Does parental body mass index status modify the associations among birth weight, early growth and childhood adiposity?

OBJECTIVES: To examine the associations among birth weight, infant growth and childhood adiposity, and to test whether parental weight status modifies these associations. METHODS: The sample was comprised of 423 participants born at term who were an appropriate size for their gestational age from the Quebec Adipose and Lifestyle Investigation in Youth (QUALITY) study, a cohort of 630 children with a parental history of obesity. Infant growth velocity from zero to two years of age was estimated using slopes from simple linear regression for weight and body mass index (BMI) Z-scores. Child anthropometrics and body composition, and parental BMI were measured from eight to 10 years of age. Associations were modelled using multiple linear regressions. RESULTS: Increased birth weight and growth velocity independently predicted increased childhood adiposity. Effects of infant growth velocity on later adiposity were stronger with higher maternal BMI but not with higher paternal BMI. Similar interactions with birth weight were not found. CONCLUSIONS: Early childhood measures of growth and the mother's BMI score should be included in investigations on obesity risk.