You should not eat before surgery because food or liquid in your stomach can come back up during anesthesia and get into your throat or lungs. That can cause choking, lung damage, or other serious breathing problems. Anesthesia also lowers the body’s normal airway reflexes, so it is harder to protect the lungs if stomach contents come up.

Typical fasting times are 6 hours for solid food, 2 hours for clear liquids, and 4 hours for breast milk. Clear liquids include water, black coffee, black tea, and juice without pulp. Some hospitals may allow small sips of clear liquid closer to surgery in special cases, but the usual plan is to stop clear liquids 2 hours before.

The goal is to lower the chance of aspiration, which means stomach contents going into the lungs. Verify the exact plan with your surgical or anesthesia team in case they want something different for you.