If you grab a protein bar or shake after a workout, believing it's a healthy choice, you may be inadvertently sabotaging your fitness goals. A stark new investigation has uncovered that the vast majority of protein products sold in UK shops are ultra-processed and packed with excessive sugar, salt, and fat, despite their health-focused marketing.
The Grim Reality of the Health Food Aisle
Researchers from the online doctor service ZAVA conducted a detailed analysis of 55 popular protein items, including drinks, bars, breads, yoghurts, and savoury snacks. The findings present a troubling picture of the sector.
The study classified a staggering 94% of the tested products (52 out of 55) as ultra-processed, falling into the NOVA 4 category. This system, developed by Brazilian public health experts, groups foods by their level of industrial processing. Furthermore, one in four of these so-called 'health' products was found to be unhealthy due to high levels of sugar, fat, or sodium.
Hidden Dangers in Plain Sight
The analysis pinpointed several critical issues with these popular fitness snacks:
- Hidden Sugar: Protein drinks contained an average of 19.3g of sugar per serving – nearly matching the sugar content in a standard can of Coca-Cola.
- High Fat Content: Protein bars derived an average of 40.5% of their calories from fat. Alarmingly, some bars were found to contain more sugar than protein.
- Salt Traps: Savoury 'deli-style' protein snacks were particularly high in sodium. One single beef stick contained more salt than a typical fast-food burger.
Why Ultra-Processed Foods Undermine Health Goals
This revelation is especially significant for individuals focused on weight management. While these products deliver protein, their chemical composition can hinder fat loss. This is critically important for people using appetite-suppressing GLP-1 medications like Wegovy or Mounjaro.
A 2025 clinical trial published in Nature Medicine demonstrated that people on a minimally processed diet lost twice as much fat as those eating ultra-processed foods, even when total calories were the same. Ultra-processed foods (UPFs) are linked to reduced feelings of fullness, increased cravings, and issues like digestive problems and fatigue.
Dr Crystal Wyllie of ZAVA highlighted this 'nutritional disconnect'. "Almost all protein products on supermarket shelves are ultra-processed," she explained. "They may hit a protein target, but they quietly compromise on sugar, salt or fat."
She issued a specific warning for those on medical weight loss plans: "With appetite suppressed, every bite counts. Ultra-processed proteins are calorie-dense, eaten faster, and don’t provide lasting fullness. That means patients may waste their reduced intake on foods that don’t support long-term success."
Choosing Smarter Protein Sources
The report stresses that protein remains essential, but its source is paramount. While savoury snacks and drinks offered the highest raw protein numbers (around 27g per serving), they came with a heavy trade-off in salt and sugar.
The study identified protein yoghurts and protein breads as more balanced choices, providing moderate calories and lower sugar levels compared to bars and shakes.
Ultimately, Dr Wyllie advises consumers to return to basics to avoid the hidden pitfalls of processing. "The key takeaway is not to avoid protein, but to choose smarter protein," she said. "Whole food sources - eggs, Greek yoghurt, chicken, fish, or legumes - deliver lasting satiety and support the body’s natural hunger regulation."
This research emerges as fitness expert Joe Wicks prepares to release a documentary exposing what he terms the UK's 'most deadly' protein bar, signalling a growing scrutiny of the fitness food industry.
