BMI screening and surveillance: an international perspective.

International efforts to screen children have previously focused on the problem of malnutrition in the preschool years. The new World Health Organization-derived but US-based data for "optimum" growth in school-aged children may not be accepted in more than a few countries. Currently, an international perspective suggests that those school-aged children's BMIs that, on a percentile-ranking basis, track to adult BMIs of >or=25 kg/m(2) are likely to be associated with an appreciable increased risk of the comorbidities associated with weight gain. There is limited evidence on the value of individually directed help for children with higher BMIs as a national policy, but national surveillance systems are badly needed to allow a better focus on the development of both public health and individual treatment policies.