Association between rapid weight gain in early years and subsequent adiposity indices in Portuguese children aged 3 to 5 years

The present study aimed to evaluate the association of rapid weight gain (RWG) in early years with subsequent measures of adiposity in Portuguese children. We used data from a cross-sectional study of a representative sample of 5359 Portuguese children aged 3 to 5 years in 2009-10. Measures of adiposity indices included age-specific body mass index z-score (BAZ) and skinfold (suprailiac, subscapular and triceps) thickness. RWG was defined as the difference between z-scores of weightfor- age and birthweight > 0.67 Standard Deviation. Quantile regression models were used to estimate the difference in the 50th (median) and 90th (upper end) percentiles of each measure by RWG. Rapid weight gain in early years (62.5% of children) was associated with greater levels of BAZ and skinfold thickness measures, both for the median and 90th percentile. For the median, the difference was 1.08 (95% CI: 1.01-1.16) for BAZ, 1.11 mm (95% CI: 0.98-1.25) for suprailiac, 0.99 mm (95% CI: 0.87-1.11) for subscapular and 1.34 mm (95% CI: 1.11-1.57) for triceps skinfolds thickness after the adjustments. The increases in the 90th percentiles of adiposity measures associated with RWG were greater than those in median levels. RWG in childhood was associated with increased levels of adiposity measures, independent of prenatal and childhood factors.