Gastric emptying

Gastric emptying is the rate at which the stomach passes its contents into the small intestine. It shapes how quickly you feel full, how long fullness lasts, and how sharply blood glucose rises after a meal.

It matters because slowing it is one of the main ways GLP-1 signalling reduces appetite — and it explains the common side effects of the medicines, including nausea, early fullness and reflux. It has clinical consequences too: delayed emptying is why anaesthetic and endoscopy teams now ask about these medicines before procedures, since the stomach may not be empty when standard fasting rules assume it is.

In practice, anyone taking these medicines should tell any clinician arranging surgery, sedation or an endoscopy, and follow the fasting instructions that team gives.

Sources

• The Efficacy of GLP-1 Analogues on Appetite Parameters, Gastric Emptying, Food Preference and Taste Among Adults with Obesity: Systematic Review of RCTs; PMC9987242
• GLP-1 receptor agonists and delayed gastric emptying: implications for invasive cardiac interventions and surgery; PMC11620716