Thousands following high-protein diets promoted by social media influencers are putting themselves at risk of incurable organ failure, warn experts.
Fitness gurus on TikTok and Instagram routinely urge followers to dramatically increase their protein intake to aid weight loss and build muscle.
The craze has led to a boom in protein products, such as shakes, bars and powders, with 56 per cent of UK consumers actively seeking protein-rich food and drink, according to a 2024 study.
But experts have warned that though for most people high-protein diets are safe, for around one in ten the trend can trigger life-threatening kidney disease.
The ‘silent killer’ condition does not have symptoms until the kidneys begin to fail, meaning many people could suffer it without realising. Experts say that, for this reason, most people should avoid eating above the NHS-recommended amount of protein.
‘Protein puts a lot of stress on the kidneys because the organ struggles to process it,’ says Dr Carl May, a kidney expert at University of Bristol. ‘So consistently eating above the recommended amount is going to be tough on them.
‘For around nine out of ten people, this won’t lead to anything serious. But that unlucky 10 per cent could be quietly damaging their kidneys without realising it.
‘This means those patients may be creeping towards kidney failure. If that happens, you’re probably looking at an organ transplant.’
Experts agree that protein is a crucial component of a healthy diet. The nutrient helps repair and build muscle fibres, organs and connective tissue. It also regulates hormones and boosts immunity.
Experts agree that protein is a crucial component of a healthy diet…
… but they have warned that for around one in ten the trend can trigger life-threatening kidney disease
It can be found in animal products – such as chicken, beef, fish, eggs and dairy – as well as plant-based foods such as lentils, chickpeas, tofu, nuts and seeds.
The NHS recommends adults should eat about 0.8g of protein per kilogram of body weight per day. This is around 55g for the average man and 45g for the average woman.
But, in recent years, influential figures have suggested that eating double or even triple this amount is a route to better health.
Chief among them is Dr Peter Attia who has more than three million followers on social media. He recommends people aim for 2g per kilogram per day – more than double the NHS recommendation. He has labelled current protein intake guidance as ‘pathetic’, arguing that it is not enough to maintain muscle mass in later life.
Supermarkets have also leaned into the high-protein trend.
In 2024, M&S launched a ‘High-Protein’ range which included protein-rich sandwiches, yogurts, salads, snack bars and a ‘high-protein skimmed milk’.
Tesco, Aldi, Lidl and Iceland have also promoted high-protein products in recent years.
But experts advise against going on a high-protein diet without consulting a doctor.
Growing evidence suggests eating above NHS-recommended protein levels could be harmful for those more vulnerable to kidney disease, which affects more than eight million Britons, though around half are undiagnosed.
By the time that symptoms appear, including fatigue, swollen joints, itchy skin and frequent urination, the organ is damaged beyond repair.
Research suggests kidney disease treatment costs the NHS more than £1.4billion a year.
‘Some have a gene mutation which means excess protein can stress the kidneys,’ says Dr May.
‘This can cause scarring and lasting damage. The problem is that no one knows they carry this gene until they get kidney disease.’
Studies show that once patients develop kidney disease, continuing to eat a high-protein diet can significantly increase the chances of needing dialysis or a transplant.
An Israeli study last month showed kidney disease patients who consume even just a few grams more protein than the UK average are around a third more likely to progress to develop the most severe form of the condition.
Experts say patients with diabetes and high blood pressure are most at-risk of kidney disease.
The toll of UK kidney disease patients is expected to rise by 400,000 in the next decade, largely due to the obesity crisis which has triggered a massive increase in the number of diabetes and high blood pressure patients.
Spotted early, progression of the disease can be halted with medication. GPs can do a blood test, called an eGFR check, which can identify early signs of the disease.
‘There are more than one million people in the UK who have chronic kidney disease without realising it,’ says Fiona Loud, policy director at Kidney Care UK.
‘It’s important that, if you have high blood pressure or diabetes, you ask your GP to test your kidney function.’
