• Breastfeeding;
  • growth;
  • infant feeding;
  • linear growth;
  • protein intake;
  • weaning

The aim of this study was to examine the nature of the association between breastfeeding, complementary feeding and growth in a random sample of infants from Denmark, where the prevalence of breastfeeding is high. A semiquantitative food frequency questionnaire and a questionnaire on breastfeeding duration and on weight and length measurements taken at the infant welfare visit at 5 and 10 months were sent to 590 families with 10-month-old infants. A total of 339 infants with complete growth data were included in the analyses. When controlling for mid-parental height and birth weight infants breastfed for ≥ 7 months gained 198 g less in weight (p < 0:01) and 7 mm less in length (p < 0:01) during the period from 5 to 10 months than infants breastfed for < 7 months. Controlling for these effects, the 10% of the sample with the highest protein intake (i.e. ≥16 energy percentage) gained 262g more than those with a lower protein intake (p= 0:03). Infants breastfed for ≥ 7 months received significantly less cow's milk (p < 0:01), and fewer meat-containing dishes (p < 0:05) and sweets or cakes (p < 0:01), which may partly explain the effect of breastfeeding. The long-term consequences of this moderate difference in growth velocity are unknown and the findings should not be used to advocate against breastfeeding during late infancy.