Laura: I looked at my pantry after reading this book and had a full-blown identity crisis. It turns out that over 60% of the average diet in the UK and US isn't food. It's something else entirely. Sophia: Whoa, hold on. What do you mean ‘not food’? Like, my breakfast cereal isn't food? My bread isn't food? That sounds a little dramatic. Laura: It does, but that feeling is exactly what Dr. Chris van Tulleken captures in his book, Ultra-Processed People: The Science Behind Food That Isn’t Food. Sophia: And he's not just a journalist, right? He's an infectious disease doctor and an associate professor at UCL. He actually ran a self-experiment, eating 80% UPF for a month, which got a ton of attention. Laura: Exactly. He brings this unique blend of scientific rigor and being his own guinea pig. The book became a huge bestseller and was even longlisted for the Baillie Gifford Prize, so it clearly struck a nerve. It all starts with a simple, almost funny story from the book: his daughter's ice cream that wouldn't melt. Sophia: Okay, now I'm listening. An unmelting ice cream? That’s the beginning of a horror movie.

Laura: It really is. He describes being at the park on a warm day. His three-year-old daughter, Lyra, has a scoop of pistachio ice cream. She gets distracted, leaves it in the sun, and when he goes to clean it up, it’s barely changed. It’s just a warm, gelatinous foam. Sophia: That’s so weird. What was in it? Laura: When he looked up the ingredients, it wasn't just cream and sugar. It was a long list of things like stabilizers, emulsifiers, gums, lecithin, glucose syrups… things you definitely don't have in your kitchen. This is the heart of his argument. He gives a simple rule of thumb: if it’s wrapped in plastic and has at least one ingredient you wouldn’t find in a standard home kitchen, it’s Ultra-Processed Food, or UPF. Sophia: Okay, but that just sounds like processed food. Is 'ultra-processed' just a scarier-sounding name for a bag of chips or a frozen pizza? What’s actually new here? Laura: That’s the key question. The book argues it’s a completely different category. Regular processed food is something like canned tomatoes or cheese—foods that are modified. Ultra-processed food is something else. It’s food that’s been broken down into its basic molecular constituents—protein isolates, starches, fats—and then reassembled into new forms with additives. Sophia: So it’s like food Legos? They take apart the original thing and build something new? Laura: A perfect analogy. And the purpose of that reassembly is crucial. It’s not to nourish you; it’s to create a product that is incredibly cheap to make, has a super long shelf life, and is engineered to be hyper-palatable, so you eat more of it. The book traces this logic to its most extreme conclusion with the story of 'coal butter' in Nazi Germany. Sophia: Coal butter? You’re kidding. Laura: Not at all. During WWII, a German chemist named Arthur Imhausen figured out how to synthetically create an edible fat from coal byproducts. It was the ultimate UPF—an 'edible substance' made from something that was never food to begin with. The book uses this to show how far the industrial logic can go. Sophia: That’s horrifying. And it makes the unmelting ice cream seem a lot less innocent. It’s not just a quirk; it’s a sign that the substance is following a different set of rules. Laura: Exactly. It’s not behaving like food because, in a very real sense, it isn't.

