Protein is a common cause of bloat. That's because most types of protein contain potential gut irritants like casein, lactose, or fiber which could cause excessive fermentation in some people.1,2,3,4 The common symptoms associated with protein bloat are: abdominal pressure, nausea, belching, flatulence, fatigue, stomach pain and diarrhea.
Read below as we discuss the types of protein that may cause digestive issues and options that could support your digestion.
What Protein Types Cause The Most Bloat?
1. Whey Protein
Popular among fitness communities, whey protein is derived from whey, a by-product of cheese manufacturing. This means that it's from cow’s milk, making it unsuitable for vegans. It also contains all the essential amino acids required by the body.
There are immense benefits of taking it — it supports an improved immune system5 and muscle growth — but whey contains small amounts of lactose, which is hard for some people to digest.1 The condition, called lactose intolerance, results in bloat, abdominal upset, and discomfort.
2. Soy Protein
Unlike whey, soy protein is isolated from soy-bean, a legume, and can be a good protein choice for vegans. Soy protein has been available for consumption since 19596 and is considered a complete plant source of protein. It contains all essential amino acids, and consuming it reduces the risk of coronary heart disease, cancer, obesity, and diabetes.7
However, there are claims that soy protein can block thyroid hormone production and lead to hypothyroidism (low thyroid function) or thyroiditis (thyroid autoimmune disease).4 Soy also contains phytate, which can inhibit mineral absorption.4
3. Casein Protein
Casein is another protein source that's derived from milk8 and most commonly found in large amounts in cheese. Like whey, it has a high concentration of amino acids but is lower in lactose, a major cause of bloat. Casein is the major allergen from dairy and so, can cause allergies for some people and it is not suitable for vegans.2
4. Hemp Protein
Hemp protein is derived from cannabis seeds. It has high levels of fiber, zinc, iron, magnesium and amino acids.9 But studies differ on whether hemp is a complete protein source or not. Some studies conclude that hemp has all the nine essential amino acids while others don't.10,11,12 Hemp might not be the best choice if you're prone to digestive upset, because it contains higher amounts of fiber which can be irritating for people with a sensitive gut.
What Protein Type Support Less Bloat?
Pea protein is made from peas, which makes it a great choice for vegans. It contains all the essential amino acids needed by the body and its protein content is high.13 Like whey, pea protein stimulates muscle growth and is also a great source of iron and fortifies the body against deficiency-related diseases.14 Fortunately, pea protein doesn't contain casein, or appreciable amounts of lectins or phytic acid — usually present in legumes that cause bloat. So if you're bothered by digestive issues, pea protein is a great choice.
Clean Lean Protein is made from golden peas that undergo a water-based isolation process that effectively removes lectins and phytic acid from the protein. Clean Lean Protein also has a 98% digestibility rate and contains no artificial ingredients. You can also try Clean Lean Protein Digestive Support, which is blended with probiotics and other gut-friendly ingredients for healthy digestive support.
- Dean and Wheeler (2006) IBS For Dummies. Wiley Publishing: Indiana.