\u201cMaking a truly harmful protein bar is a way of showing how easy it is to put really unhealthy ingredients into a bar and sell it to you as a health food,\u201d Wicks wrote. \u201cProtein has become this thing that\u2019s in everything \u2014 yoghurts, crisps, chocolate bars. But so many of them have additives, chemicals, sweeteners, gums, emulsifiers. A sandwich has probably got more nutrition than a protein bar. It\u2019s basically all chemicals, just powders. There\u2019s no food in it.\u201d <\/p>\n
They aren\u2019t the first to raise concerns. This year Dr James Kinross, consultant colorectal surgeon at Imperial College London and author of Dark Matter, the New Science of the Microbiome, warned about the dangers of protein shakes, saying: \u201cThese protein powders are bad news and really bad for your gut.\u201d<\/p>\n
He notes: \u201cEssentially, a very high-protein diet makes bacteria in the colon behave differently and not always in a good way. This is because some of the metabolites it produces are very toxic and we know that these cause harm or even cancer.\u201d<\/p>\n
The reaction \u2014 from some industry manufacturers and colleagues \u2014 was, he says, \u201ca little hostile\u201d. But he remains unrepentant.<\/p>\n
\u201cThese powders are marketed egregiously to young people,\u201d Kinross says. \u201cWe\u2019re seeing a rapid rise in the use of these powders by teenagers \u2014 mostly boys \u2014 and twentysomethings.\u201d <\/p>\n
\u2022 Have we reached peak protein?<\/a><\/p>\n Even if they look buff, he says, what about their insides? \u201cJust because you\u2019ve got lots of muscle, that doesn\u2019t necessarily imply you\u2019ve got a healthy gut,\u201d Kinross says. And while existing research suggests protein powders are safe, he adds: \u201cWe just don\u2019t have any good quality evidence for the long-term health consequences of protein powders taken by teenagers.\u201d<\/p>\n Here he explains what parents need to know. <\/p>\n You can get all the protein you need from food Banana oatmeal smoothies deliver high-quality protein, carbs and hydration<\/p>\n GETTY IMAGES<\/p>\n \u201cWe all need protein,\u201d Kinross says. Amino acids are the building blocks of the human body and some are essential, meaning we can only get them from food, but many are actually eating too much of it.<\/p>\n My son favours tuna, eggs, chicken, beef \u2014 often eating meat twice daily: what in gym culture is called \u201cgains-associated eating\u201d (for bulking muscles) seen in those more likely to use protein supplements, Kinross says. Adults actually need roughly 0.75g protein per kilo of bodyweight a day. For the average adult man that\u2019s 55g, or 45g for women, according to the Department of Health. <\/p>\n So what does that look like? A chicken breast contains about 45g protein, an egg about 6g, a 100g portion of Greek yoghurt about 10g, and \u2014 though there\u2019s a fat chance of my son trying it \u2014 100g cooked quinoa contains about 4g protein. If teens are particularly active, they could have up to 1g protein per kg of bodyweight a day, Kinross says, but anything over 1.5g\/kg a day is considered a high-protein diet. <\/p>\n \u201cYou should only be eating this if you\u2019re either an athlete, or this has been recommended by your doctor, eg for weight loss,\u201d Kinross says. \u201cMore than 2g\/kg per day consumed for long periods of time increases the risk of multiple adverse health effects, some of which include kidney stones, renal or liver injury, acne, altered mood, an irritable bowel, and possibly some types of cancer.\u201d <\/p>\n \u2022 How much protein do I need a day? Probably less than you think<\/a><\/p>\n Too much protein can harm your gut<\/p>\n Protein is usually slowly digested in the stomach and small intestine over 3 to 6 hours, which is why it makes us feel full. But if you overeat protein \u2014 the average UK adult consumes about 76g daily before you add in any supplements, Kinross says \u2014 about 10 per cent reaches the colon where it\u2019s fermented by bacteria. <\/p>\n \u201cIf we eat too much protein this fermentation produces molecules that can be harmful,\u201d Kinross says. \u201cProtein consumption increases the total number of bacteria in the gut, but it also influences the type \u2014 typically more clostridia and E. coli \u2014 and the functions of bugs which in turn make molecules \u2014 like ammonia, nitrosamines, or sulphides \u2014 which are quite toxic and damaging to the gut lining, causing inflammation and even cancer.\u201d <\/p>\n There\u2019s too much focus on protein \u2014 teens need more fibre<\/p>\n Dumping protein powder into a blender instead of eating a meal appeals to the teenager who finds \u201cnutrition\u201d confusing \u2014 or who can\u2019t be bothered to heat up your bean chilli. \u201cBut packing your body with a powder is much, much less good for you than having a more natural food that has protein in the way your body needs to digest it,\u201d Kinross says. \u201cOne of my other anxieties about too much focus on protein is the \u2018fibre\u2019 gap. The average person in the UK eats about 16g of fibre a day when we should be eating about 30g per day. We simply do not eat enough of this precious, plant-based food.\u201d Just 7g per day more \u2014 there\u2019s 2g in an apple \u2014 will reduce your risk of diseases like cancer, cardiovascular disease, diabetes and stroke. \u201cIt\u2019s the cornerstone of a healthy diet,\u201d he adds.<\/p>\n What are protein powders?<\/p>\n Protein from food is \u201ca collection of lots of amino acids linked together folded into a molecule\u201d, Kinross says. \u201cSome powders are the whole protein and others are simple amino acids, just one of those building blocks in a refined powder.\u201d<\/p>\n The king of protein powder supplements is whey, a protein derived from milk, and most frequently used by adolescents and adults who train. It can be bought as isolate (filtered from fats and carbs), concentrate (higher calorific content), and hydrolysed (readily absorbed and less likely to cause allergies), which reflect how processed it is. Another common milk protein is casein, which contains nine essential amino acids and is slowly digested. Increasingly popular is hydrolysed collagen \u2014 a connective tissue taken from the skin, bones and tendons of cows, pigs, chickens and fish, broken down into smaller peptides. Vegetable proteins \u2014 from peas (rich in branched-chain amino acids), soy, brown rice, sunflower and pumpkin seeds \u2014 are less popular.<\/p>\n![\"Banana](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/10\/\/79cada8c-1854-403e-bb46-24e91987052e.jpg\")
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