Randomized comparison of a nutrient-dense formula with an energy-supplemented formula for infants with faltering growth

INTRODUCTION: The practice of supplementing standard infant formula with energy for infants with faltering growth has been widespread. This increases energy density but disturbs the protein : energy ratio, and increases risks of microbial contamination and errors in feed preparation. This study aimed to compare the effectiveness of a nutrient-dense formula (NDF) with an energy-supplemented formula (ESF) in infants with faltering growth. METHODS: In an open, parallel, randomized study, 49 infants with faltering growth were randomized to receive a NDF (4.2 kJ mL(-1)) or an ESF (4.2 kJ mL(-1)), for 6 weeks. Anthropometry, biochemistry, feed intake, stool and vomit frequency were collected. RESULTS: No significant differences in tolerance, feed volumes or energy intakes were recorded but the NDF group received 42% more protein and 15-40% more vitamins and minerals. Blood urea concentration in the ESF group fell by 50% over the trial period, suggesting a suboptimal protein : energy ratio in the ESF feed. The NDF group retained a normal mean blood urea concentration, a higher urinary potassium concentration and did not have the significant fall in length z-score seen in the ESF group. CONCLUSION: Increasing the energy content of normal infant formula without also increasing protein and micronutrients should not be practiced in infants with faltering growth.