Picture this: a man sits down for dinner every single night, and for 25 years, dinner has been exactly the same thing. Not a rotating menu. Not a craving now and then. Cheese pizza — every day, for a quarter of a century. No salad. No vegetables. Not even a different topping.
It sounds impossible. It sounds like a dare that should have ended badly within a month. But Dan Janssen, a woodworker from Ellicott City, Maryland, claims he has done exactly that — and when he walked into a doctor’s office, even the doctors couldn’t believe what the blood tests showed.
His story went viral after being covered by the Baltimore Sun, UPI, Medical Daily, and Men’s Journal, and later became the subject of a Vice documentary. And the more you learn about what he eats — and what he doesn’t — the more shocking it gets.
Meet Dan Janssen: 25 Years of Cheese Pizza
Dan Janssen is the founder of Imperium Woodcraft, a woodworking business in Maryland. He was 38 years old when his story exploded across the internet around 2015 and 2016. By his own account, he had been eating almost nothing but cheese pizza for 25 years — meaning the habit began when he was just a teenager.
His daily diet sounds like a teenager’s dream and a nutritionist’s nightmare: a whole 14-inch plain cheese pizza, often eaten in a single day. Sometimes he eats it for lunch. Sometimes for dinner. Sometimes for both. He rotates brands — frozen pizzas, local pizzerias, homemade versions — but the one constant is that it is always plain cheese pizza. No pepperoni. No vegetables on top. Just cheese, sauce, and crust.
Breakfast? He almost never eats it. Just coffee. Once a week, he eats a bowl of Raisin Bran — which he describes as his one concession to health. “To be healthy,” he jokes, as if a weekly bowl of bran cereal could balance out the thousands of pizzas.
How It Started: A Teenager Who Hated Vegetables
At age 14, Janssen became a vegetarian for ethical reasons. It was a principled decision — he didn’t want animals to die for his meals. But there was a problem: he absolutely hated vegetables.
This left him in a strange position. He refused to eat meat, and he refused to eat vegetables. So what was left? Cheese pizza. It was vegetarian, it was cheap, it was everywhere, and — most importantly — it was the only food he genuinely liked.
“Why should I eat a carrot when I can eat pizza?” he told reporters, a line that became the defining quote of his story. What started as a convenient teenage solution simply never stopped. One year became five. Five became ten. Ten became 25.
Over time, his limited diet hardened into something psychologists recognize: a powerful food aversion. He has said openly that the thought of most foods makes him uncomfortable. His fiancée, Madeline, eventually convinced him to see a therapist about his relationship with food — one of the few times he has publicly admitted the habit might be a problem worth addressing.
What He Eats Every Day
Let’s be specific, because the details are what make this story hard to believe. On a typical day, Janssen eats an entire 14-inch cheese pizza. That’s roughly eight slices — somewhere between 1,600 and 2,000 calories from a single food, plus the coffee he drinks instead of breakfast.
He doesn’t stick to one brand or one pizzeria. He buys frozen cheese pizzas, orders from local pizza shops, and sometimes makes them at home. The variety, such as it is, comes from the source — never from the food itself. It is always plain cheese pizza. Always.
There was one exception, and it lasted exactly two weeks. On a trip to Germany, he couldn’t find pizza he considered good enough, so he ate pretzels instead. For 14 days, pretzels were his entire diet. Then he came home, and the pizza routine resumed as if nothing had happened.
The Doctor’s Visit That Shocked Everyone
Here is the part of the story that made it go viral. Janssen developed hereditary diabetes — diagnosed right around the time his pizza-only diet began. For a man eating an entire pizza a day, diabetes should have been devastating. Refined flour and cheese, day after day, is practically a recipe for blood sugar disaster.
His endocrinologist was concerned, naturally. But then came the twist that nobody expected. Other doctors who examined him were stunned by the results: “Your cholesterol is fine. You seem healthy. Keep doing what you’re doing.”
