UK Coffee Chains Race to Add Protein to Lattes and Drinks

Protein has escaped the gym. It is no longer the exclusive domain of bodybuilders or fitness obsessives. Now, it is hiding in your bagels, your breakfast cereal, and even your coffee. The trend has swept through the UK high street, with major chains racing to pack muscle-building nutrients into their daily menus.

Starbucks has added protein-enhanced drinks to its British lineup. Costa is trialing lattes that contain 23g of protein, a quantity roughly equal to what you would find in a small chicken breast. This month, Caffè Nero partnered with sports nutrition brand Myprotein to release iced lattes boasting up to 25g of protein. The promise is simple: a substantial dose of the nutrient alongside your caffeine fix.

For most people, the body can get everything it needs from a daily chicken breast or a couple of eggs. But is a liquid top-up worth the investment? Registered nutritionist Emma Bardwell breaks down the facts. Protein is one of the three main nutrients, sitting alongside carbohydrates and fats. It is essential for building and repairing muscles, keeping skin supple, maintaining strong hair, and producing vital hormones.

Bardwell notes that protein is necessary to sustain all muscle types. This includes skeletal muscles, the muscles that allow your heart to beat, and the muscles that open up your airways so you can breathe.

The NHS recommends adults eat 0.75g of protein per kilogram of body weight daily. For someone weighing 70kg, that works out to about 52.5g. Think two medium chicken breasts or two scoops of protein powder. However, Bardwell suggests healthy, active midlife and older adults aim higher. She recommends consuming around 1.2–1.6g per kilogram of body weight, depending on activity levels.

Why the increase? As we age, the body becomes less efficient at using dietary protein to build and maintain muscle. We need more to preserve strength and mobility. This could push daily needs to 84–112g. That is the equivalent of three and a half tins of tuna or a large pot of Greek yoghurt.

There is a catch. Too much protein can overload the kidneys. Experts say the danger mostly concerns those who already suffer from kidney problems. These patients are advised to limit intake to around 0.55-0.8g/kg per day. That is roughly 52g for the average woman and about 64g for the average man.

But the risk is not limited to the elderly or the ill. Experts have recently warned of a rise in otherwise healthy, young people developing kidney stones due to super high-protein diets. Kidney stones are small, hard lumps of salts and minerals, such as calcium. They can be symptomless until they move into the ureter, the tube carrying urine from the kidney to the bladder. There, they cause excruciating pain. If lodged, the situation can become life-threatening.

Vimoshan Arumuham, a consultant urological surgeon at University College London Hospital, explains the mechanism. "Eating a lot of protein makes urine acidic," he said. "This raises the amount of uric acid in it but also increasing calcium (partly because the acid leads to calcium being released from bone), and lowers citrate, a stone inhibitor (found naturally in the body). This means stones form more easily."

So, which is healthier: protein shakes or everyday foods? A typical shake delivers around 20–25g of protein. By comparison, 100g of cooked chicken breast provides approximately 32g. Two large eggs contain around 12–13g. You would need to eat four eggs to match a shake. Then again, a shake can be rustled up in seconds. Bringing a pan of water to the boil takes much longer.

Bardwell is clear on absorption. "Your body can digest and absorb protein from shakes and solid food equally," she explains. Gram for gram, protein powders can actually work out cheaper than ordinary foods. The choice ultimately comes down to convenience versus cost, but the physiological impact remains the same.

Tesco charges £1.40 for four large free-range eggs. That batch delivers roughly 31g of protein. Sainsbury’s own-brand powder gets you the same muscle-building fuel for about £1.12. You save 28p. But money isn’t the only metric here. Those eggs carry choline and vitamin B12, nutrients the powder might completely lack.

Do shakes actually fill you up? Probably not as well as real food. Bardwell points out that solid foods trigger satiety signals more effectively. Chewing matters. The time spent eating matters. A shake might boast 25g of protein, yet it rarely satisfies the way a meal does, especially one packed with fiber and healthy fats.

Whey protein moves through your system fast. Whole-food proteins move slowly. They are part of complex matrices that resist rapid digestion. This timing difference creates a trap. A protein shake can hide hundreds of calories behind a liquid curtain, offering less fullness than a simple frittata with beans. If weight loss is the goal, that gap in satiety is dangerous. You become vulnerable to snacking. Total daily calories creep up. Weight gain follows.

The strongest case for whole foods isn't just taste; it's density. Greek yoghurt brings calcium and B12. Eggs offer choline. Salmon supplies omega-3s. These "natural added extras" do heavy lifting for your health. Fiber is the star of that show. It supports digestion and links to a lower risk of chronic issues, including bowel cancer. Most UK adults fall well short of the NHS-recommended 30g daily. Swapping meals for shakes shrinks your chances of hitting that target.

Walk down any supplement aisle and you’ll see a dizzying array of claims. Faster recovery. Better skin. Healthier hair. Whey dominates the shelf. Derived from milk, it contains all nine essential amino acids. Sports nutritionists often crown it the gold standard. Why? Leucine. That specific amino acid triggers muscle protein synthesis, and whey is loaded with it.

Casein offers a different pace. Also from milk, it digests slowly. It supports muscle maintenance and growth, particularly when taken at night. Then there are the processed variants. Whey isolates undergo extra filtration to strip out fat and lactose. Hydrolysed proteins break down partially to speed up absorption. Does that complexity help the average person? Bardwell says no. Unless you have a specific medical or digestive need, there is little convincing evidence that hydrolysed protein yields better results.

Plant-based options have their own quirks. Soy packs all nine essential amino acids. Pea protein misses out on some. But variety solves that problem. Eating different plant proteins throughout the day closes the nutritional gap.