Birth weight, adult body composition, and subcutaneous fat distribution

OBJECTIVES: To investigate if birth weight is related to both body mass index (BMI) and distribution of subcutaneous fat at adult age.

RESEARCH METHODS AND PROCEDURES: A 9-year longitudinal study was performed in 229 subjects (192 women) with ages ranging from 27 to 36 years. Birth weight was retrieved by a questionnaire, and adult weight, height, skinfold thicknesses, and waist-to-hip ratio (WHR) were repeatedly measured at mean ages 27, 29, 31, and 36 years. BMI, sum of four skinfolds (S4S), the ratio between two truncal skinfolds and S4S (SS/S4S), and the ratio between WHR and the cross-sectional area of the left thigh were calculated with the available data.

RESULTS: The adjusted model showed that in women, birth weight was significantly negatively related to adult S4S [beta = -5.211; (-9.768 to -0.654)], waist circumference [beta = -1.449; (-2.829 to -0.069)], and SS/S4S ratio [beta = -3.579; (-5.296 to -1.862)]. In men, a significant negative association was observed between birth weight and adult WHR [beta = -1.096; (-2.092 to -0.100)] only. Other relationships showed, although not significantly, the same negative trend, namely that lower birth weight is related to higher adult body fat mass (S4S) and a more truncal subcutaneous fat distribution (SS/S4S). No associations were found between birth weight and either adult BMI or the cross-sectional area of the thigh.

DISCUSSION: Lower birth weight is, in both adult men and women, related to a higher adult subcutaneous fat mass and a more truncal distribution of subcutaneous fat, indicating a higher risk for obesity.