A randomized, controlled trial of a Nordic, protein-reduced complementary diet in infants : effects on body composition, growth, biomarkers, and dietary intake at 12 and 18 months

Background: High intake of protein and low intake of plant-based foods during complementary feeding can contribute to negative long-term health effects. Objectives: To investigate the effects of a protein-reduced, Nordic complementary diet on body composition, growth, biomarkers, and dietary intake, compared with current Swedish dietary recommendations for infants at 12 and 18 mo. Methods: Healthy, term infants (n = 250) were randomly allocated to either a Nordic group (NG) or a conventional group (CG). From 4 to 6 mo, NG participants received repeated exposures of Nordic taste portions. From 6 to 18 mo, NG was supplied with Nordic homemade baby food recipes, protein-reduced baby food products, and parental support. CG followed the current Swedish dietary recommendations. Measurements of body composition, anthropometry, biomarkers, and dietary intake were collected from baseline and at 12 and 18 mo. Results: Of the 250 infants, 82% (n = 206) completed the study. There were no group differences in body composition or growth. In NG, protein intake, blood urea nitrogen and plasma IGF-1 were lower compared to CG at 12 and 18 mo. Infants in NG consumed 42% to 45% more fruits and vegetables compared to CG at 12 and 18 mo, which was reflected in a higher plasma folate at 12 and 18 mo. There were no between-group differences in EI or iron status. Conclusions: Introduction of a predominantly plant-based, protein-reduced diet as part of complementary feeding is feasible and can increase fruit and vegetable intake. This trial was registered at clinicaltrials.gov as NCT02634749