Objective: To evaluate the feeding tolerance of a high-energy (1 kcal mL(-1)) infant formula (HEIF) for infants with faltering growth, weighing 2.5-8 kg, when administered at full strength from day 1 compared with stepwise introduction.
Methods: Thirty infants (aged 2-43 weeks) from a supraregional children's hospital requiring a high-energy formula for faltering growth were randomly allocated to receive either a 1 kcal mL(-1) ready to feed infant formula at full strength from day 1 or the same formula in diluted form, graded to full strength over 3 days. Bowel actions, vomits and volume of feed taken were recorded daily for 2 weeks. Weight, length, head circumference and mid-upper arm circumference were recorded at recruitment and after 2 weeks.
Results: The number of bowel actions in the first 2 days was significantly higher for the full strength group than for the stepwise group (P = 0.02); younger infants (<12 weeks) had more bowel actions over the first 2 days on the HEIF at full strength (Spearman's correlation = -0.5; P = 0.04); and infants with a total higher energy intake (kJ kg(-1)) had more frequent bowel actions over the first 4 days (Spearman's correlation = 0.48; P = 0.01). There was no significant difference between groups for growth or vomiting.
Conclusions: High-energy infant formula was generally well tolerated in infants under the age of 12 months with faltering growth when administered at full strength from day 1. However, younger infants (<12 weeks of age) may benefit from a graded introduction in order to avoid increased bowel frequency.