Learn about how to prevent nausea and vomiting when consuming protein supplements.

What are the common concerns of protein supplementation post-bariatric surgery?

Bariatric surgery can be life-changing for individuals struggling with obesity. However, after the surgery, it is essential to follow a high-protein diet to support healing and promote weight loss. While protein supplements are an excellent option to meet daily protein requirements, there are some things to keep in mind when you increase your protein intake. 

In this article, we will discuss some things to consider when consuming a high protein diet, ways to prevent nausea and vomiting when consuming protein supplements, and the differences between whey, collagen and plant-based protein for bariatric patients. We will also explore whether bariatric protein supplementation can lead to constipation or other digestive issues.

Consuming a high protein diet after bariatric surgery can have some potential side effects. To prevent these, here are some suggestions

  • Dehydration: Increase fluid intake if consuming large amounts of protein to prevent the risk of dehydration.
  • Digestive issues: Consuming a high protein diet can cause digestive issues, such as bloating, constipation, and diarrhea. Eat protein in small amounts, frequently throughout the day. Consider the type of protein, the presence of lactose or artificial sweeteners and modify if there are intolerances. 
  • Nutrient deficiencies: Consuming large amounts of protein may lead to a decreased intake of other essential nutrients, such as carbohydrates, fiber, and certain vitamins and minerals so remember to take your multivitamin and eat foods high in fiber. 
  • Weight gain: Consuming too much protein can lead to weight gain, as excess protein can be stored as fat in the body. Follow your healthcare providers guidelines to the amount of protein you need. 

It's important to follow the recommendations of your healthcare provider or registered dietitian when it comes to protein intake after bariatric surgery. They can help you determine the appropriate amount of protein for your individual needs and monitor for any potential side effects.

How can I prevent nausea, vomiting and constipation when consuming protein supplements?

Nausea, vomiting and constipation can be a common side effect after bariatric surgery. Here are some tips to help prevent nausea and vomiting and constipation.

  1. Start with small amounts: Begin with a small amount of protein supplement, such as a few sips or a tablespoon, and gradually increase the amount over time as tolerated. A concentrated liquid protein can help reduce the volume needed to get the recommended amounts of protein.
  2. Sip slowly: Drink the protein supplement slowly, taking small sips and allowing time for your body to adjust.
  3. Avoid drinking with meals: Wait at least 30 minutes after a meal before consuming a protein supplement to reduce the risk of nausea and vomiting. Wait 30 minutes after taking a protein supplement to drink additional fluids.
  4. Drink plenty of water: Ensure adequate hydration by drinking water throughout the day, as dehydration can increase the risk of nausea and vomiting and constipation.
  5. Choose the right protein supplement: Some protein supplements may be easier to digest and less likely to cause nausea and vomiting. Experiment with different types of protein supplements, such as whey, collagen or pea protein, to find one that works well for you. Take a supplement that is low volume and contains a small amount of sugar. 

People with trouble digesting lactose( milk sugar) may experience gastrointestinal distress if they use a milk-based supplement. Soy lecithin can also cause nausea, diarrhea or stomach pain. Artificial sweeteners and sugar alcohols can cause GI distress.

If you continue to experience nausea and vomiting or constipation when consuming protein supplements, speak with your healthcare provider or registered dietitian. They may recommend adjusting the timing, amount, or type of protein supplement, or suggest alternative strategies to increase your protein intake.

Can I consume regular protein supplements after bariatric surgery?

Regular protein supplements may not be appropriate for bariatric patients, as they can be difficult to digest and may not provide the necessary nutrients. Bariatric patients require protein supplements that are specifically formulated for their unique nutritional needs.

Protein supplements for bariatric patients are typically low in carbohydrates, fats, and calories, and may contain additional vitamins and minerals to help meet nutritional needs. They may also be in a liquid or powder form, which can be easier to digest.

It is important to consult with a healthcare provider or registered dietitian before starting any protein supplement after bariatric surgery. They can help you determine the appropriate type and amount of protein supplement based on your individual needs and goals. Additionally, they can provide guidance on how to incorporate protein supplements into your overall diet plan to help ensure adequate nutrition and promote optimal health.

What is the difference between whey, collagen protein and plant-based protein for bariatric patients?

Whey protein, collagen, and plant-based protein are the three common types of protein supplements that bariatric patients may consider. The main difference between them is their source and nutrient content.

Whey protein is derived from milk and is a complete protein, containing all nine essential amino acids that the body needs. It is quickly absorbed by the body, making it a popular choice for athletes and bodybuilders.

Collagen is derived from animal sources such as beef and does not contain sufficient amino acid tryptophan to be a complete protein. It can be part of a complete protein if it contains added tryptophan or is combined with whey protein. Collagen has been shown to improve skin elasticity and be beneficial to joint health.

Plant-based protein is derived from sources such as soy, pea, rice, and hemp. While some plant-based proteins may not be complete proteins, consuming a variety of plant-based protein sources can provide all the essential amino acids needed by the body.

Ultimately, the choice between whey, collagen, and plant-based protein supplements for bariatric patients may depend on individual dietary preferences, tolerances, and nutritional needs. It is important to consult with a healthcare provider or registered dietitian before making any significant changes to your diet or supplement routine.

In conclusion, protein is essential for bariatric patients and plays a crucial role in their post-surgery recovery and long-term success. However, it's essential to consume the right amount and type of protein to avoid potential digestive issues. By following the guidelines discussed, bariatric patients can make informed decisions about protein supplementation and ensure they are meeting their nutritional needs. Remember to always consult with a healthcare professional before making any significant changes to your diet or exercise routine.



  1. "Protein Supplements and Bariatric Surgery Patients: What You Need to Know" by the Obesity Action Coalition.https://www.obesityaction.org/wp-content/uploads/Protein-Supplements-1.pdf 
  2. "Whey Protein vs. Plant-Based Protein: What's the Difference?" by Healthline. https://www.healthline.com/nutrition/whey-vs-plant-protein 
  3. "Gastric bypass surgery patients need lifelong protein supplementation" by the American Society for Metabolic and Bariatric Surgery https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5347111/