Protein shakes, bars, porridges and puddings have flooded supermarket shelves lately, cementing protein’s status as the buzziest health trend. If you’ve been protein-conscious for a while, like most of those who’ve spent years in the gym likely are, you might be grateful that the world has suddenly bulked up on the nutrient to make hitting your macros much easier. After all, protein is vital for muscle growth and metabolic health – but you’d be mistaken for thinking everyone’s on board.
As with almost every trend – from zone 2 training to ice baths – there’s been protein pushback. And if your thumb has been swiping on the Reels tab, you’ll have seen many experts warning against this newfound protein obsession.
All that flip flopping probably leaves you – just a guy wanting to build some mass – feeling confused: should you be supplementing at every meal and snack, or stop worrying about your intake?
How Much Protein Do Men Need?
There’s no round number answer to the question of how much protein to eat, says nutritionist Rob Hobson. ‘The general recommendation for health in the UK for the average, sedentary man is around 0.8g of protein per kilogram of body weight per day. To put this into context, if you weigh 75kg, that’s about 60g of protein. But this is really a minimum to prevent deficiency and not necessarily optimal for maintaining muscle mass, particularly as you get older,’ he explains.
For those who are active or want to maintain strength and good metabolic health, Hobson says you need to eat more than that. The amount of extra protein you need really depends on the type and intensity of your training.
According to the International Society for Sports Nutrition, endurance athletes (like long-distance runners or cyclists) need around 1.2-1.6g of protein per kilogram of body weight per day, ‘mainly to support recovery and minimise muscle breakdown,’ says Hobson. ‘But strength or resistance trainers, like gym-goers, weightlifters and CrossFit athletes, typically need 1.6-2.2g/kg/day to maximise muscle repair and growth.
‘At the top end of this range are athletes who are in an energy deficit, like a boxer cutting weight before a competition. When calories are restricted, the risk of muscle loss increases, so protein needs often rise to around 2.2-2.5g/kg/day to preserve lean mass.’
Annabelle Breakey
Is Too Much Protein Bad for You?
The protein naysayers often come from two camps: those who say extra protein is pointless, and those who warn it’s dangerous.
Protein and Weight Gain
On the former, ‘Protein contains calories; it’s a slave to the same laws of thermodynamics as all other food,’ says Men’s Health fitness director Andrew Tracey. ‘Eat too much, move too little, and those excess calories will be stored as body fat.
‘What’s interesting about protein though, is that it has what is known as a “high thermic effect”, which means your body expends a lot of energy in digesting and absorbing it. Up to 30% of the calories you consume from sources such as chicken or chickpeas may be used in the digestion process, compared to carbohydrates and fats, which your body handles with incredible efficiency and may require less than 5% extra energy to digest and absorb.’
And Hobson says that a slight protein excess is unlikely to lead to weight gain:
‘The body first uses what protein it can to support essential functions like muscle maintenance and repair, enzyme production, neurotransmitters, and so on. Any surplus protein is broken down by the liver. The nitrogen is stripped off and excreted as urea in urine, while the remaining carbon skeletons (basically what’s left of the amino acid) can be converted into glucose through a process called gluconeogenesis, especially if your body needs more fuel such as during fasting, prolonged exercise, or low-carb intake. Or, in rare cases, it will be converted into fat – but this is metabolically inefficient and unlikely if you’re eating a balanced diet with enough carbohydrate and fat already present.’
Protein and Kidney Damage
As for the ‘danger’ of too much protein? ‘Research has shown that high-protein diets can accelerate kidney damage, but only in people with existing kidney conditions,’ says Tracey. ‘Decades of research shows no harm to kidney function from high-protein diets in healthy individuals.’ In fact, a 2024 research paper from Frontiers in Nutrition that analysed studies on over 14,000 people found that higher protein intake – from both animals and plants – was actually correlated with decreased chronic kidney disease.
‘I think many people think too much protein is damaging on the body, particularly the kidneys, but it can handle high intakes without any problem,’ notes Hobson. ‘Studies have shown that up to 3.5g/kg/day (more than 250g a day for a 75kg man) is well tolerated over extended periods without any negative health effects so long as kidney function is normal.’
Protein and Digestion
Another commonly touted side effect of high-protein diets is digestive discomfort (read: protein farts). ‘While this certainly can be an issue, it’s largely determined by the types of protein you’re consuming, as well as the foods you’re pairing that protein with,’ notes Tracey. For instance, highly processed protein drinks or snacks that contain sweeteners or other ingredients known to irritate the gut might lead to bloating, gas or diarrhea. That doesn’t mean the protein is to blame.
Others may struggle to digest some forms of whey, particularly if they are lactose intolerant or have IBS, while some plant forms of protein – like beans and soy – can contain a lot of fibre. While that’s good for you in the long run, it can take some training to get your gut used to breaking down that much roughage. Much like you wouldn’t deadlift 100kg as a beginner, you should also move slow and steady with nutritional changes.
Symptoms of Too Much Protein
While it’s highly unlikely you’ll eat too much, there may be signs that your diet needs tweaking. If you suffer from any of the below, consider re-thinking your nutrition:
- Persistent fatigue
- Digestive discomfort (bloating, constipation)
- Bad breath (from ketosis, if carb intake is also low)
- Unintended weight gain (if overall calories are too high)
‘In healthy people, high protein intake isn’t dangerous, but in people with pre-existing kidney disease, high protein can worsen kidney function due to the increased workload of filtering nitrogen waste,’ reminds Hobson.
Despite all this, Hobson still recommends some sensibility when thinking about protein intake. ‘There’s no real benefit in going above 2.2g/kg/day for the average gym-goer. It just becomes expensive, unnecessary, and displaces other important nutrients,’ he says.
How to Eat Enough Protein, Sensibly
‘Personally, I’m more than comfortable prescribing a “protein first” approach to nutrition, says Tracey. ‘At every meal, know what your protein source is going to be; make sure you’re getting at least 20-30g every time you eat. Next, add in your fruits and veg, and then let your appetite and energy levels dictate the rest.’
Hobson offers the same advice, particularly around the regularity of protein intake. ‘Most people benefit from three-to-four servings of 20-30g protein spaced through the day to help support muscle building more effectively than loading tons of it into one specific meal. That’s roughly a chicken breast, a fillet of salmon or half a pack of tofu. Use your plate as a guide: aim for about a quarter to a third of your plate to be made up of protein-rich foods.’
Most importantly, don’t over stress. It’s unlikely you’re dangerously over-eating protein, and unless you’re so full of chicken breast that you have to forego carbs, fats and micronutrients then you’re likely eating a balance diet. Or, as Tracey says, ‘Chill out and have an egg.’
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Chloe Gray is a freelance writer and editor who specialises in inclusive health and fitness. A regular contributor to Women’s Health, she is currently the Acting Health Editor and has previously held roles as our Acting Memberships Editor and Senior Writer at Stylist‘s Strong Women vertical. She studied Journalism at the University of Sheffield and has a decade of experience writing on the women’s health gap, reproductive health, mental health, diet and exercise culture and the social determinants of health for newspapers and magazines including Cosmopolitan UK, the i newspaper, Glamour, Marie Claire, Men’s Health and Red. Chloe is also a fitness trainer and coach, panelist and founder of Gray’s Anatomy, a Substack about bodies. You can follow Chloe at @graychlo.