Protein powders are big business. In 2024 the global market for them was valued at $24.6 billion; by 2034 it’s projected to reach $46.2 billion. Not only does any self- respecting gym offer post-workout protein shakes, but giant tubs of powders are now available in supermarkets. Certain social media influencers would have us believe a scoop of sweetened powder is the holy grail for getting stronger and leaner.
Really? “I don’t think they’re a scam,” says Dr Rupy Aujla, the author of the Healthy High Protein cookbook. “But they are unnecessary for a lot of people.”
The official advice in the UK is that adults should eat 0.75g of protein per kg of body weight, which translates to 56g a day for a man weighing 75kg and 45g for a woman weighing 60kg, although recent research shows adults aged 65 and over may require as much as 1.0-1.3g to maintain muscle mass. If you’re working out to build muscle, evidence suggests the optimum amount is 1.2-1.6g.
Protein powders are a quick way to get your fix. A standard scoop contains 20-30g of protein, comparable to 100g of cheddar cheese or about 100g of mixed nuts and seeds. Still, it’s easy enough to incorporate protein into your diet without resorting to artificial stuff. A chicken breast provides about 30g, 100g Greek yoghurt provides 10g and an egg 6g.
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Vegans, or the lactose intolerant, might find it harder. “Beans and lentils are touted as high in protein but contain only 8-10g per 100g, which is quite low considering a lot of us would benefit from 25-30g per meal,” Aujla says. “In these cases, powders can be useful.”
Drinking a shake is also easier than carrying around a chicken breast for after the gym. Fitness studios know this, which is why they upsell the drinks. Take Barry’s, which has nine studios in the UK and offers a Coco Loco shake that includes protein powder, chia seeds, almond butter and coconut milk for £8.50. “It’s a lovely money-spinner,” Aujla says.
It is unclear whether there are specific benefits to drinking a shake after a workout. “We used to believe in this thing called the anabolic window, a period after exercise when your body is waiting to absorb amino acids [the building blocks of protein],” Aujla says. “It was thought you had 60 minutes to get your protein in, but we now know that muscles remain sensitive for upwards of 20 hours.” He does not buy smoothies or shakes. “They’re full of sugar.”
Indeed, the flavours of some of these powders — chocolate cookie, salted caramel, banoffee — do not sound healthy. “They are all processed, as processing is required to make whey protein, a by-product of cheese, or plant-based protein from soy, corn, rice or peas,” Aujla says. “They become ultra-processed when you add emulsifiers, additives, gums and sweeteners. But there are one-ingredient protein powders that are simply made from whey or a blend of plant proteins to provide all nine essential amino acids.”
If you’re increasing your protein through food, you’re unlikely to overdo it, but if you’re chugging back protein shakes on top of a protein-heavy diet, it might even do some harm. Excessively high levels of protein can lead to liver and kidney problems. And last year the US non-profit the Clean Label Project tested 160 protein powders from 70 top-selling brands and found 47 per cent were unsafe, containing lead, cadmium, arsenic and mercury.
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“It’s the industry’s dirty secret,” Aujla says. “There are heavy metals and pesticides because when you’re concentrating whey or plant-based protein, any contaminants will be concentrated in the end product.” He recommends buying organic if you can.
The upshot is: protein powders can be useful for those who want to build muscle, older people, vegans and anyone who struggles to get protein through lack of appetite (perhaps due to medication). But not all of them are created equal. Always read the label, and choose an unflavoured, ideally single-ingredient product that has been independently tested. “They can help some people, in some situations,” Dr Aujla says, “but the preference is always to get your protein from food.”