Is more Hydrochloric acid produced in the stomach in the presence of proteins and fats?

HCl is also secreted in response to gastric distention (=when food gets into the stomach and dilates it). It does have a major role in digestion, as it lowers the gastric pH so that the enzymes have the suited environment to get activated. When tactile receptors sense the presence of food in the stomach, several hormones are released into the circulation, influencing the HCl secretion. For example, the G cells release gastrin when amino acids and peptides (products of protein digestion) are present on the luminal surface, which stimulates the acid secretion, whereas fat solutions that reach the duodenum an jejunum inhibit it.