The body mass index or BMI (weight/height2) is a somewhat crude estimate of nutritional status. However, due to its simplicity and high correlation with total body fat, it has been the method of choice in both paediatric clinics and research over the years. Since BMI is not an equivalent measure of the percentage of body fat in different ethnic groups and in the two sexes, population-specific BMI reference data is needed. Several BMI reference values have been published for French, American, British and Hong Kong children in recent years. In Sweden, weight-for-age and height-for-age reference values, which were published in 1976, are still used as the current national growth reference values. Updated growth reference values are needed for assessing nutritional status due to the secular trend toward and increasing prevalence of childhood obesity. The aim of this study was to produce BMI reference values for Swedish children of paediatric age. The series came from a large Swedish population-based longitudinal growth study of 3650 full-term babies followed from birth to 18 y of age. The children in this data set were born in the early 1970s. The pattern and level of 50th centile BMI values presented here are quite similar to those of the Swedish cohort study in the 1950s. In comparison with the US BMI reference values, the Swedish values are much lower, especially for the higher centile values.
Conclusion: The new Swedish BMI chart from our study may provide a useful tool for paediatricians to assess body fat, and consequently nutritional status, in Swedish children.