Pre Op Liquid Diet 2

6 Benefits to the Pre-Op Liquid Diet

June 15, 2016

Most patients are naturally stressed out prior to a major operation such as weight loss surgery. By nature, we are EATING animals first, then DRINKING animals second. Even if it were possible to drink all of our nutrition through a straw, the idea of doing this for life is totally unacceptable to most of us (including me!)  Many of my patients have shared with me they are "stress eaters" and so the idea of not eating when you're anxious prior to your surgery makes it even harder to bear.

With all of this said, I emphatically recommend a liquid diet prior to surgery!

6 Benefits to the Pre-Op Liquid Diet

  1. Liver shrinkage - Ultrasound-based studies have proven that some liver shrinkage does indeed occur.  I've been doing bariatrics for about 16 years and when I started my bariatric career, I didn't put people on liquid diets. I would  have a patient with a liver so large, about 1 in 20, that could not have surgery until they lost weight. In the past 10 plus years since recommending a liquid diet, I can't recall a patient with a liver so large that we have had to delay the procedure. Today, such postponements are rare.
  2. Blood sugar control - 30% of my patients are diabetic and controlling your caloric intake through a liquid diet will improve blood sugar control. This will help decrease the chances of infection.
  3. Hiatal hernia - Patients with heartburn or GERD (gastro esophageal reflux disease) are often times found to have a hiatal hernia. Enlarged livers get in the way of the repair. Your surgeon will do a better job for you because the liver has decreased enough to be out of the way.
  4. Liver retractor - When livers are smaller, I don't put in a liver retractor to perform most weight loss surgeries. This will eliminate the hole that is made under your breastbone which means less pain for you.
  5. Reduction of visceral fat - Losing weight prior to surgery helps decrease complications and give you a better post-surgical experience. Losing weight is helpful with the reduction of visceral fat (abdominal cavity fat) so the surgeon has a better view. With less visceral fat, the potential for less bleeding is increased. You will be able to breathe easier and feel much better. You’ll be able to get out of bed easier so you can move which will decrease your chances of blood clots.
  6. Safer and reduce risks of complications - Stomach motility disorders (gastro paresis) is more frequent than we originally thought. Eating within two days prior to surgery can be hazardous to your health if your stomach empties slower than normal. Food particles can prevent accurate, safe stapling and can create leaks.

Patients who are quite large may be on an extended pre-op diet. I find that it is difficult to ask someone to be on a liquid diet more than three weeks. When this is the case, we will place patients on 75% liquids and 25% solids for a longer period of time.  For the final week pre-op, they will be on a full liquid diet.

Common Questions Asked by Patients

Question: Patients regularly ask me if they are on a liquid diet, generally for two weeks before surgery, and the surgeon recommends a liquid diet three weeks after surgery to prevent staple line leaks, how can they stay on liquids for a total of five weeks?

Answer:  The truth is that the pre-op liquid diet period is the most difficult. Your anxieties will be reduced after the procedure. If the patient is having a Gastric Sleeve (VSG) or a Gastric Bypass (RNY), there is a reduction of the hunger hormone, Ghrelin. The reduction of Ghrelin is a major advantage to curb hunger.

Question:  Another common question, what should a patient do if they cheat during their pre-op liquid diet?

Answer:  I think there are cheaters, and then there are CHEATERS. If you broke down and cheated for a meal, my guess is that you are not alone. But if you cheat for more than one day, it's best to talk to your surgeon. Your surgeon is a part of your team and wants only what's best for you. I encourage the patient to ask their surgeon for advice to see if a compromise or suitable alternative can be reached. I have not found most surgeons to be punitive when a patient confesses.  I think the surgeon will probably have compassionate supportive words to say, and if the surgeon believes it is necessary, will come up with another meal plan.

My words of advice are ... Relax and try to embrace your journey.

Your WLS journey is just about to begin and you will have a full, rewarding new life to move on to. The liquid diet will be a fleeting inconvenient moment you will chuckle about, upon self-reflection, as the start to your new and glorious life!

David Kim


Dr. David Kim has been designated as a "Bariatric Surgeon of Excellence," and is certified by the American Board of Surgery. He is a member of the American Society of Metabolic and Bariatric Surgery and a Fellow of the American College of Surgeons. Dr. Kim works at the Kim Bariatric Institute located in Colleyville, TX.