They have become ubiquitous fixtures on British retail shelves, appearing in virtually every supermarket, local convenience store and pharmacy across the nation. Protein bars, manufactured by prominent brands including Grenade, Trek and Fulfil, are aggressively marketed as health-enhancing snacks, supposedly brimming with muscle-building protein alongside beneficial components like fibre and essential vitamins.
The Multi-Billion Pound Industry
These convenient snacks are experiencing surging popularity throughout the United Kingdom. The domestic protein bar sector has ballooned to a valuation exceeding £1.3 billion, with industry projections indicating sustained growth. This expansion is fuelled by a constant stream of new brands entering the competitive marketplace each year.
Growing Health Concerns
However, an increasing chorus of health professionals and nutrition experts is raising serious concerns about a significant dark side to these products. Last year, television fitness personality Joe Wicks highlighted these issues in his documentary, Licensed To Kill. He levelled accusations at protein bar manufacturers, claiming they deliberately load their products with excessive sugar, unhealthy fats and a cocktail of ultra-processed ingredients.
These artificial compounds, according to mounting scientific research, are associated with elevated risks of developing cancer, heart disease and dementia when consumed regularly. Academic studies appear to substantiate Wicks' alarming claims. A 2025 investigation published by Queen Mary University of London analysed over 450 snack bars, encompassing all major protein bar brands, sold across ten leading UK supermarkets.
The findings were stark: 37 percent of the bars were classified as high in sugar, while more than half contained dangerously high levels of saturated fat—a particularly harmful form linked to chronic health conditions. The research team concluded that consumers are being systematically misled by snack bar companies regarding the true nutritional value of these products.
Expert Nutritional Analysis
This perspective is strongly endorsed by London-based nutritionist Pippa Campbell, author of Eat Right, Lose Weight. "I'm not a big fan of protein bars in general and I wouldn't consider them a health food," states Ms Campbell. "There's a tremendous amount of marketing hype focused solely on protein content, but the reality is that many bars remain ultra-processed and offer minimal genuine nutritional benefit."
She concedes they can serve a purpose occasionally, such as during travel or when proper meals are unavailable, but stresses they should never replace a balanced, whole-food diet. Nutritionists widely agree that natural protein sources—including seeds, nuts, eggs and yoghurt—are superior for bodily health. Yet, they acknowledge that not all protein bars are created equal; some formulations are markedly more nutritious than others.
Evaluating the Best and Worst Options
Ms Campbell has provided her expert verdict on specific protein bars available in UK supermarkets, identifying both the healthier choices and those best avoided.
The Healthier Selections
Fulfil Chocolate Salted Caramel Vitamin & Protein Bar (£2.90 for 55g at tesco.com). Experts regard this as one of the healthier options, being low in sugar and high in protein. Its unique selling point is enrichment with nine vitamins, including folic acid, vitamins E and C, and four B vitamins. At 204 calories and 20g of protein, it is energy-dense but nutritionally substantial, with just 1.7g of sugar. Campbell notes its relatively low fibre (3.4g) and that its sweetness derives from sugar alcohols, a processed ingredient.
Fast 800 Dark Chocolate Raspberry Protein Bar (£26.99 for 12 x 45g bars at thefast800.com). This bar offers 14g of protein and 9g of fibre, primarily from peanut paste and chicory root fibre. It contains a minimal 1g of sugar and 192 calories. However, Campbell points out it contains added sweeteners and soya protein isolate, a refined ingredient.
The Protein Ball Co Blueberry Oat Muffin (£1.85 for 45g bag at healthysupplies.co.uk). Made primarily with natural ingredients like dates, almonds and freeze-dried blueberries, these balls are lower in protein (6.5g) but avoid ultra-processing. Their 17g of sugar comes naturally from dates, which also provide nutrients like potassium.
Deliciously Ella Roasted Peanut Protein Ball (£1.90 for 40g ball at Waitrose.com). Another natural option with dates, peanuts and peanut butter as main ingredients. It is low in calories (150) and fat (5.2g), though protein content is modest at 4.6g. The 16g of sugar is natural.
Pip & Nut Dark Chocolate Peanut Protein Bar (£4 for 3 x 46g bars at tesco.com). This bar provides 10g of protein and 10g of sugar, with peanuts and dark chocolate as key ingredients. It is higher in calories (217) and fat (12g), and uses agave syrup, which is more refined than often perceived.
The Unhealthiest Choices
Trek Power Lotus Biscoff Bar (£2.29 for 55g bar at proteinpackage.co.uk). This bar is alarmingly high in calories (239), sugar (8.9g) and fat (12g), with much fat from artificial sources. While it offers 15g of protein and 8.6g of fibre, Campbell warns it is packed with ultra-processed ingredients like candied sugar syrups and refined vegetable oils.
Grenade Oreo White Protein Bar (£2.70 for 60g bar at tesco.com). Despite being a market leader and low in sugar (0.7g) and calories (135), this bar contains minimal fibre (0.5g) and only 12g of protein. Campbell criticises its reliance on artificial sweeteners like sucralose, along with flavourings and refined oils, categorising it as highly ultra-processed.
The overarching message from UK nutritionists is clear: while the protein bar market continues to expand, consumers must scrutinise labels carefully. Opting for bars with recognisable, whole-food ingredients and minimising consumption of those laden with ultra-processed components is crucial for maintaining long-term health.
