High-protein snacks under scrutiny as UK study finds most exceed NHS sugar guidelines

Protein snacks sold in UK supermarkets may not be delivering the nutritional benefits consumers expect, according to new research from Oxford Online Pharmacy, which found that nearly 90% of products analyzed exceeded NHS recommendations for sugar intake while some carried significantly higher costs per gram of protein than others.

• Researchers analyzed 88 high-protein snacks sold across the UK’s six largest supermarkets, including yogurts, milkshakes, bars, coffees, and porridge pots.
• Protein yogurts provided the lowest cost per gram of protein, while protein bars were found to be the least cost-effective category.
• Nearly 90% of products exceeded NHS guidance on free sugar intake, and more than a quarter failed to meet protein thresholds recommended for GLP-1 users.

The findings came as protein continued to dominate health and wellness marketing, with the category attracting growing attention from consumers seeking convenient nutrition products and from users of GLP-1 weight-loss medications who are encouraged to maintain higher protein intakes to preserve muscle mass during calorie restriction.

Oxford Online Pharmacy noted that the UK protein market was expected to reach £631 million (US$855 million) by 2031, creating strong incentives for manufacturers to expand their high-protein offerings across supermarket shelves.

The study examined 88 products available in the UK’s six largest supermarket chains, including both branded and private-label items. Researchers assessed protein content, cost, sugar levels, and nutritional profiles across categories including yogurts, milkshakes, porridge pots, protein bars, and coffee drinks.

Central to the analysis was the concept of 'protein-washing', which researchers described as a marketing practice whereby products are promoted using claims such as “high-protein” or “protein-packed,” potentially creating a health-focused perception that may not reflect the overall nutritional quality of the product.

According to the report, online searches for the term “protein-washing” increased by more than 486% over the past year, reflecting growing consumer interest in whether protein claims justify premium pricing.

When researchers evaluated value for money, protein yogurts emerged as the most cost-effective option. The average product contained 20g of protein and cost £1.29 (US$1.75), equating to approximately 7p per gram of protein.

Protein milkshakes ranked second, delivering an average of 26.3g of protein at roughly 8p per gram.

At the opposite end of the scale were protein bars. While the average bar contained 18g of protein, it cost £1.98 (US$2.68), equivalent to around 12p per gram of protein.

Robert Bradshaw, Superintendent Pharmacist at Oxford Online Pharmacy, said consumers needed to pay closer attention to the actual nutritional and economic value offered by protein products.

“Many consumers buy high-protein snacks as a budget option that still delivers nutritional benefits, but some products cost nearly double per gram of protein compared to others,” said Bradshaw. “For those already managing rising food and private GLP-1 mediation costs, choosing good value protein sources is key.”

The study also raised concerns about sugar content across the category.

Researchers found that 16% of products contained equal or greater amounts of sugar than protein, including six protein yogurts. While yogurts delivered the strongest value on a protein-per-pound basis, the report suggested consumers should evaluate broader nutritional content rather than focusing solely on protein claims.

Among the 88 products analyzed, 77 exceeded NHS recommendations that no more than 5% of daily calories should come from free sugars.

Protein milkshakes were identified as the category with the highest average sugar contribution, with 33% of calories derived from sugar. Two products contained more than an adult’s recommended daily sugar intake in a single serving, with nearly half of their calories coming from sugar.

Protein coffee drinks followed closely behind, with 32% of calories derived from sugar on average. Protein yogurts ranked third at 26%.

Protein bars performed better on sugar content, with only 7% of calories coming from sugar on average. However, researchers noted that many products relied on alternative sweeteners such as sucralose, acesulfame K, maltitol, sorbitol, erythritol, and stevia to enhance flavor.

The report stated that while such sweeteners were not inherently dangerous, studies had linked some of them to issues including gastrointestinal discomfort, altered glucose metabolism, and changes to the gut microbiome.

Bradshaw warned that consumers should not assume a protein claim automatically signaled a healthy product.

“Consumers should be aware that a snack labelled as high-protein is not automatically healthy,” he said. “This is where ‘protein-washing’ can become a problem, as people think they’re eating a healthy diet but could be, unbeknownst to them, consuming large quantities of sugar alongside protein.”

He added: “My advice is to only eat on-the-go protein snacks infrequently and in small quantities. They shouldn’t be relied on as primary protein sources. Naturally protein-rich whole foods like grilled chicken breast, canned tuna, nuts and seeds, edamame beans, boiled eggs, cottage cheese and plain Greek yoghurt are all foods that can be added to meals and bought as snacks to increase intake while prioritising nutrition and limiting sugar.”

The study also examined how well products aligned with the needs of GLP-1 users, a rapidly growing consumer group encouraged to consume higher levels of protein while maintaining a calorie deficit.

Researchers used a threshold of at least 30% of calories coming from protein, a level often recommended for people taking GLP-1 medications to help reduce the risk of muscle loss during weight reduction.

More than a quarter of products analyzed failed to meet that benchmark.

Protein porridge products performed worst, with 15 of the 16 products studied falling below the 30% threshold. By contrast, all 18 protein yogurts exceeded it, with some deriving as much as 68% of calories from protein.

Bradshaw said the findings suggested some products marketed toward protein-conscious consumers were not necessarily meeting the needs of people actively seeking higher protein diets.

“It’s concerning to see how many snacks aren’t delivering the protein and nutrition they’re branding suggests,” said Bradshaw. “Depending on your weight, you should consume upwards of 66g of protein per day, and when you’re trying to keep yourself in a calorie deficit, a potentially lower protein but higher calorie and sugar-filled snack could make it harder to stay on track.”