Protein powders and IBS


Dakota Rhys-Jones - Research Dietitian, 04 March 2021

We get lots of questions here at Monash FODMAP about different protein powders asking if they are safe to consume on the low FODMAP diet. Unfortunately, we cannot provide clear answers regarding FODMAP content without testing each individual protein powder. However, we can provide you the basics on protein, protein supplementation and how this is relevant for someone with IBS.

Physiological function of protein

Protein is an essential component in the diet – it is found in all the cells of our body, makes up important hormones/enzymes, and is essential for muscle repair and regeneration. Protein is different from other macronutrients (i.e. carbohydrates/fats) in the diet, because it cannot be stored like they can. Instead, proteins are broken down into amino acids (the building blocks of protein), and continuously turned over in the body. Our body is continuously building up and breaking down proteins, and any excess dietary protein gets excreted mainly in the urine.

Who needs protein supplementation?

Most people eat more than enough protein through diet alone, and do not have to supplement with extra protein through supplements or protein powders (1). Some population groups require additional protein due to higher protein requirements or being at higher risk of nutritional inadequacy including: elderly, those following a vegan/vegetarian diet, certain athletes, pregnant and lactating women, and for certain medical reasons (i.e. post-surgery/wound healing/infections).

There is no evidence to suggest that having IBS will contribute to extra protein requirements or that following a low FODMAP diet will impact protein intake significantly. Many protein sources (e.g. meat/eggs/chicken) are naturally low in FODMAPs and a recent study found that protein intake remained consistent when moving from habitual diet to a low FODMAP diet (2).

Protein powders & FODMAPs:

Through our experience testing protein powders, we have found that extracting pure protein is challenging for food manufacturers and these products are often high in FODMAPs. While these products can contain anywhere between 70-90% protein, it only takes a small amount of FODMAPs to cause symptoms in individuals with IBS. The ingredients lists can be full of unknowns and without laboratory analysis of the product, it becomes extremely challenging to predict FODMAP content based on a label. Unless specified by a health professional to take a protein supplement, our general advice is to stick to food options first for protein intake (see table below).

Things to look out for when purchasing protein powder:

-          Check for polyols on the ingredients list – ingredients such as xylitol, sorbitol and mannitol are used as low-calorie sweeteners. The doses of polyols used by food manufacturers can be well above what we define as a safe serve and are likely to be problematic for those who are sensitive to sugar alcohols.

-          Plant derived proteins (e.g. soy, pea): these can be particularly challenging to purify, and often contain some FODMAPs  (eg. GOS and fructan).  

-          Look out for lactose on whey protein powder products. When comparing whey protein concentrate to whey protein isolate, isolates undergo extensive processing so that the final product is higher in protein. Whey protein concentrates are therefore lower in protein and higher in carbohydrates like lactose.

-          Avoid protein powders/supplements that have the word ‘prebiotic’ on the packaging. Prebiotic is a term synonymous with FODMAPs and it may cause symptoms for some. Check the ingredients panel for ingredients such as: inulin, chicory root, Jerusalem artichoke. Check out our blogs [1] on prebiotics about how to eat enough prebiotics from dietary sources while following a low FODMAP diet.

-          If you’re not sure, ask for a sample. Many websites offer free samples of protein powder. You can test this product on yourself before committing to the purchase and let your symptoms guide you from there.


Dietary sources of protein:

Although protein powders are extremely popular, it’s important to first focus on good quality dietary sources of protein in the diet. These include meat, fish, eggs, dairy products (lactose-free if needed), as well as vegetarian sources such as tofu, nuts, seeds and legumes (check the app for serve sizes). Including a variety of different sources of proteins throughout the day mean it’s more likely that protein requirements are being met, without the need to purchase expensive powders. Protein requirements change based on age, sex and body weight, and may be different according to your country’s guidelines. Recommended daily intakes for protein in Australia for women over the age of 18 is 0.75g/kg and for men is 0.84g/kg. The table below outlines good sources of protein found in food.

Food Source Quantity Amount of Protein
Eggs, chicken 2 x eggs 13g
Fish 100g 23g
Chicken 125g 28g
Lactose-free milk 1 cup/250ml 8g
Firm cheese 40g 9g
Tofu, firm 100g 12g
Soy milk (from soy protein) 1 cup/250ml 8g
Mixed nuts 30g 5g
Lentils, canned 50g 5g

As always, we recommend working with a trained dietitian, who can determine whether your diet is nutritionally adequate or not, and whether you may need extra supplementation. You can find our full list of Monash FODMAP trained dietitians here.



1.            ABS. Australian Health Survey: Nutrition First Results-Foods and Nutrients. Canberra: ABS; 2014.

2.            Staudacher HM, Ralph FSE, Irving PM, Whelan K, Lomer MCE. Nutrient Intake, Diet Quality, and Diet Diversity in Irritable Bowel Syndrome and the Impact of the Low FODMAP Diet. J Acad Nutr Diet. 2020;120(4):535-47.

3.            Corgneau M, Scher J, Ritie-Pertusa L, Le Dtl, Petit J, Nikolova Y, et al. Recent advances on lactose intolerance: Tolerance thresholds and currently available answers. Critical Reviews in Food Science and Nutrition. 2017;57(15):3344-56.

Back to all articles
Back to all articles