Associations of early nutrition with growth and body composition in very preterm infants: a prospective cohort study

Background/Objective To investigate impacts of early postnatal macronutrient intakes on growth and body composition of preterm infants within the first 6 months. Subjects/Methods One hundred and thirty-three very preterm (VPT) and/or very low birth weight (VLBW) infants were consecutively included. Enteral and parenteral macronutrient intakes during the first 28 days were recorded and average daily intakes were calculated. Growth was measured at birth, term age, and 6 months of corrected age (CA). Body composition was examined by air displacement plethysmograph at term age and 6 months of CA. Associations of nutrient intakes with growth and body composition over time were analyzed using generalized estimating equation. Results After adjusting for covariates, higher daily protein, lipid, and energy intake during the first 28 days was associated with higher weight at term age for every 1 g/kg/day increment of protein and lipid intake, and every 10 kcal/kg/day increment of energy intake was associated with 0.50 (95% CI 0.04, 0.96), 0.29 (95% CI 0.07, 0.51), and 0.27 (95% CI 0.10, 0.44) higher weight z -score, respectively. Higher protein intake was associated with lower z -score of fat mass (FM, β = −1.88, 95% CI −3.53, −0.23) and percentage of body fat (PBF, β = −2.18, 95% CI −3.98, −0.39) at 6 months of CA, but higher lipid and carbohydrate intake was associated with higher FM and PBF z -scores at 6 months of CA. Conclusions Macronutrient intakes during the first month of life have impacts on growth and body composition before 6 months of age. Higher daily protein intake is associated with a better growth and healthier body composition for VPT/VLBW infants.