ROLE OF CALORIC CONTENT ON GASTRIC-EMPTYING IN HUMANS

1. This study examined the effects of caloric content (caloric density and the nature of calories) on the rate of gastric emptying using the double-sampling gastric aspiration technique. Four test meals of 600 ml (glucose, 0.1 kcal ml(-1); pea and whey peptide hydrolysates, both 0.2 kcal ml(-1); milk protein, 0.7 kcal ml(-1)) were tested in six hea lthy subjects in random order on four separate occasions. 2. The gluco se solution was emptied the fastest with a half-time of 9.4 +/- 1.2 mi n (P < 0.05) and the milk protein the slowest with a half-time of 26.4 +/- 10.0 min (P < 0.05); the pea peptide hydrolysate and whey peptide hydrolysate solutions had half-times of emptying of 16.3 +/- 5.4 and 17.2 +/- 6.1 min, respectively The rates of gastric emptying for the p eptide hydrolysate solutions derived from different protein sources we re not different. 3. Despite the lower rate of gastric emptying for th e milk protein solution, the rate of caloric delivery to the duodenum during the early phase of the gastric emptying process was higher than that for the other three solutions (46.3 +/- 6, 63.5 +/- 22, 62.5 +/- 19 and 113.8 +/- 25 cal min(-1) kg(-1) for the glucose, pea peptide h ydrolysate, whey peptide hydrolysate and milk protein meals, respectiv ely; P < 0.05). The caloric density of the test solutions was linearly related to the half-time of gastric emptying (r = 0.96, P < 0.05) as well as to the rate at which calories were delivered to the duodenum ( r = 0.99, P < 0.001).