Ever wondered how a protein powder can taste dessert-sweet yet claim to be "sugar-free"? The answer is almost always sweeteners — and not all of them are as gut-friendly as the label implies.
What sweeteners are used in protein powders?
Two main families show up. High-intensity sweeteners like sucralose, aspartame, acesulfame-K and stevia add sweetness with virtually no calories. Sugar alcohols (polyols) — erythritol, xylitol, sorbitol and maltitol — add bulk and a sugar-like taste. Both let brands print "no added sugar" while keeping things very sweet.
Why brands use them
Sweeteners are cheap, calorie-light and crowd-pleasing. A sweeter shake tastes "better" on first sip and photographs well in reviews. But sweetness sells the product — it doesn't help your digestion.
Sweeteners and your gut
This is where it gets relevant for sensitive stomachs. Sugar alcohols are poorly absorbed and ferment in the gut, which is exactly why they're known for causing bloating, wind and loose stools — and why most polyols are high FODMAP. For anyone with IBS, they're a classic hidden trigger. Some research has also questioned whether certain non-nutritive sweeteners may affect the gut microbiome and blood-sugar response, though that science is still developing and far from settled.
What about stevia and "natural" sweeteners?
Stevia is plant-derived and widely regarded as safe, and many people tolerate it well. But "natural" doesn't automatically mean "gentle" — some people still notice an aftertaste or mild digestive effects, and processed stevia extracts are a long way from the leaf.
Why That Protein skips them
We use no artificial sweeteners and no sugar alcohols — none. Our blends get their flavour from real food: raw cacao, roasted peanuts, real coffee, and a touch of Palmyra jaggery in Nutty Nutty. The taste is honest rather than sugary, which is the point. No polyols also means no fermentable sweetener triggers, part of how our range stays low FODMAP and gentle.
What to choose instead
If sweeteners upset you, look for a powder sweetened by real ingredients (or not sweetened at all) and free from polyols. Pair it with naturally sweet add-ins like a ripe banana, a few berries or a date-sweetened plant milk. Our Nutty Nutty and Blissful Raw Cacao blends are good places to start.
Frequently asked questions
Do sweeteners cause bloating?
Sugar alcohols (sorbitol, xylitol, erythritol, maltitol) commonly do, because they ferment in the gut. High-intensity sweeteners affect people more variably.
Are sugar alcohols low FODMAP?
Most polyols are high FODMAP and best avoided if you have IBS.
Is stevia OK for IBS?
Many people tolerate it well, but everyone's gut is different — try a small amount first.
This article is for general information and isn't medical advice. If you have ongoing digestive symptoms, speak to a GP or registered dietitian.
References: Suez J, et al. Nature (2014) 514:181–186. Ruiz-Ojeda FJ, et al. Advances in Nutrition (2019) 10(S1):S31–S48.