Effect of Formula Type and Preparation on International Dysphagia Diet Standardisation Initiative Thickness Level and Milk Flow Rates From Bottle Teats

Purpose The purpose of this study was to evaluate the effect of infant formula type and preparation (i.e., ready-to-feed vs. powder) on International Dysphagia Diet Standardisation Initiative (IDDSI) thickness level and milk flow rates from bottle teats/nipples. Method The ready-to-feed and powder formulations of the following products were tested for IDDSI thickness level, using IDDSI guidelines, and for milk flow rate, using established flow testing methods: Similac Advance, Similac For Spit-Up, Enfamil Infant, and Enfamil A.R. Analysis of variance was used to compare flow rates among formula types/preparations. Results Enfamil A.R. ready-to-feed was classified as IDDSI “slightly thick.” All other formula types/preparations were found to be IDDSI “thin” liquids. The standard infant formulas (Similac Advance and Enfamil Infant) had comparable flow rates to each other, regardless of preparation (ready-to-feed and powder). The gastroesophageal reflux–specific formulas (Similac For Spit-Up and Enfamil A.R.) had slower flow rates than the standard formulas; within this category, there were significant differences in flow rates between ready-to-feed and powder. Enfamil A.R. powder had the slowest flow rate, but was the most variable. Conclusion For infants with difficulty coordinating sucking, swallowing, and breathing, clinicians and parents should consider the impact that changes to infant formula type and preparation may have on the infant's ability to safely feed.