Growth in early infancy and adult fat distribution in a cohort prospectively followed from foetal period to adulthood: the 1966 Northern Finland Birth Cohort study results

Background: While some studies suggest that increased postnatal growth rate maypredispose infants to develop obesity in childhood or adolescence, findings amongadults are limited. We examined the prospective relation between postnatal growthand adult adiposity in the 1966 Northern Finland Birth Cohort study (N=4,987).Methods: Weight at birth and 1 year were prospectively recorded. Adiposity indiceswere measured at a clinic during follow-up at age 31 years.Results: Per 1 kg weight gain by 1 year, adult body mass index (BMI) increased by0.5 (95% confidence interval [CI] 0.4, 0.6) kg/m2. Weight gain of 1 kg by 1 year wasalso associated with higher waist (0.3 [95% CI 0.2, 0.4] cm) and hip circumferences(0.6 [95% CI 0.5, 0.7] cm) but lower waist-hip ratio (WHR) by -0.003 (95% CI -0.004,-0.001) after adjusting for adult BMI, sex and birth weight. Those born in the lowestbirth weight tertile who gained least weight at 1 year also had lower waistcircumference, lower hip circumference and higher WHR when compared to those inthe lowest birth weight tertile who gained most weight at 1 year in both men andwomen. Further adjustments for potential confounders across the lifecourse did notalter our findings.Conclusion: Although impaired postnatal growth was related to lower adult BMI, itwas also related to a more adverse fat distribution pattern. Increased postnatal growth,at least during early infancy, may promote a more favourable adiposity phenotypelater in life.