The World Health Organization (WHO) released new child growth standards on April 27, 2006. These new growth charts are for children from birth to age five years and are the result of a lengthy and intensive study of child growth that began in 1997. In this study, over 8,000 children from six different countries, including the United States, were closely monitored and measured. The most interesting aspect of this study is that the children all had what is considered an optimal environment for proper growth and development, including breast feeding and mothers who did not smoke.
The growth charts that have been used since the late 1970s here in the United States and around the world have some known drawbacks, including the fact that the data are based on a small sample of children of European ancestry from a single community in the United States who were mostly formula fed. (These charts were revised in 2001 to reflect a wider range of children, including about 1/3 breastfed.) I have noted in my own practice (as have others) that breast-fed babies often do not grow according to the standard growth charts. This new study recognizes that breast feeding is optimal for child growth and nutrition, and it also takes into account children from a variety of ethnic backgrounds and countries. Interestingly, the data on children around the world are remarkably similar; given the same optimal nutrition, children basically grow and develop according to the same pattern no matter what part of the world they are from. Proper nutrition and feeding practices and a healthy environment matter more to childrens proper growth and development than do genetics or ethnicity.
The new standards will be very helpful in comparing every child to the optimal pattern of growth and development. I am most interested in having accurate growth charts for breastfed babies. How do the new growth charts compare to the old ones? Breast-fed babies grow at a faster rate during the first six months of life than what is shown on the old growth charts. The old charts therefore underestimate the number of infants that are underfed or undernourished. After the first six months, however, breast-fed babies slow their rate of growth considerably, a fact which I have noticed clinically and which is now represented on the more accurate growth charts. On the old charts, many breastfed babies from 6-12 months of age look like they are failing to gain weight properly.
The study also assessed growth up to age five years of children with a healthy diet and environment. Compared to our current growth charts, these children basically were not as heavy, which means that we may be currently underestimating the rate of obesity and overweight in young children. This is frightening because according to current standards a large number of young children are already recognized as being overweight. This problem may be even more serious and prevalent than we think.
It will take some time for this new information to work its way into clinical practice.