On killer bars and communication breakdown

Joe Wicks and Christian van Tulleken have been making headlines again - this time not for burpees or baby sleep schedules, but for a protein bar. Their new “Killer” bar isn’t just another snack promising high protein and low guilt. It’s a statement. Designed to highlight the supposed dangers and regulatory failings around ultra-processed foods (UPFs), it’s part stunt, part social commentary.

The bar comes wrapped in irony - literally - with marketing that reads like a warning label. And while some have applauded the move for starting a conversation about our over-reliance on convenience foods, others have accused the pair of alarmism and scientific oversimplification. Critics range from social media trainers to academics like Tim Spector and the Zoe team, who’ve taken issue with what they see as fear-mongering and cherry-picking of evidence.

So who’s right?

The science and the signal

Let’s start here: the UPF debate isn’t new. The NOVA classification, which lumps foods into categories from “minimally processed” to “ultra-processed”, was originally intended for population-level research, not for individuals trying to navigate their weekly shop.

What we do know is that diets high in UPFs tend to be higher in calories, lower in fibre, and associated with poorer health outcomes. But correlation doesn’t equal causation. People who eat more UPFs also tend to have other lifestyle factors that influence their health - lower income, less access to fresh foods, higher stress levels. The “why” matters as much as the “what”.

And not all UPFs are equal. Yoghurt with added fruit purée, fortified breakfast cereals, or plant-based milks might technically count as ultra-processed, but they can still contribute valuable nutrients. The “Killer” bar itself, ironically, sits in that same grey area - a manufactured blend of protein, sweetener, and emulsifiers.

When the message becomes the problem

The interesting thing about this debate isn’t the science - it’s the storytelling. Nutrition has a communication problem.

It’s hard to get people to care about nuanced data. It’s much easier to get them to react to fear, guilt, or hope. “This food kills” or “this one saves you” grabs attention in a way that “context matters” never will. But once the conversation is framed in absolutes, moderation becomes invisible.

For every nutritionist urging calm and perspective, there’s an influencer posting a reel about “food freedom” or “toxic ingredients”. Somewhere between the panic and the dismissal, the actual evidence gets lost. And so do the people trying to make sense of it all.

The real-world consequences

So what happens if you follow the wrong advice? To be honest, not much - at least not immediately. You might waste money on supplements or avoid foods that could actually help you meet your nutrient needs. You might end up with a bit more anxiety around eating than you started with.

But over time, that’s the real harm: the erosion of trust. When public figures argue in extremes, people stop believing any of them. They disengage completely - deciding nutrition is too confusing to bother with - and the opportunity for real, sustainable change slips away.

Finding the middle ground

The truth, predictably, lives somewhere in the middle.

Yes, we should be mindful of how much ultra-processed food we eat. Home-cooked meals built around whole ingredients will usually be better for health, satiety, and energy. But it’s also true that convenience foods make modern life possible - and demonising them helps no one.

If there’s one thing worth taking from the “Killer” controversy, it’s this: the same way the dose makes the poison, the tone makes the message. The louder and more dramatic the claims, the less useful they tend to be.

Nutrition doesn’t need more heroes or villains. It needs more honesty - and a lot more moderation, not just on our plates but in our conversations too.

If you want help navigating nuances in your nutrition, let's chat.