Meat as a first complementary food for breastfed infants: Feasibility and impact on zinc intake and status

Objective: This study was undertaken to assess the feasibility and effects of consuming either meat or iron-fortified infant cereal as the first complementary food. Methods: Eighty-eight exclusively breastfed infants were enrolled at 4 months of age and randomized to receive either pureed beef or iron-fortified infant cereal as the first complementary food, starting after 5 months and continuing until 7 months. Dietary, anthropometric, and developmental data were obtained longitudinally until 12 months, and biomarkers of zinc and iron status were measured at 9 months. Results: Mean (±SE) daily zinc intake from complementary foods at 7 months for infants in the meat group was 1.9 ± 0.2 mg, whereas that of the cereal group was 0.6 ± 0.1 mg, which is approximately 25% of the estimated average requirement. Tolerance and acceptance were comparable for the two intervention foods. Increase in head circumference from 7 to 12 months was greater for the meat group, and zinc and protein intakes were predictors of head growth. Biochemical status did not differ by feeding group, but approximately 20% of the infants had low (<60 μg/dL) plasma zinc concentrations, and 30% to 40% had low plasma ferritin concentrations (<12 μg/L). Motor and mental subscales did not differ between groups, but there was a trend for a higher behavior index at 12 months in the meat group. Conclusions: Introduction of meat as an early complementary food for exclusively breastfed infants is feasible and was associated with improved zinc intake and potential benefits. The high percentage of infants with biochemical evidence of marginal zinc and iron status suggests that additional investigations of optimal complementary feeding practices for breastfed infants in the United States are warranted.