Gastric Sleeve Calculator Question

Question Below Submitted By:  

Patricia (a patient from Raleigh, North Carolina)

Hi Doctor,

I’m very ambitious to lose weight by bariatric surgery after using an online gastric sleeve calculator to see how much I’d lose. The gastric sleeve weight loss calculator told me I could lose 60% or more of my bad weight after surgery, so let’s just say I like that. I am average height female, 300 pounds since I was 25.

I watched a documentary on obesity and I’m way fed-up (literally and figuratively). I’m super ready to lose weight and get a gastric sleeve done on my stomach. I know that the liquid and/or semi-solid food diets before and after gastric sleeve help you lose weight.

I’m considering doing the post gastric sleeve diet (liquid diet) for a few additional months after I get surgery. Is it ok to do this? Or is it extreme to stick with the liquid diet for too long? I’d be sure to drink gatorade and other drinks with nutrients.

Patricia Stewart

Bariatric Surgery Source

Expert Responses to the Question Above

Surgeon Response To: Gastric Sleeve Calculator Question

by: John Rabkin, M.D.


The Gastric Sleeve (SG) is a very effective tool to assist you with your desired weight loss. Many Weight Loss Surgery (WLS) programs mandate that prospective patients lose a certain amount of weight either as a fixed number of pounds or as a percentage of their body mass before proceeding with the SG. A liquid diet (medical weight loss regimen) can be very helpful for WLS patients to accomplish that requirement.

After the SG, your gastric (stomach) capacity will be very limited: initially two to three ounces. When you have a severely restricted capacity early after the SG, it may be very difficult to maintain your hydration (your first priority after the SG) as well as consume in a solid form the requisite sixty to eighty grams of protein per day to ensure healing/recovery from surgery and preservation of lean body mass (muscle mass.)

During this initial period of your post WLS recovery, liquid protein supplements can help you achieve your protein intake goals. Furthermore, many morbidly obese patients have success with medical weight loss regimens based on liquid replacement diets; some may have similar beneficial outcomes with these same regimens after undergoing WLS.

My personal philosophy, however, is that once you are able to meet your daily protein consumption goals entirely by eating regular solid food, that you are better off NOT consuming liquid calories of any sort, including liquid protein supplements. My reasoning is that you're more likely to feel satiated (satisfied) for a longer period of time when you consume your calories (including protein calories) in a solid form as it tends to empty more slowly from your gastric pouch when compared with consumption of liquids, thereby prolonging your sense of feeling full and not wanting to eat more/again.

Consequently, I believe that after undergoing the SG, long term you'll be MORE likely to consume FEWER calories over time and enjoy enhanced durable weight loss if you stick with solid food as opposed to liquid diets/supplements following your weight loss surgery.

John M. Rabkin, M.D.
Pacific Laparoscopy

(click here for Dr. Rabkin's full bio & contact info)

DISCLAIMER: This educational advice is based on the depth of your question and the details provided. The above should never replace the advice of your local physicians as they have the ability to evaluate you in person.

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[ Last editorial review/modification of this page : 05/21/2021 ]

* Disclaimers: Content: The information contained in this website is provided for general information purposes and your specific results may vary depending on a variety of circumstances. It is not intended as nor should be relied upon as medical advice. Rather, it is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her existing physician(s). Before you use any of the information provided in the site, you should seek the advice of a qualified medical, dietary, fitness or other appropriate professional. Advertising: Bariatric Surgery Source, LLC has entered into referral and advertising arrangements with certain medical practices, original equipment manufacturers, and financial companies under which we receive compensation (in the form of flat fees per qualifying action) when you click on links to our partners and/or submit information. This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Read More

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