age, weight-for-age, weight-for-height, BMI-for-age, head circumference-for-age, arm circumference-for-age, subscapular skinfold-for-age, triceps skinfold-for-age, and motor development milestones (see http://www.who.int/childgrowth). Special issues of the Acta Paediatrica, Journal of Nutrition and Food Nutrition Bulletin are dedicated to the WHO-CGS.

The WHO-CGS are a set of universal standards and as the interpretation of a standard deviation score (SDS) is the same everywhere, will foster cross-national comparison. Moreover, the availability of a global standard facilitates the construction and validation of widely applicable referral and intervention policies that are based upon it. The MGRS study was carefully carried out and extensively documented, and the standards …