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Is your protein powder causing bloating and stomach pain?

Posted by for Nutrition

Bloating and gas is a commonly complained about side-effect from protein shakes. But what’s really causing the discomfort? 

If you’ve been experimenting with supplements, you may have experienced the “protein bloat”. Regular shake-drinkers or gym-goers might also know about the reality of “protein farts”. These phenomena raise the question: are protein powders causing havoc on our digestive system?

“Consuming too much of any protein can cause it to be mal-absorbed,” says Dr Megan Rossi aka the Gut Health Doctor. “Excess protein can also lead to smelly gas due to the bacteria fermentation.”

Studies show that diets high in excess protein can contribute to digestive discomfort, but that is after to chronic consumption over a long period of time. A 2016 review from the Royal College of Chemistry noted that while some people on high-protein diets may experience digestive side-effects, “healthy individuals have a high capacity to oxidize dietary amino acids and protein.” It concluded: “Long-term consumption of any nutrients (including water, protein, and vitamin A) in high amounts may have adverse effects on human health.” 

So why might protein supplements cause some people immediate aggravation? The most popular protein powders are whey and vegan alternatives. Whey powder comes from cow’s milk, a byproduct of cheese making. Vegan protein powders are made from a whole range of plants, such as soy, pea and rice. If you’ve tried one before, you know that they don’t taste savoury or cheesy. The supplements actually come in all sorts of flavours – browsing a supplement site is similar to visiting an ice cream emporium. 

A woman making a smoothie with lots of fruit
Protein drinks can cause aggravation if they're loaded with fruits.

This might be the first problem, says Dr Rossi. “It can be common for people to experience stomach issues after having protein supplements, depending on the ingredients and also what they mix with them. They’ll often contain polyol sweeteners such as sorbitol and xylitol which can contribute to bloating and excess gas as they are poorly absorbed by the body,” she says.

While whey tends to get a worse rep for causing digestive issues than the vegan alternatives, Dr Rossi says this is apparently not because whey is tougher to digest (unless you are lactose intolerant or have a cow’s milk allergy) but perhaps just because it’s a more widely drunk supplement. 

How and when you drink them can also be a cause of bloating, gas or pain. “Some blend them with several pieces of fruit, which for some can overwhelm their bodies ability to digest the fructose aka fruit sugar, at once – it is best to space fruit out across the day,” says Dr Rossi.

Plus, we most commonly drink protein supplements after exercise. During this time, our body is usually in a state of stress, which can lead to digestive discomfort. “Eating when stressed can trigger gut symptoms, irrespective of what you are actually eating,” acknowledges Rossi.

A study from the International Society of Sports Nutrition journal found that when training at 70% of your maximum capacity, blood flow to your digestive system is reduced by almost 80%. Plus, that level of training was also shown to delay gastric emptying (essentially, slow the movement of food through the bowels) and lead to symptoms including nausea and cramps. 

How to avoid bloating and discomfort when using protein supplements

Get your protein from whole food sources – there’s nothing magical about a protein powder, and while they may be convenient, opting for lean meats, beans, legumes or dairy products limits the amount of gut-aggravating ingredients.

Check the ingredients – opt for a powder that’s flavoured with natural flavourings or sweeteners you know you can stomach.

Stick to one serving – of both protein and fruit in one go.

Limit stress – that might mean waiting for a bit after training before taking supplements, until your body is out of the state of stress. Don’t worry about your gains – the anabolic window isn’t really a concern. 

Images: Pexels / Getty

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Chloe Gray

Chloe Gray is the senior writer for stylist.co.uk's fitness brand Strong Women. When she's not writing or lifting weights, she's most likely found practicing handstands, sipping a gin and tonic or eating peanut butter straight out of the jar (not all at the same time).

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