Probability of adult overweight and risk change during the BMI rebound period

Abstract

Objective: To develop a probability chart of adult overweight based on childhood body mass index (BMI) values and to evaluate the BMI change during the BMI rebound period during childhood, in different populations, with the use of risk function curves. Research Methods and Procedures: A longitudinal growth study of 3650 full-term healthy Swedish children followed from birth to 18 years of age. Weight and height values of our subjects were obtained. Results: A probability chart for reaching a BMI > 23 kg/m 2 at 18 years of age was constructed for boys and girls. For example, a BMI of 18 kg/m 2 at 4 years of age is associated with 0.70 probability of attaining a BMI > 23 kg/m 2 at 18 years of age in boys; a BMI of 16 kg/m 2 at 4 years of age leads to 0.40 probability of having a BMI > 23 kg/m 2 at 18 years of age in girls. Children with an obvious BMI rebound before 8 years of age have a high risk of being overweight at 18 years of age. There is a clear trend of BMI increase from the 1970s to the 1990s in U.S. children from a parallel dataset, and Hispanic children are at the highest risk of adult overweight. Discussion: The probability chart for adult overweight developed here provides a functional method of defining childhood obesity that is based on the risk of long-term ill health rather than on a certain statistical cut-off point. It will help pediatricians or healthcare workers identify those children who are at a high risk of becoming overweight in adulthood, which will allow clinical intervention at younger ages.