Gastric emptying of meals of human milk or infant formula was studied in 17 healthy infants aged 4 weeks to 6 months using a marker dilution technique. In the 24 studies performed gastric emptying followed a biphasic pattern in 11 and a linear pattern in 12 studies. The average gastric half-emptying time for meals of human milk was 48 min, and for meals of infant formula 78 min. After 1 hour an average of 29.5 ml of human milk and 22.7 ml of infant formula per 0.1 m2 of body surface area had emptied from the stomach.