BACKGROUND: Childhood obesity is a major risk factor for adult obesity. Our research aim is to evaluate whether the association of child height and BMI alters the longitudinal tracking from childhood into young adulthood of clinically recommended categories of overweight status.
METHODS: A multicenter prospective cohort study of subjects assessed in both 3rd grade and 12th grade, n = 2,802. Main exposures were CDC childhood body mass index (BMI) categories and height quartiles from 3rd grade measurements. Main outcome measure was CDC adult BMI categories from 12th grade measurements. Associations between childhood height quartiles, childhood BMI categories and adult BMI categories were assessed using chi-square tests and logistic regression models.
RESULTS: Overall, 79% of overweight children remained overweight as young adults. Among children who were overweight or obese, the probability of becoming an overweight or obese young adult was 85% for children in the top quartile of height and 67% for children in the bottom quartile of height (p = 0.007). Among children who were normal weight, the probability of becoming an overweight or obese young adult was 25% for children in the top height quartile v. 17% for children in the bottom height quartile (p = 0.003).
CONCLUSIONS: When clinicians classify children by BMI categories and counsel about the risk for future obesity, they should recognize that greater height is not protective. Rather, greater height may be a marker for increased risk of adult overweight and obesity.