The “Killer Bar” Debate: What We Really Need to Know About Ultra-Processed Foods

Joe Wicks’ Killer Bar campaign reignited debate around ultra-processed foods (UPFs). Discover what the science really says, why demonising all UPFs is unhelpful, and how to find a balanced, practical approach to healthy eating.

When a “Killer Bar” causes confusion

When fitness influencer Joe Wicks launched a “Killer Bar” to make a point about ultra-processed foods, it certainly sparked conversation. His goal was to highlight how heavily we rely on industrially made foods — but calling them “killers” sent an extreme and misleading message.

The truth is, ultra-processed foods are not all created equal. Some are best kept for occasional enjoyment, while others can be useful, affordable and even nutritious. Blanket fearmongering isn’t the answer — and it risks fuelling guilt and disordered eating patterns.

How much of our diet is ultra-processed?

In the UK, ultra-processed foods now make up around 65% of the calories we eat — one of the highest proportions in Europe. From breakfast cereals and crisps to ready meals and snack bars, they’re an everyday part of life. But research shows that when they make up too much of our diet, we tend to eat more overall and gain weight more easily.

What actually counts as “ultra-processed”?

The term comes from the NOVA food classification system, which groups foods by how much they’ve been altered:

• Unprocessed or minimally processed foods: fresh fruit, vegetables, whole grains, pulses, eggs, nuts, plain meat or fish.

• Processed foods: items like cheese, tinned vegetables or bread that have been slightly altered for taste or preservation.

• Ultra-processed foods (UPFs): industrially formulated products made mostly from refined ingredients such as starches, sugars and oils, plus added colours, flavourings, sweeteners or emulsifiers.

In short, UPFs are products that bear little resemblance to the whole foods they came from.

Why we tend to eat more when foods are ultra-processed

In a controlled study, people were offered two different diets — one based on unprocessed foods and the other on ultra-processed foods. Both had the same amount of calories, fat, sugar and protein. Participants could eat as much or as little as they liked.

When eating the ultra-processed meals, they consumed around 500 extra calories per day and gained weight. On the unprocessed diet, they naturally ate less and lost weight.

Researchers believe this happens because UPFs are:

• Easier and quicker to eat, giving our bodies less time to register fullness.

• “Hyper-palatable”, with combinations of fat, salt and sugar that make them irresistible.

• Calorie-dense but less filling, meaning we take in more energy without feeling satisfied.

This helps explain why it’s so easy to polish off a packet of crisps or biscuits before we even notice.

Are additives harmful?

Many UPFs contain additives such as emulsifiers, sweeteners and preservatives. These are considered safe by food authorities, but new research is exploring whether long-term exposure could affect gut health in subtle ways.

Animal studies suggest some emulsifiers might disrupt the balance of gut bacteria and increase inflammation. Human studies are still emerging, so there’s no cause for alarm — but it does reinforce the value of eating a wide variety of foods, and not relying too heavily on heavily processed ones.

Not all UPFs are bad news

It’s too simplistic to say that all ultra-processed foods are unhealthy. The category is broad — and some options can play a positive role in a balanced diet.

Examples include:

• Tinned baked beans (reduced salt and sugar): a source of plant protein and fibre.

• Houmous: whether homemade or shop-bought, it provides healthy fats, protein and fibre.

• Fortified foods: such as certain breakfast cereals or plant milks, which help fill nutrient gaps.

The key is to look at what’s inside rather than how much it’s been processed. A balanced diet can absolutely include some UPFs, especially those that make nutritious eating more achievable.

The affordability gap and food inequality

While it’s easy to say “just cook from scratch,” the reality is that not everyone can. Fresh foods can be more expensive and spoil faster, while UPFs are often cheaper, quicker, and have a longer shelf life.

People on lower incomes or with limited time, energy or kitchen facilities may rely more on processed foods simply out of necessity. This is not a lack of willpower — it’s a reflection of social and economic inequality.

Public health efforts should therefore focus on making whole foods more affordable and accessible, not shaming those who depend on convenient options.

Why demonising UPFs does more harm than good

The Killer Bar campaign may have been attention-grabbing, but the idea that any single food is “toxic” or “deadly” is deeply misleading. It’s also counterproductive. When we label foods as “good” or “bad,” it can lead to guilt and anxiety — and for some, trigger disordered eating behaviours.

Food is not moral. A chocolate bar doesn’t make you a bad person any more than a salad makes you virtuous. Most people eat a mix of foods, and that’s perfectly normal. What matters most is your overall diet — not the occasional processed snack.

How to take a balanced, realistic approach

Rather than fearing UPFs, focus on small, sustainable changes that improve overall diet quality:

1. Base meals on whole or minimally processed foods where possible — vegetables, fruits, pulses, nuts, seeds, and whole grains.

2. Keep practical UPFs that support a balanced diet, like tinned beans, houmous and fortified cereals.

3. Cut back gradually on less healthy UPFs such as fizzy drinks, crisps and confectionery.

4. Avoid food guilt. Perfection isn’t the goal — progress is.

5. Plan ahead when possible. Batch cooking or freezing leftovers can help reduce reliance on convenience foods.

Remember, it’s about balance, not restriction.

A compassionate way forward

Ultra-processed foods are part of modern life, and for many people, they make healthy eating possible. The goal isn’t to eliminate them entirely but to reduce the least nutritious types when we can — and to build more meals around foods closer to their natural form.

Instead of scare tactics, we need practical advice, empathy, and systemic change:

• Helping people make small, realistic improvements based on their circumstances.

• Advocating for fair food prices and access to affordable produce.

• Encouraging balance rather than shame.

Food should nourish both body and mind. Let’s move beyond fearmongering headlines and help people make informed, confident, and guilt-free choices.