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Will Wicks’ Killer Bar harm the protein bar category?

Joe Wicks’ deliberately dangerous protein bar is fuelling anti-UPF sentiment – but there are concerns that his messaging is misguided and could have unintended consequences.

In October, a new nutrition bar was launched in the UK. However, the Killer Bar is no ordinary snack, but a stunt by health and fitness influencer Joe Wicks.

His aim, he said, was to draw attention to the “harmful” ingredients that are in many ultra-processed foods (UPFs) and to convince the government to change labelling regulations so that foods containing these ingredients are forced to carry warnings.

“The bar is for sale – it’s not to be eaten; it’s a vehicle for a campaign; to get the government to change and put legislation in place to help us eat better and give us honest, transparent, truthful information about the foods we are eating,” Wicks wrote in an Instagram post.

The Killer Bar is high in both protein and fibre, and fortified with vitamins and minerals, allowing it to make corresponding health and nutrition claims. But it also carries an on-pack warning that "excessive consumption may increase your risk of cancer, stroke, and early death”.

Some of the 96 ingredients that have been called out for potential health risks include aspartame, maltitol, maltodextrin, glycerol, hydrolysed protein, and stabilisers and emulsifiers such as lecithin, polydextrose, and polyglycerol polyricinoleate.

Killer Bar: Mixed reactions

In a one-off Channel 4 documentary aired in October, Wicks and Ultra-Processed People author Professor Chris van Tulleken told the story behind the campaign and exposed the alleged dangers of UPFs.

The campaign has elicited both positive and negative reactions, getting everyone from consumers to protein bar brands, academics, and marketers talking about UPFs.

One of the criticisms is that the science on which the campaign is based – namely that UPFs and certain industrial ingredients pose a risk to human health – is shaky.

As yet, there is no universally agreed definition of what a UPF is, and of what foods fall into this classification.

What’s more, although research consistently shows a strong association between a high intake of UPFs and poor health outcomes, direct causation has yet to be established.

Campaign under fire

Dietitian Dr Carrie Ruxton told Ingredients Network: “I’m not supportive of the campaign as it is jumping the gun and promoting a concept for which there is still no consensus in the academic community or at government level.

“All of the evidence for disease associations is based on observational studies and the authors of these have retrofitted the NOVA classification to the data. So, it remains unproven that foods from a particular NOVA category are to blame for increased risk of chronic diseases – it could easily be high intakes of sugar, saturated fat or salt, or low intakes of fibre, fruit, vegetables, vitamins, minerals, or polyphenols.”

Ruxton’s advice is that consumers ignore the noise around UPFs and focus on energy density (calories per serving) and the fibre, salt, and sugar content of foods, as this is where the strongest evidence lies. Consumers should also boost their intake of plant foods – aiming for five fruit and vegetables a day – as well as cook more at home and choose lean proteins, she added.

“These simple guidelines are likely to be more effective than creating unnecessary worry about processing. It’s worth remembering that the UPF category contains packaged wholemeal bread, cooking sauces in jars, low-fat yoghurts, infant formula milk, plant milks, meat/egg alternatives, high-fibre breakfast cereals, and some tinned vegetables,” she said.

“These are all healthy foods and useful for the time-pressed consumer. There is absolutely no need to avoid them.”

Consumers shun processed bars

However, it seems that the negative press around UPFs is starting to influence consumer buying habits.

According to Mintel's UK Snack Bars and Breakfast Biscuits Market Report 2025, 51% of consumers reported eating fewer cereal and snack bars in the past three months due to concerns about these products being overly processed.

Mintel said this trend is especially evident among younger, more engaged demographics and frequent consumers of these bars (57%), impacting consumption habits and potentially eroding the category's core consumer base.

Ruxton predicted that the Killer Bar campaign will probably harm perceptions but said that her concerns were more around what happens next.

“Will consumers stop eating processed snacks and choose fresh fruit instead?” she asked. “I think this is unlikely, as fear-based campaigning can often lead to unintended consequences such as people eating more ‘natural’ chocolate or ‘additive-free’ sugar confectionery, or baking cakes at home. This would not improve the nutritional quality of their diets.”