Prediction of obesity from infancy to adolescence.

AIM To examine the development of childhood obesity and to determine the earliest age when estimating body mass using only weight and height data is associated with a corresponding estimate at the age of 15. METHODS Subjects included are all children born in 1991 in Östergötland County, Sweden. Weight and height data collected during regular check-ups at well-child centres and school health care assessments up to 15 years of age were assembled from health records. Correlations between childhood estimates of body mass and the body mass index (BMI) at 15 years of age were computed pairwise. Correlations with r > 0.5 were defined as reliably strong. RESULTS Complete data were available for 3579 children (62%). Fewer girls (2.6%; C.I. 1.9-3.3) than boys (4.6%; C.I. 3.7-5.5) were obese at 15 years of age. Correlations with BMI at 15 years of age were strong (significantly higher than 0.5) from 5 years of age. Only 23% of girls and 8% of boys found to be obese at 5 years of age were of normal weight at the age of 15. CONCLUSION From 5 years of age, point estimates of body mass using only weight and height data are strongly associated with BMI at the age of 15. More data sources are needed to predict weight trajectories in younger children.