Is Whey Protein the Best Option for Post Gastric Bypass Surgery?

December 2, 2022
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Meeting your protein intake requirements is integral to the weight loss journey. For patients who’ve undergone bariatric surgery, protein is essential for many reasons—wound healing, muscle repair, healthy weight loss, satiety, and blood sugar—and grabbing a protein drink can be a quick and convenient way to help meet your protein needs. But there’s something we must know about protein powders: protein supplements are not created equal, and not all supplements are suitable for bariatric patients. Is Whey Protein the Best Option for Post Gastric Bypass Surgery?

While some proteins are designed to help you gain mass, New Zealand Grass-Fed Whey Isolate provides a superior alternative to accelerate recovery and support post-surgery weight loss thanks to its clean nutritional profile, high bioavailability, and fantastic taste.

If you’re post-op and looking for a clean protein to supplement your weight loss journey, we’re going through all the details on why DIESEL New Zealand Whey Isolate might be the best option after bariatric surgery.

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What’s the best protein powder after gastric bypass surgery?


When it comes to choosing a protein powder, there are several options—whey, egg white, beef, pea, hemp, and of course, blends. But if there’s one protein scientifically backed as effective for bariatric patients, it’s whey protein isolate. Why? With a high bioavailability and a solid nutritional profile, whey isolate provides all of the essential amino acids for building functional proteins without the typical gastric side effects of other types of protein.

During periods of caloric restriction, such as after gastric bypass surgery, the macronutrient profile of the diet plays a big role in regulating the modifications to body composition post-surgery. While carbohydrates and fats are important, protein, in particular, is critical for regulating lean muscle mass. Studies show that increased protein intake can preserve muscle mass and basal metabolic rate while simultaneously promoting weight loss.1

While protein may be important for retaining muscle mass post-op, what’s the best choice to maximize muscle maintenance?

Most studies suggest that proteins with a higher branched-chain amino acid (BCAA) content are usually preferred, which may suggest animal-based proteins over plant-based, as the ratio of essential amino acids is more complete.1 Whey isolate, for example, is the purest and most concentrated source of whey protein that provides the highest protein concentration (90-95%) with minimal lactose to avoid GI distress and is rich in essential amino acids, including the BCAAs, with the highest concentrations of leucine2; leucine is the most potent stimulator of muscle protein synthesis compared to all other amino acids. It’s also more soluble, easy to digest, and highly bioavailable.

That said, although protein is an essential component of the diet to support immune function, muscle growth, and overall optimal physiological function, it becomes critical after bariatric surgery for weight loss and recovery.

The importance of protein for weight loss


When you’ve just finished a hard training session, you know protein is necessary to stimulate the repair and growth process. But during periods of rapid weight loss, adequate dietary protein intake is also essential to maintain muscle mass, especially when energy intake is restricted. But apart from muscle maintenance, there are several other functions of protein after gastric bypass surgery and weight loss:

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Another primary reason protein is important post-surgery? It’s involved in maintaining the elasticity of the skin, which can help to prevent skin sagging, a common issue among bariatric surgery patients.

Types of whey protein


When choosing a whey protein, you’ll find three options: concentrate, isolate, and hydrolysate.3 What’s the difference?

  1. Whey protein concentrate: A type of whey protein made through ultrafiltration of whey to contain 70-80% protein. It contains higher amounts of lactose and fat and often has the best flavor.
  2. Whey protein isolates: Produced through various filtration techniques to produce a product with 90% protein concentration or more, with minimal lactose and fat.
  3. Whey protein hydrolysates: A production technique that “pre-digests” the protein to increase the absorption rate. It causes a 28-43% greater insulin spike compared to whey isolated.4


Beware of the "grass-fed" claim trap!

Virtually every dairy cow feeds on at least some grass but how much? Always look for a credible and specific grass-fed claim. Unscrupulous companies rely on your ignorance to get away with their claims. Feeding cows grass 10 days out of the year should not allow them to make a “grass-fed” claim.

