Weight Loss Surgery: How to Prepare

Prep work typically starts six months before the day of surgery

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If you and a healthcare provider have decided you need weight loss surgery (also referred to as bariatric surgery) to improve your health, you’ll soon start the journey to prepare for surgery. But surgery won’t happen immediately.

In fact, most insurance companies require a six-month period where you’ll learn the lifestyle habits you’ll need to adopt now and maintain beyond surgery to help ensure a successful outcome. Once you’ve completed this, you’ll get the green light for surgery from your insurance company. Here’s how to prep on the day of your procedure.

preparing for weight loss surgery
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Weight loss surgery is done in a hospital, as you’ll need to have general anesthesia for the procedure itself. Once you arrive at the hospital, you’ll change into a gown in the surgical area and meet with the team that will be with you during the procedure, including the anesthesiologist, nurses, and surgeon.

They’ll take your weight and height before the procedure, calculate your body mass index (BMI) and place an IV in your arm to start sedation. This is all done in a pre-op area, and typically a friend or family member can be with you while you wait to go into surgery.

Once your healthcare team is ready, you’ll be taken back into a surgical room for the weight loss surgery. This takes anywhere between one to three hours depending on the type of procedure you're getting. Once the surgery is over you’ll wake up in a recovery room before being moved to your hospital room where you’ll complete your stay.

The length of your hospital stay depends on what type of weight loss surgery you get. A gastric band procedure doesn’t require an overnight stay in the hospital while a gastric bypass procedure usually requires a two- to three-night stay in the hospital afterward.

What to Wear

Wear comfortable clothing for your trip to the hospital, and make sure you have no jewelry on. What you wear the day of your procedure isn’t too important, since you’ll change into a hospital gown shortly after arriving.

You just want to make sure you have loose-fitting clothing or leggings to wear after the procedure as the healthcare team will want you to move around as soon as you’re able to.

Things that button or zip up the front are often easiest to get on, so opt for sweats or pajamas to help you stay comfortable during your hospital stay. Stay away from restrictive clothing like jeans.

Food and Drink

You will have a strict food and drink schedule prior to weight loss surgery. Depending on your surgeon’s preference and the type of weight loss surgery you may be placed on a liquid protein diet two to three weeks before your procedure, in addition to taking certain multivitamins or supplements to make sure you’re getting all of the nutrients you need.

Two days before the surgery it may be recommended to stick to a clear liquid diet. Things like broth, water, and sugar-free Jell-O, and certain soups are safe bets to help prep your digestive tract. No food or drink will be permitted after midnight on the day of your weight loss surgery.


Avoid taking medications like aspirin, blood thinners, or NSAIDs for at least a week before surgery, as well as the day of surgery.

If your weight loss procedure is gastric bypass or a gastric sleeve a healthcare provider may instruct you to take magnesium citrate two days before the procedure to help empty out the digestive tract. This is a laxative that can be bought over the counter and increases fluid in the small intestine to produce an increase in bowel movements.

Make sure you discuss ahead of time any medications you may be taking for preexisting conditions like diabetes or heart disease with the healthcare provider. They’ll be able to tell you how long it’s safe to take each one prior to your procedure as well as if your dose will need to be altered after surgery, since certain drugs have different absorption rates by the intestines.

What to Bring

While your hospital stay will be relatively short (one to three days max), make sure in addition to comfortable clothing you pack toiletries, slippers, a cell phone charger, a book, and anything else that will help you recover. (Don’t stress out too much about this, your hospital will provide a packing list for helpful reminders of what to bring from home.)

Many candidates for weight loss surgery also have sleep apnea and should bring their CPAP machine if so to help them sleep at night.

Have a friend or family member stock your pantry while you’re in the hospital if you don’t have time to do it yourself beforehand with a list of approved food and drinks you’ll get from your nutritionist as well as some over the counter medicines like TUMS and Tylenol in case you need them post-surgery once you get home to help ease into eating solid foods again.

Pre-Op Lifestyle Changes

The biggest amount of prep before weight loss surgery will take place months before the day of surgery. This will include anywhere between four to six months of consultations with different members of the healthcare team who will help you set goals to start losing weight ahead of the surgery with a strict diet, exercise plan, and smoking cessation plan if needed.

You will learn to use tools to identify and solve any obstacles to healthy eating or challenges you may come across (such as how to navigate a restaurant menu).

This may include journaling, phone check-ins, in-person visits, and ongoing communication to make sure you understand and are able to achieve the milestones you need to in order to have a successful outcome during and after surgery.

A Word From Verywell

Preparing for weight loss surgery is a time-consuming effort, but it’s important to remember that the work you put in prior to the procedure the better your outcome will be, and the faster you will recover.

Thankfully, you’ll have a team of professionals you’re already familiar with such as a nutritionist, mental health specialist, and possibly a fitness trainer who can help answer any questions you have and give you the materials you need to prep along the way.

This in addition to the support system of your friends and family to help you on the day of the procedure will all help make preparing for weight loss surgery a little smoother.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. UPMC. Preparing for Bariatric Surgery.

  2. Northern Westchester Hospital Northwell Health. What To Expect for the Day of Your Surgery.

  3. Ramsay Health Care. Weight loss surgery basics 10 things to know before the procedure.

  4. Penn Medicine Princeton Health. Preparing for bariatric surgery.

  5. University of Florida Health. Liquid diet before bariatric surgery.

  6. University of Minnesota Health. Before Your Weight Loss Surgery.

  7. UPMC PinnacleHealth. How to Prepare for Bariatric Surgery.

  8. Kaiser Permanente. Bariatric surgery program guide.

By Colleen Travers
Colleen Travers writes about health, fitness, travel, parenting, and women’s lifestyle for various publications and brands.