Why is Protein so Important after Surgery? By Edmund B. Chen on May 09, 2024

After bariatric surgery, the body goes through a period of drastic change.  The metabolism is corrected and our patients begin to lose weight.  The number of calories consumed also drastically is reduced after surgery.  With all of these changes, the body begins to break down fat, and the patient begins to lose weight.  However, the goal is to only lose fat and notably, not to lose muscle or lean body mass during this period of rapid weight loss.  During the weight loss period, the body will start to break down muscle in addition to fat if there is not enough protein. The body will break down muscle to release the stored protein to allow the body to perform its necessary tasks.  Lean muscle mass loss can be problematic, as losing muscle makes patients feel weaker and also decreases a patient’s overall metabolic rate.  Therefore, to prevent this, we give the body plenty of extra protein so the body does not need to look to the muscle for the protein it needs.

Before bariatric surgery, the normal daily protein goal is 0.8 g of protein per ideal body weight per kilogram.  For an average-height person, the ideal body weight is about 70 kg.  Therefore, before bariatric surgery, the protein goal was 70 g multiplied by 0.8 g, or about 50 grams of protein/day.  However, studies have shown that if we keep to this lower protein goal after surgery, patients can lose anywhere from 18 to 30% of their muscle mass.

Therefore, after bariatric surgery, we need to increase this protein goal to give the body all the protein it needs without having to break down muscle.  After a sleeve gastrectomy or a RYGB, this protein goal increases to at least 1 -1.2 g of protein per kg.  For an ideal body weight of 70 g, this means that the daily protein goal is now 70 – 80 g / protein per day.  For patients with a SADI-S or duodenal switch, these are more powerful metabolic operations.  Due to the increased weight loss and the changes in small bowel anatomy, the body loses more protein with a SADI-S or Duodenal switch.  Therefore, if a patient had one of these operations, the protein goal is even higher. For a patient with a SADI-S or Duodenal switch, the goal protein goal increases to at least 1.5-  1.8g of protein/day, or about 100 -120 g of protein for an ideal body weight of 70 g. 

importance of protein after bariatric surgeryIt is important to point out that these are long-term goals for protein intake.  In the immediate post-operative period, it will be difficult to immediately reach these high numbers and patients do not need to feel stressed out about not immediately getting in 100 g of protein a day.  Gradually work towards these goals during the healing process of surgery and the majority of patients will reach their goals after a couple of weeks.

Patients often ask me if there is a limit to their protein.  I always say that unless they have chronic kidney issues, more protein is always better.  A sleeve patient who hits 100g or more of protein a day is doing great.  The body will utilize all the protein it can, and the excess will be naturally eliminated.  The more protein you give your body, the more your post-bariatric surgery body will maintain its muscle mass.  With exercise, you can even increase your muscle mass.  The more muscle you have, the faster your metabolism will be and the stronger you will feel!

Protein is important after bariatric surgery! 


Related to This

dr joe cribbins and dr edmund chen DAVINCI robotic bariatric surgeons voted best doctors of Dallas, TX

Texas Center for
Bariatrics & Advanced Surgery

Our highly skilled and experienced board-certified surgeons specialize in ultra-minimally invasive general and bariatric surgery. They are affiliated with a number of national associations, including the:

  • American Board of Surgery
  • American Society for Metabolic and Bariatric Surgery (ASMBS)
  • American College of Surgeons (ACS)
  • Fellow American Society for Metabolic and Bariatric Surgery (FASMBS)

To request a consultation, contact us online or call (214) 501-1333 today.

Contact Us Today

This contact form is for appointments only.
For more information or medical concerns, you can reach our office at (214) 501-1333.
If this is a medical emergency, please call 911.

Rate, Review & Explore

Social Accounts Sprite