Background/objectives:Overweight and obesity are becoming increasingly prevalent problems worldwide. A number of factors in early life have been found to be associated with body composition of neonates or young children but there is limited follow-up data for adolescents. This study aims to describe associations between early nutrition and body composition in adolescents.Subjects/methods:Birth cohort study of 415 pregnant women and their offspring (mean age 16 years). Body composition including fat mass (FM) and lean body mass (LBM) of adolescents at 16 years of age was measured by dual-energy X-ray absorptiometry. Information on maternal food and nutrients intake during the third trimester of pregnancy and breastfeeding was collected by questionnaires soon after birth.Results:A total of 264 mother-adolescents pairs were studied. Maternal antenatal meat intake was positively associated with FM of adolescents (an increase of 0.9%/portion, P0.01). There were also positive associations between maternal energy intake (per 1000 kJ/day), fat (per 10 g/d) and protein (per 10 g/day) intake and offsprings FM (an increase of 1.3%), but these became borderline after adjustment for confounders. Breastfeeding >25 days was negatively associated with FM in adolescents (a decrease of 14%, P=0.01). These associations were independent of the significant association between maternal energy and macronutrient intakes during pregnancy and adolescent intakes at 16 years of age. No significant association was found between maternal dietary intake and lean mass in adolescents.Conclusions: Breastfeeding may have a biological effect that is beneficial for the prevention of obesity. Conversely, higher maternal meat intake during pregnancy may increase FM in adolescents.