Why Is Joe Wicks Selling Britain’s Most Dangerous Protein Bar?

Picking up a protein bar in the supermarket might feel like a healthy choice. It contains 20g of protein – how bad can it be? Gains are gains, right? Wrong, if Joe Wicks’ new documentary is anything to go by. Channel 4’s Joe Wicks: Licensed To Kill follows the fitness guru as he creates a fake protein bar that’s packed with harmful additives in cahoots with Dr Chris van Tulleken – a bid to highlight the dangers of ultra-processed foods (UPFs).

Joe Wicks: Licensed To Kill, Explained

This eye-opening new documentary sees Wicks and van Tulleken joining forces on a provocative stunt, manufactured with the hopes of lobbying the government to change food laws. In the UK, UPFs make up 53 percent of total calorie intake, according to a survey from 2025, and this over-consumption is having detrimental effects on our health. A study published in the British Medical Journal linked UPFs with a higher risk of 23 health problems, including cancer and cardiovascular disease, contributing to 14 percent of premature deaths.

Part of the problem is the confusion surrounding the topic. These synthesised ingredients which are so often added into our food (emulsifiers, sweeteners, hydrogenated fats and oils) are legal, and marketing laws remain hazy, meaning it can be hard to decipher whether a product is classified as a UPF or not. 

Chris van Tulleken (c) BBC/Lion Television/Tom Barnes

Wicks’ stunt aims to expose the truth. The documentary shows the fitness coach creating an ultra-processed protein bar called ‘Killer’ in order to ‘show the harms of a UPF-heavy diet and how the industry misleads consumers’. He enlisted one of the world’s top UPF experts, van Tulleken, to help. The British doctor published a landmark book on the topic in 2023, Ultra Processed People, and he has since created a number of documentaries including Irresistible – Why We Can’t Stop Eating, which explores the lengths food companies go to to make their products so addictive.

‘My Killer bar is high in saturated fat and sugar, and made up of 96 ingredients, some of which are linked to cancer, stroke, even early death,’ says Wicks. ‘Sweetener sucralose may damage the gut lining; glycerol has been linked to a spate of hospitalisations in young children; maltitol may cause diarrhoea when consumed in large doses; and aspartame has been labelled a Group 2B or “possibly carcinogenic” agent by the World Health Organisation, meaning it might cause cancer.’

Many of these ingredients are commonly found in protein bars, but for the show Wicks increased the quantity, while keeping them within legal limitations. The craziest part? Killer can still be labelled as ‘healthy’, simply because it contains flax seeds and vitamins. 

The hope is that the government will bring in new mandatory warnings on UPF food packaging – a move which has had a positive impact in Chile since being brought in back in 2016. ‘I really believe we shouldn’t accept this as the norm and carry on as we are,’ says Wicks. ‘We deserve a chance to eat better.’

 

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A post shared by Joe Wicks (@thebodycoach)

After years of running bootcamp sessions, Wicks garnered a cult following under his alias The Body Coach, known initially for his 15-second #Leanin15 recipes. He soon published a cookbook (the first of many) and began sharing workouts on his YouTube channel, eventually creating a personalised fitness programme called the 90 Day Plan. Over the years, Wicks has also starred in a number of TV shows including Saturday Kitchen and This Morning, as well as being a guest judge on the latest series of Dragon’s Den.

Van Tulleken, meanwhile, studied medicine at Oxford University before rising to fame with children’s series Operation Ouch!, which he hosted with his twin brother Dr Xand. The duo went on to front a number of shows focusing on health and nutrition, and recently launched a podcast for BBC Radio 4, What’s Up Docs?. 

When Does Joe Wicks: Licensed To Kill Come Out?

The documentary will air on Channel 4 at 8pm on 6 October 2025.