f you have a surgical procedure in your future, you probably have questions about what’s safe to eat and drink before you head to the hospital and when you should start fasting in preparation for surgery. Anesthesiologists used to recommend that patients scheduled for surgery refrain from eating and drinking starting at midnight prior to surgery, but that’s changed. The American Society of Anesthesiologists has now revised the guidelines to be a bit more flexible.

What Do the Revised Guidelines Say?

The new guidelines let patients consume clear liquids — beverages such as tea, black coffee, apple juice, water or Gatorade — up to two hours before a surgical procedure. The new guidelines advise pre-surgical patients not to consume beverages such as milk, as fat moves too slowly through the digestive tract.

The old guidelines were based on studies from the 1950s. The biggest concern at that time was that consuming food or drink too close to surgery could trigger vomiting during the procedure, making it difficult to keep an open airway. For procedures that require general anesthesia, that’s less of a concern as you’ll have a tube inserted into your trachea during the surgery to keep your airway open at all times. In fact, more recent studies suggest that patients undergoing surgery may do better if they consume clear fluids up to two hours before surgery.

Though most anesthesiologists follow the newer, less-stringent guidelines by the American Society of Anesthesiologists, some still adhere to the stricter recommendation of no food or drink after midnight the day before surgery. That’s why it’s important to discuss this issue with your anesthesiologist during your pre-surgical assessment.

Fruits and vegetables are always healthy options, but you should avoid them for at least a day prior to surgery.

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What Foods Should I Avoid Before Surgery?

For the week prior to surgery, it’s important to monitor your diet. Studies show that certain foods impact how the anesthetic agents you will receive during surgery are metabolized or broken down, and they can affect how long the anesthesia stays in your body. Once surgery is over, you want the effects of the anesthesia to diminish quickly so you feel like your old self again and start the process of recovery.

All pre-surgical patients should avoid foods that contain a natural compound called solanaceous glycoalkaloids (SGAs) — which are found in tomatoes, potatoes and eggplant — for at least seven days prior to any surgical procedure. As University of Chicago Medicine reports, even small quantities of these substances slow the breakdown of anesthetic drugs, which then stay in your system longer, delaying recovery from anesthesia and prolonging its effects.

Fruits and vegetables are always healthy options, but you should avoid them for at least a day prior to surgery. Vegetables and fruits are high in fiber and slow to digest, so it’s possible for them to still be in your digestive tract when surgery begins. Within 24 hours of any surgical procedure that involves anesthesia, you should avoid high-fiber foods of all types, including fruits, vegetables, legumes, nuts, and whole grains.

During the two weeks leading up to surgery, you should avoid eating fish or taking fish oil or omega-3 supplements. Omega-3 fats can interfere with blood clotting and increase bleeding during surgery. You should even avoid some spices for the same reason, including two common ones: garlic and ginger.

What Foods Should I Stay Away from After Surgery?

Since constipation can be an issue after surgery, especially if you’re taking pain medications, add more fruits, vegetables, whole grains, and other high-fiber foods back into your diet. These foods are also nutrient dense to help optimize the healing process. Just remember to stop foods with SGAs seven days prior to the procedure and high-fiber foods 24 hours before.

The Bottom Line

Follow your physician’s instructions — whether they go old school or with the new guidelines — when prepping for any surgical procedure. Choosing to go that extra mile by avoiding certain foods leading up surgery and adding certain foods back in after the event will help to minimize discomfort and speed up your recovery.


Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration: Application to Healthy Patients Undergoing Elective Procedures  Retrieved February 12, 2018

 The University of Chicago Medicine. (October 20, 1998) Potatoes Prolong Anesthetic Action Retrieved February 12, 2018, from http://www.uchospitals.edu/news/1998/19981020-spudstudy.html

Pandit, Sujit K. MD; Loberg, Katherine W. BS; Pandit, Uma A. MD. Coffee is Not a Clear Liquid. Anesthesia & Analgesia (91)(5), 1308. Retrieved February 12, 2018, from https://journals.lww.com/anesthesia-analgesia/Fulltext/2000/11000/Coffee_Is_Not_a_Clear_Liquid.54.aspx

Kristie Leong M.S., M.D.

Kristie Leong M.S., M.D.

Kristie Leong M.S., M.D. is a family physician and health writer. She earned a medical degree and master’s degree in clinical pathology from Medical College of Virginia. Dr. Leong has a special interest in the role nutrition plays in health and disease.

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