What is the ileal brake?

• A. An inhibitor feedback effect produced by fat in the distal ileum that slows gastric emptying and intestinal transit
• B. A hormonal signal from the stomach that increases appetite
• C. A mechanism that accelerates intestinal transit after fat meals
• D. A process that increases gastric acid secretion

Answer: (A)

The ileal brake is a feedback mechanism activated when fat reaches the distal ileum. In response, the ileum releases inhibitory hormones (notably peptide YY and GLP-1) that slow gastric emptying and intestinal transit. This gives the gut more time to absorb nutrients and also contributes to postprandial satiety. The statement described matches this mechanism exactly: fat in the distal ileum triggers a feedback signal that slows gastric emptying and transit. It is not driven by the stomach, does not accelerate transit, and does not increase gastric acid secretion.