DIESEL is open and transparent about our happy cows. We have a credible, validated grass-fed statement that is routinely audited by 3rd party auditors. We source our protein from one of the largest dairy producers in the world and when they say grass-fed, it means more than 90% of feeding is grass and >80% time grazing on pasture.

Our grass-fed claim is important to us because we know that it’s important to you and your health.

Why is grass-fed whey isolate the best option after bariatric surgery?


A high-quality grass-fed whey protein isolate is often the choice for bariatric surgery patients for a few reasons3:

  1. High biological value (104), which is the degree to which the body can utilize the protein
  2. It contains the highest concentrations of leucine to maximize uptake and muscle protein synthesis
  3. High level of essential and branched-chain amino acids (BCAAs)
  4. Minimal lactose to avoid gastric distress (gas, bloating, abdominal cramping)
  5. It contains other biological compounds (lactoferrin, immunoglobulins, lactoperoxidase, glycomacropeptide, and bovine serum albumin) that may promote a healthier BMI by enhancing muscle mass and decreasing fat mass
  6. High protein content per serving

Because bariatric patients are at a high risk of protein deficiency, implementing a nutritional strategy that addresses the main nutritional concern is essential. And studies show that compared to patients not consuming a protein supplement, those who consumed a protein supplement saw significant improvements in body composition by enhancing body fat loss and reducing loss of lean body mass.5

And if you choose a clean and pure whey like DIESEL Whey Protein Isolate, you’re getting all that plus a product that’s low in sugar, free of artificial ingredients and sweeteners, naturally flavored, and contains only grass-fed whey derived from New Zealand pasture-raised cows.



Bioavailability is key!

Looking for quality means looking for whey protein isolate that has a declaration of how much of the bioactive whey fractions it has, like alpha lactalbumin and beta lactoglobulin.

Key takeaways


Gastric bypass surgery is a pivotal moment in many people’s life and marks the pathway to health—but it’s not as simple as getting surgery, and everything is perfect. While much of the excess weight is gone, there are still other things to battle—muscle loss, continued weight loss, wound healing, and sagging skin. And although there’s no magic pill for recovery, grass-fed whey isolate comes close. Bariatric surgery patients are at high risk for protein deficiency, and supplementing with whey isolate can help prevent loss of muscle tissue, accelerate wound healing, enhance fat metabolization to maintain weight loss, support tissue repair, and more.

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  1. Bertoni L, Valentini R, Zattarin A, et al. Assessment of Protein Intake in the First Three Months after Sleeve Gastrectomy in Patients with Severe Obesity. Nutrients. 2021;13(3):771. Published 2021 Feb 27. doi:10.3390/nu13030771
  2. ElSherif MA, Al-Shamari SD, Hamid W, Hanna F. The effect of protein supplementation on body muscle mass and fat mass in post-bariatric surgery: a randomized controlled trial (RCT) study protocol. Arch Public Health. 2018;76:7. Published 2018 Jan 22. doi:10.1186/s13690-017-0252-2
  3. Hoffman JR, Falvo MJ. Protein – Which is Best?. J Sports Sci Med. 2004;3(3):118-130. Published 2004 Sep 1.
  4. Power O, Hallihan A, Jakeman P. Human insulinotropic response to oral ingestion of native and hydrolysed whey protein. Amino Acids. 2009;37(2):333-339. doi:10.1007/s00726-008-0156-0
  5. Schollenberger AE, Karschin J, Meile T, Küper MA, Königsrainer A, Bischoff SC. Impact of protein supplementation after bariatric surgery: A randomized controlled double-blind pilot study. Nutrition. 2016;32(2):186-192. doi:10.1016/j.nut.2015.08.005
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Shea Pierre – Coach and Owner of Pierre’s Elite Performance

A Father & Loving Husband First, Sports Performance Coach, Former Professional Football Player, Entrepreneur and Motivator second. Shea went from training athletes in his basement, to being a head college strength and conditioning coach to then become the head strength and conditioning coach of the Toronto Argonauts in the CFL. He has now spread his knowledge to 50,000+ elite athletes worldwide and continues to be a go-to strength coach for professional athletes.