Effect of diet on gastric secretion.

Meals stimulate gastric acid secretion in man and animals. The lowest pH of gastric content in man, however, occurs during the early morning hours. Protein meals are both effective buffers raising the gastric pH immediately after ingestion and potent stimulants to acid secretion lowering the pH as the meal is emptied. Two methods, intragastric titration and marker dilution methods are available for measuring acid output in man to a meal. Acid secretion is influenced by the appetizing qualities and the chemical and physical characteristics of the meal. In man and cat acid secretion in response to a meal can equal the maximal response to histamine and pentagastrin. In the dog, it exceeds it. Fat delays the acid secretory response. Both the vagus nerves and gastrin are implicated in mediating the response.