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.
*Section of Nutrition, Department of Pediatrics, †Pediatric General Clinical Research Center, ‡Section of Developmental and Behavioral Pediatrics, Department of Pediatric, §Department of Preventive Medicine and Biometrics, University of Colorado School of Medicine, Denver, Colorado
Received May 12, 2005; accepted November 9, 2005.
Address correspondence and reprint requests to Dr. Nancy F. Krebs, Professor of Pediatrics, Department of Pediatrics, UCHSC, 4200 East 9th Avenue, Box C225, Denver, CO 80262 (e-mail: email@example.com).
Supported by a research grant from the National Cattlemen's Beef Association, and from General Clinical Research Centers Program, National Centers for Research Resources, NIH Grant Number M01 RR00069; Colorado Clinical Nutrition Research Unit, NIH Grant Number DK48520; Nutrition Training Grant T32-DK07658, K08-DK-02240.