The Effect of Prolonged Glucagon-like Peptide 1 Infusion on Gastric Emptying in Healthy Volunteers

This study is testing whether a gut hormone called GLP-1, which normally slows down stomach emptying, becomes less effective over time if it is given continuously. This is relevant to understanding how GLP-1-based diabetes and weight loss medications work in the body over the long term. Healthy volunteers will receive either a GLP-1 infusion or a saltwater (saline) infusion on two separate occasions, and stomach emptying will be measured using a low-dose nuclear medicine test. You may be eligible if: - You are between 18 and 35 years old - You are in good health with normal stomach function You may NOT be eligible if: - You have diabetes or a blood sugar marker (HbA1c) above 6.0% - You are pregnant - You have had surgery on your small intestine - You take medications that affect stomach movement or blood sugar - You have had excessive radiation exposure in the past 12 months - You smoke more than 10 cigarettes per day - You drink more than 20g of alcohol per day - Your iron stores (ferritin) are below 20 microg/L - Your kidney function is reduced - You have had 3 or more CT scans or 10 or more X-rays in your lifetime (due to radiation exposure concerns) Talk to your doctor about whether this trial might be right for you.