Keep doing what you’re doing. That sentence — directed at a man who hadn’t eaten a vegetable in 25 years — is what turned a local oddity into a global story. How could his cholesterol be fine? How could his body tolerate this?
Part of the answer may be his lifestyle. Janssen is thin and extremely active. He rides his bicycle 30 to 40 miles at a time — distances that would exhaust most people. He told reporters, “I feel great.” Exercise, genetics, and youth may have been shielding him from the worst consequences of his diet for years. But doctors who study nutrition are quick to add a warning: feeling fine now is not the same as being fine forever.
The Hidden Cost: Diabetes and Sugar Crashes
The story isn’t all good news, and Janssen doesn’t pretend it is. Living with hereditary diabetes while eating a high-carbohydrate diet is genuinely risky. And the Vice documentary that followed him reported something concerning: occasional episodes where his blood sugar crashed and he blacked out. He downplayed the severity of these episodes, but they happened — a reminder that even a body that “feels great” can hit limits.
Diabetes and an all-pizza diet are a dangerous combination. The refined carbohydrates in pizza crust spike blood sugar quickly, and eating little else means the body gets almost no fiber, vitamins, or minerals from food. That his cholesterol numbers stayed normal is remarkable — but cholesterol is only one measure of health, and it says nothing about vitamin deficiencies, gut health, or long-term organ damage.
His fiancée Madeline’s push for therapy was the first sign that Janssen himself was beginning to reckon with the psychological side of his diet. A food aversion strong enough to eliminate every other food for 25 years isn’t just a quirk — it’s a real condition, and getting help for it took courage.
What Doctors and Nutritionists Say
So could you do what Dan Janssen did? Every nutrition expert who has commented on cases like his gives the same answer: absolutely not — and his story should never be taken as proof that it works.
A diet of only cheese pizza is missing almost everything the human body needs: fiber, vitamin C, vitamin A, iron from varied sources, antioxidants, and the thousands of plant compounds found in fruits and vegetables. Over years, such deficiencies can cause serious problems — from weakened immunity to nerve damage to bone loss. That Janssen appears to have dodged the worst of it so far is a matter of luck and genetics, not a strategy.
Doctors also point out that “fine” blood work at 38 doesn’t guarantee anything at 50. The damage from decades of nutritional deficiency can be slow and silent. By the time symptoms appear, the harm can be difficult to reverse.
The bottom line from the medical world: Dan Janssen’s story is fascinating, but it is a cautionary tale, not a diet plan. He is the exception that proves the rule — and even he, with hereditary diabetes and sugar-crash blackouts, is paying a price.
Frequently Asked Questions
Who is the man who ate pizza for 25 years?
Dan Janssen, a woodworker from Ellicott City, Maryland, and founder of Imperium Woodcraft. His story went viral around 2015–2016 through the Baltimore Sun, UPI, Medical Daily, Men’s Journal, and a Vice documentary.
What exactly does he eat?
Almost exclusively plain cheese pizza — usually a whole 14-inch pizza a day, sometimes for both lunch and dinner. He drinks coffee instead of breakfast and eats a bowl of Raisin Bran once a week. On a two-week trip to Germany, he ate only pretzels.
Why did he start eating only pizza?
At 14, he became vegetarian for ethical reasons but hated vegetables. Cheese pizza was the only food he liked that fit his principles. The habit hardened into a lasting food aversion.
Is he healthy?
Doctors told him his cholesterol was fine and he appeared healthy, and he stays thin and active, biking 30–40 miles. But he has hereditary diabetes, and Vice reported occasional sugar-crash blackouts. Doctors warn his case is luck and genetics, not a safe diet.
Can I try eating only pizza?
No. Nutritionists are unanimous: a pizza-only diet lacks fiber, vitamins, and essential nutrients, and can cause serious long-term harm. Janssen’s story is a curiosity, not a recommendation.
