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Fasting guidelines for adults

Patient Education
Last reviewed

What can I eat and drink the night before and day of my procedure?

Hours Before Procedure Not Allowed Allowed
8 hours before
  • Do not eat food, unless told differently by your doctor. 
  • Stop food or formula given through a feeding tube. 
  • Keep drinking all fluids.
6 hours before
  • Do not drink non-clear fluids. 
  • Do not eat food. 
  • Keep drinking clear fluids. 
2 hours before
  • Do not eat or drink anything.
  • If you must take prescribed medicines, take them with 1 sip (about 1 ounce) of water. 

Fluid Examples

Non-clear fluids: 

  • Milk
  • Hot chocolate
  • Coffee or tea with milk, cream, or nondairy creamer
  • Orange juice (with or without pulp) and other fruit juices with pulp
  • Smoothies
  • Tube feeds, such as Promote®, Impact®, and Nepro®

Clear Fluids:

  • Apple or white grape juice (not orange juice)
  • Black coffee without milk and cream
  • Clear tea without milk and cream
  • Carbonated drinks, such as Coke® or 7-Up®
  • Clear, fat-free broth 
  • Infant electrolyte drinks, such as Pedialyte®
  • Non-turbid clear protein drinks, such as Ensure Clear®, Premier Protein®, and Fizzique®
  • Sports drinks such as Gatorade®
  • Water

Remember:

  • Clear fluids cannot be hazy or cloudy. They cannot have pulp or fats. 
  • No milk, creamer, or lemon added to any drinks. 
  • No alcohol.
  • Do not swallow gum, mints, or candy.

Why can’t I eat or drink before my procedure?

Our protective reflexes slow down when we are given anesthesia. One protective reflex is to keep stomach contents from going into our lungs. Aspiration can happen when stomach contents enter our airway. This is less likely to happen when your stomach is empty. Fasting (not eating or drinking) keeps your stomach empty.

Why is aspiration bad?

Solid or semi-solid stomach contents that are aspirated into your lungs may block air from getting to your lungs. Liquid stomach contents that are acidic may burn your lungs and stop you from getting air. Both types of aspiration may cause brain damage or death. 

Aspiration can be treated. Most people survive, but treatment in an intensive care unit (ICU) is often needed. Aspiration may lengthen your hospital stay by days to weeks.

Can I have gum or hard candy while waiting for my procedure?

Adults (18 years and older) can chew gum or suck hard candy. Do not swallow gum or hard candy. This counts as a meal. You will need to wait 8 hours for your procedure.

When should I stop chewing tobacco or putting snuff in my mouth before my procedure?

Stop 6 hours before your procedure.

Why can I use apple jelly to take crushed medicines?

Apple jelly is made from apple juice that is boiled and cooled. This causes it to thicken. Apple juice is an approved clear fluid. 

Plain apple jelly can be used to take crushed pills up to 2 hours before a procedure. Do not use pudding or apple sauce.

Who came up with the fasting guidelines?

They are based on research and expert opinion. The American Society of Anesthesiologists and the European Society of Anesthesiologists each have a task force to make guidelines. Doctors in the Department of Anesthesia at the University of Iowa Health Care adapt these guidelines.

To learn more, go to: uihc.org/educational-resources/frequently-asked-questions-about-fasting-guidelines-adults