We will measure levels of LC-PUFAS, pro-inflammatory biomarkers, and regulatory hormones (resistin, ghrelin) in serum (35,0-36,6 weeks gestation and 4,0-7,6 weeks postpartum) and breast milk (4,0-7,6 weeks postpartum) in normal weight (n=20) and overweight and obese (n=20) mothers. Blood serum and plasma and breast milk levels of these measures will be compared from pregnancy to postpartum within and between normal weight and overweight and obese women. Additional maternal procedures including questionnaires, anthropometrics, body composition measurements, energy intake measurement, and physical activity measurement will be investigated at 35,0-36,6 weeks gestation and 4,0-7,6 weeks postpartum. Infant procedures including anthropometrics, body composition measurements, stool collection, and energy intake measurement will be investigated at 0,1-0,6 weeks and 4,0-7,6 weeks postpartum.