Investigation into the role of cephalic stimulation of acid secretion on gastric emptying and appetite following a soup meal using the gastric acid inhibitor omeprazole

We previously showed that oral administration of a liquid soup preload was associated with a slower rate of gastric emptying and suppressed appetite more compared with intragastric administration of the same soup [Appetite 31(1998)377]. The present study was designed to investigate whether these results could be explained by the cephalic stimulation of acid secretion induced by oral administration. Eight healthy male subjects took part in a double-blind placebo controlled study comparing the effects of omeprazole and placebo on gastric emptying, appetite ratings and subsequent food intake following the ingestion of a liquid soup. Subjects were administered with a single oral dose of 80 mg omeprazole or placebo 3 h prior to ingesting the radiolabelled soup preload (400 kcal; 425 ml) over 15 min. Ratings of hunger, desire to eat and fullness were recorded over 135 min and gastric emptying was measured by scintigraphy. Food intake was evaluated from a test meal (yoghurt drink) given 120 min after the end of the soup ingestion. Analysis of data showed that there was no significant difference between omeprazole and placebo in gastric emptying, appetite or subsequent energy intake from the test meal. The results suggest that gastric acid secretion is not responsible for the differences in gastric emptying and appetite observed between intragastrically infused and orally administered soup preloads.