Why your ‘healthy’ snacks may be sabotaging your weight loss

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Wellbeing

Over the past few years, we’ve become obsessed with increasing the amount of protein in our diets, often turning to protein powders and foods marketing as high protein in order to reach our goals.

However, despite being marketed as healthy, most protein products on UK shelves are ultra-processed, high in sugar, salt, or fat, and may even undermine weight loss efforts, especially for patients using appetite-suppressing medications.

The study, conducted by ZAVA, comes as health guru Joe Wicks prepares to release his new documentary, highlighting the UK’s most deadly protein bar, a product packed with ultra-processed ingredients linked to one in six premature deaths nationwide.

ZAVA’s team examined 55 popular protein products across five categories: drinks, bars, breads, yoghurts, and high-protein savoury snacks. Nutritional content and NOVA processing scores were assessed, revealing alarming trends.

Here are their key findings:

  • 94% of protein products (52 out of 55) were classified as ultra-processed (NOVA 4)
  • 1 in 4 protein-labelled products were found to be unhealthy, due to high levels of sugar, fat, or sodium
  • Protein drinks averaged 19.3g of sugar per serving, nearly as much as a can of Coca-Cola
  • Protein bars contained, on average, 40.5% of their calories from fat, with some containing more sugar than protein
  • Protein deli snacks were protein-rich but extremely salty; one beef stick contained more sodium than a fast-food burger

The nutritional breakdown of high-protein foods

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Protein powerhouses:

  • High-protein savoury snacks lead the pack with an impressive 27.6 g of protein per serving, making them ideal for those chasing maximum protein with minimal carbs.
  • Protein drinks aren’t far behind, delivering 27.9 g of protein, but also come with higher sugar and calorie content, perfect for post-workout refuelling.

Balanced choices:

  • Yoghurts and protein breads strike a nice balance, offering moderate calories and protein with lower sugar levels, making them great everyday options.

Hidden considerations:

  • While protein is a major selling point, sodium levels are high in certain items, particularly savoury snacks (898 mg per serving) and protein breads (575 mg), which could be a concern for those watching their salt intake.

Ultra-processed factor: 

  • Most high-protein products are highly processed (NOVA scores 3.8–4), with protein bars standing out as the most processed option.

Why it matters: The hidden weight loss impact

While these foods hit protein targets, their high levels of sugar, fat and salt may undermine weight loss, particularly for patients using GLP-1 medications such as Wegovy or Mounjaro.

A recent clinical trial published in Nature Medicine (2025) showed that people following a minimally processed diet lost double the fat compared to those consuming ultra-processed alternatives, despite both diets meeting healthy eating guidelines.

The trial also found that ultra-processed foods reduced satiety, worsened cravings, and were linked to higher reports of reflux, fatigue, and digestive issues.

Choose smarter protein

According to Dr Crystal Wyllie at ZAVA the analysis shows a troubling disconnect between consumer expectations and nutritional reality. Almost all protein products on supermarket shelves are ultra-processed. They may hit a protein target, but they quietly compromise on sugar, salt or fat.

This is especially important for patients on weight loss treatments like Wegovy. With appetite suppressed, every bite counts, and 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.

The key takeaway is not to avoid protein, but to choose smarter protein. Whole food sources, eggs, Greek yoghurt, chicken, fish, or legumes, deliver lasting satiety and support the body’s natural hunger regulation, without the hidden pitfalls of ultra-processing.