Which of the following hormone is not involved in regulation of food intake?

Ghrelin is secreted primarily by the stomach especially during fasting, and stimulates appetite. Peptide YY (PYY), Cholecystokinin (CCK), and Insulin are gastrointestinal hormones that are released by the ingestion of food and suppress fuher feeding. Gastrin has no role in regulation of food intake. Leptin is a hormone produced in increasing amounts by fat cells as they increase in size. It inhibits food intake.