Objective: The beginning of the post-infancy rise in the body mass index (BMI, kg/m2) has been termed the adiposity rebound, and several studies have found that an early rebound increases the risk for overweight in adulthood. We examined whether this relation is independent of childhood BMI levels.
Design: A longitudinal study of 105 subjects who examined at ages 5, 6, 7, 8 and 19-23 y.
Results: Subjects with an age at the BMI rebound (age(min)) of < or =5 y were, on average, 4-5 kg/m2 heavier in early adulthood than were subjects whose age(min) was > or =7 y. Age(min), however, was also correlated with childhood BMI levels (r approximately -0.5), and we found that age(min) provided no additional information on adult overweight if the BMI level at age 7 y (or 8 y) was known. In contrast, childhood height, which was also correlated with age(min) (r=-0.47), was independently related to adult BMI. Among relatively heavy (BMI=16.0 kg/m2) 5-y-olds, a child with a height of 120 cm was estimated to be 1.2 kg/m2 heavier in adulthood than would a 104 cm tall child.
Conclusions: Although an early BMI rebound was related to higher levels of relative weight in adulthood, this association was not independent of childhood BMI levels. The relation of childhood height to adult BMI needs to confirmed in other cohorts, but it is possible that childhood height may help identify children who are likely to become overweight adults.