Honestly, if you've turned on a TV or walked through a bookstore in the last few years, you’ve seen him. The tall, energetic doctor with the slightly messy hair and an identical twin who looks just like him. Dr Chris van Tulleken has become the face of a massive shift in how we think about what we put in our mouths.
But there is a lot of noise. People think he’s just another "diet doctor" telling us to eat kale and run marathons. He isn't. In fact, he’s kind of the opposite.
The Myth of the "Healthy" Diet
Most people think Chris van Tulleken is out here trying to give us a meal plan. If you pick up his 2023 bestseller, Ultra-Processed People, looking for recipes, you’re going to be disappointed. There aren't any.
His whole point—and this is where people get him wrong—is that it isn't about your willpower. It's not about you being "lazy" or "weak."
Basically, he argues that our food environment is rigged. We are living in a world where 60% of the average diet in the UK and USA comes from substances that aren't really "food" in the traditional sense. They are industrially produced formulations.
He calls it Ultra-Processed Food (UPF).
Why Chris van Tulleken Changed the Conversation
Before he was the "UPF guy," Chris was (and still is) a serious academic. We’re talking an infectious diseases doctor at University College London Hospitals with a PhD in molecular virology. He’s spent years working in humanitarian emergencies in places like the Central African Republic and Myanmar.
He didn't just wake up and decide to hate on Pringles.
What changed things was a self-experiment he did for the BBC documentary What Are We Feeding Our Kids?. Under medical supervision at UCL, he ate a diet of 80% UPF for a month.
The results were sort of terrifying:
- He gained 6kg (about 13 lbs) in just 30 days.
- He developed piles, constipation, and anxiety.
- Brain scans showed his neural pathways had actually rewired.
- His brain started reacting to UPF the way an addict’s brain reacts to drugs.
It wasn't just that he was eating "junk." He was eating stuff designed by scientists to bypass the signals that tell your brain "I'm full."
It Isn't Just About Sugar or Fat
This is the big H2 moment: Dr Chris van Tulleken is arguing something much more radical than "sugar is bad."
A lot of critics, like Christopher Snowdon from The Critic, have pointed out that most UPF is also high in salt, sugar, and fat. So, is it the processing or just the ingredients? Chris argues it’s the processing itself.
Think about an apple. You chew it. It has fiber. Your body takes time to break it down. Now think about a "healthy" protein bar filled with emulsifiers, sweeteners, and soy protein isolate. Even if the calories are the same, your body treats them differently.
The emulsifiers in that bar might be messing with your gut microbiome—the "dietary rainforest" in your belly. In 2025 and 2026, research has continued to back this up. A major study published in Nature Medicine in August 2025, which Chris co-authored, showed that people cooking from scratch lost twice as much weight as those eating UPF, even when the nutrients were supposedly "matched."
The Twin Factor: Chris and Xand
You can't talk about Chris without mentioning Xand (Alexander). They are identical twins—literally "clones," as Chris jokes.
This gives them a unique edge in science. They can do "test and control" experiments on themselves. While they are famous for Operation Ouch! on CBBC, where they do gross-out experiments for kids, their adult work is pretty sober.
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In late 2025, Chris even had to clarify his stance on "perfection." He told Runner's World that he actually eats UPF on Christmas Day. "I’m not going to kill myself doing everything from scratch," he said. It’s a refreshing take. He’s not a monk; he’s a guy trying to highlight a systemic problem.
What Most People Miss About His Research
People think he’s attacking the food. He’s actually attacking the corporations.
His recent lectures, including the 2024 Royal Institution Christmas Lectures and his 2025 work as an editor for the Future Healthcare Journal, focus on "commercial determinants of health."
He’s looking at how big companies (Big Food) influence policy. He’s worked with UNICEF and the WHO to show how formula milk marketing can undermine breastfeeding. He’s not just telling you to stop eating nuggets; he’s telling the government to stop letting companies market those nuggets to your toddlers.
Fast Facts on Chris van Tulleken
- Born: 18 August 1978 in London.
- Education: Oxford University (Medicine), UCL (PhD).
- Family: Married to Dinah; they have two daughters.
- Title: Professor of Infection and Global Health at UCL.
- Nobility: He actually holds the Dutch rank of Jonkheer, though he never uses it.
The 2026 Perspective: Where We Are Now
As of early 2026, the UK government is finally moving on some of this. There are new restrictions on TV and online advertising for "less healthy" foods.
But it’s a battle.
Chris has been vocal about the fact that "reformulation" (making a Snickers bar slightly less salty) isn't the answer if it’s still a highly processed industrial product. He wants stop-sign labels on packaging, similar to what they use in Chile and Peru.
Actionable Steps: What You Can Actually Do
If you're feeling overwhelmed by the idea that your pantry is a "minefield," here is the expert-backed way to handle it based on Chris's work:
- The Kitchen Test: Look at the ingredients. If there is even one thing you wouldn't find in a normal home kitchen (like xanthan gum, soy lecithin, or "high-fructose corn syrup"), it’s UPF.
- Don't Stress Perfection: Even Chris eats the stuff occasionally. The goal is to reduce the percentage of your diet that comes from a factory.
- Watch the "Healthy" Labels: Be wary of anything with a "high protein" or "low fat" claim. These are often the most processed items on the shelf.
- Advocate: Support policies that restrict marketing to children. This is the "big picture" goal Chris is pushing for.
Dr Chris van Tulleken has shifted the blame from the individual to the system. It’s a message that resonates because, deep down, most of us know that eating a "fruit" snack that has never seen a tree feels a bit wrong. His work provides the hard science to prove why that intuition is right.