Sophia: Okay, so it's a different category of substance. But how does it actually make us overeat? Is it just that it tastes good? Laura: That's what most of us think, but van Tulleken argues it’s much more subtle. The first biological heist is the destruction of what scientists call the 'food matrix.' Sophia: Hold on, 'food matrix'? What on earth does that mean in simple terms? Laura: Think of an apple. It has fiber, water, sugars, and nutrients all locked together in a physical structure. Your body has to work to break that down. Chewing, digestion—it all takes time and sends signals to your brain that you're getting full. Now, think of apple juice. The matrix is gone. You can drink the calories from five apples in a minute and your body barely registers it. Sophia: Right, you don't feel full at all. Laura: Exactly. The book argues that most UPF is like that apple juice. It's 'pre-chewed' by industrial processes. It’s soft, calorie-dense, and easy to swallow. He cites a landmark study by a researcher named Kevin Hall, where people were put on two different diets—one unprocessed, one UPF—but both were matched for salt, sugar, fat, and fiber. People could eat as much as they wanted. Sophia: And what happened? Laura: On the UPF diet, people automatically ate 500 calories more per day and gained weight. On the unprocessed diet, they lost weight. And when asked, they didn't even report that the UPF diet was more delicious. The main difference was the speed. They ate the soft, easy UPF much, much faster. Sophia: So real food is like a complex puzzle box our body has to unlock, and UPF is like the puzzle is already solved and the prize is just sitting there, so we grab it way too fast? Laura: That’s a great way to put it. And that leads to the second heist: sensory confusion. The flavors in UPF are often a lie. Think of a Pringle. The book describes how that savory, umami flavor hits your tongue and tells your brain, 'Protein is coming! Get ready!' But what actually arrives in your stomach is just a slurry of refined starch and fat. Sophia: It’s like the food is sending a fake text message to my brain, promising nutrients that never show up. And then my brain is like, 'Hey, where's that protein? Better eat another Pringle to find it.' Laura: Precisely. It creates a mismatch between what our senses promise and what our body receives. This constant confusion disrupts our ancient, evolved systems for regulating appetite. We keep eating, searching for the nutrition that was advertised but never delivered.

Sophia: This feels like a conspiracy against our bodies! If it's this bad, why is it everywhere? Why is it even legal? Laura: And that’s the third, and maybe most important, part of the book. It’s not about you or your willpower. It’s about the system. A huge part of the problem, especially in the US, is a regulatory loophole called 'GRAS'—which stands for Generally Recognized As Safe. Sophia: That sounds… reassuringly official. Laura: It sounds it, but it’s not. It was created in the 1950s for common ingredients like salt and vinegar. But since then, it’s become a way for companies to completely bypass FDA safety reviews. They can hire their own panel of experts to self-determine that a new chemical is safe, and they don't even have to tell the FDA. Sophia: You're telling me a company can invent a new additive and just decide for itself that it's safe to put in our food? Laura: Yes. The book tells this unbelievable story of a company, which the author calls Corn Oil ONE, that submitted a GRAS notification to the FDA. An expert reviewing it noticed the molecular diagram they submitted for their corn oil was actually the formula for an HIV drug. Sophia: You cannot be serious. That’s beyond incompetent, that’s terrifying. Laura: It is. And when the FDA pointed out this and other major flaws, the company just withdrew its application. But because of the GRAS loophole, there’s nothing stopping them from selling that oil anyway, as long as their own scientists believe it's safe. We have no idea if it’s in our food right now. Sophia: So the message we always hear—'eat less, move more'—is basically a distraction. It's not about my lack of willpower; it's that I'm living in a food environment that's designed to make me fail. Laura: That is the book's central, powerful conclusion. Van Tulleken argues that obesity isn't a disease of willpower; it's a 'commerciogenic disease.' It’s a disease caused by commerce. He draws a direct parallel to the tobacco industry. For decades, they blamed smokers' 'addictive personalities.' Now we know the product itself was engineered to be addictive. He says UPF is the same.

Sophia: Wow. Okay. After all this, what's the one big takeaway? Are we all just doomed to eat this stuff forever? Laura: The book's ultimate point is that this isn't a diet book; it's a book about power. It’s about recognizing that the problem isn't you, it's the system. The solution isn't just individual choice, but demanding a food environment that isn't actively working against us. It’s about shifting the blame from the consumer to the producer. Sophia: That’s a huge mental shift. It feels both liberating and overwhelming. So what can we actually do? Laura: The book’s first step is surprisingly simple. Don't try to change everything overnight. Just start noticing. Use that rule of thumb: look at the ingredients. If you see something you wouldn't cook with, like xanthan gum or potassium sorbate, just acknowledge it. 'Ah, this is UPF.' The awareness itself is the first, most powerful step. Sophia: I like that. It’s not about guilt, it’s about knowledge. It makes me want to go look at my own pantry right now. I guess that leaves a question for our listeners. Laura: What's that? Sophia: What's one thing in your kitchen right now that you suspect might be UPF? Take a look at the label. You might be surprised. Laura: This is Aibrary, signing off.