A homemade puree can drive calorie intake upward just as readily as any supermarket product.
A consortium of researchers from Copenhagen, Wageningen, and Liverpool has quietly redrawn the map of nutritional blame, concluding that industrial processing itself is not what makes ultra-processed food fattening. The true culprits — soft texture, caloric density, excess sodium, and absent fiber — are properties that can appear in any kitchen, not just any factory. In unsettling the popular narrative, the study invites a harder and more useful question: not how food is made, but what it is made of and how it behaves inside the body.
- Five of the most rigorous dietary trials ever conducted have been reanalyzed — and their data quietly contradicts the story the world has been telling about ultra-processed food.
- Soft textures accelerate eating so dramatically that the body's own fullness signals arrive too late, turning every spoonful into a small act of overconsumption before the brain can intervene.
- In studies where calories were supposedly equalized, participants on ultra-processed diets still gained weight — explained by fiber levels four times lower and sodium levels 150 percent higher than the comparison diets.
- The NOVA classification system, now embedded in public health policy worldwide, is drawing fire for treating a bag of chips and a fortified yogurt as equivalent threats.
- Researchers argue the real levers of weight gain — density, texture, salt, fiber — cross all processing categories, meaning current dietary guidance may be solving the wrong problem entirely.
A careful review of the five most rigorous studies on ultra-processed food has arrived at a conclusion that unsettles much of the recent alarm: industrial processing itself is not the driver of weight gain. Researchers from Copenhagen, Wageningen, and Liverpool universities point instead to something more mundane — the softness of the food, its calorie density, its salt content, and its lack of fiber.
The texture finding is particularly revealing. Ultra-processed meals in the trials were significantly softer than their comparison counterparts, causing participants to eat faster than the body's satiety signals could respond. Lead author Faidon Magkos notes that a homemade puree can drive calorie intake just as readily as any supermarket product — the factory is not the problem, the softness is.
Calorie density compounds the issue. In three of the five studies, ultra-processed meals contained between 0.33 and 1 additional calorie per gram. That difference alone, the researchers argue, mathematically accounts for all observed weight gain — no mysterious industrial effect required.
Where calories were fixed in advance, fiber and sodium told the rest of the story. In one trial, participants eating ultra-processed food gained 1.35 kilograms over three weeks despite theoretically matching the control group's energy intake. The unprocessed diet contained four times the fiber — 48 grams daily versus 12 — reducing net energy absorbed during digestion. The remaining weight gain traced to water retention from sodium levels 150 percent higher in the industrial diet.
The researchers close with a structural warning: the NOVA classification system, which groups all ultra-processed items together, creates false equivalences now embedded in public health policy. Until dietary guidance learns to target the actual mechanisms — texture, density, sodium, fiber — the conversation about food and health will continue to aim at the wrong thing.
A careful review of the world's five most rigorous studies on ultra-processed food has arrived at a conclusion that upends much of the recent alarm: the industrial processing itself is not the culprit behind weight gain. Instead, researchers from Copenhagen, Wageningen, and Liverpool universities point to something far more mundane—the softness of the food, its calorie density, the salt it contains, and the fiber it lacks.
These five randomized controlled trials represent the gold standard of nutritional science, the kind of studies that isolate variables in carefully managed conditions and therefore carry real weight in the scientific conversation. Yet when researchers examined them closely, they found that the data tells a different story than the headlines have suggested. The processing label alone cannot bear the blame for the extra kilos.
The texture question is revealing. In the experiments, the ultra-processed meals were significantly softer than their control counterparts. Because they required less chewing, participants ate faster—so fast that the body's satiety signals never caught up before excess calories had already been consumed. Faidon Magkos, the lead author and a nutrition professor at Copenhagen University, makes the point plainly: a homemade puree or soft dish can drive calorie intake upward just as readily as any supermarket product. The softness is the problem, not the factory.
But texture is only part of the story. The researchers also found that the ultra-processed meals in three of the studies contained between 0.33 and 1 additional calorie per gram compared to the minimally processed control diets. This difference in calorie density alone, they argue, mathematically accounts for all the weight gain observed—without needing to invoke any mysterious effect of industrial transformation.
When the scientists looked at studies where calories were fixed in advance for both groups, the picture became even clearer. In one outpatient trial, participants eating ultra-processed foods gained 1.35 kilograms over three weeks despite consuming theoretically identical energy to the control group. The explanation lay in fiber: the unprocessed diet contained four times as much—48 grams daily versus 12 in the ultra-processed version. Since fiber reduces the net energy the body absorbs during digestion, this difference alone accounts for more than half the weight gain. The remainder came from water retention triggered by the industrial diet's sodium content, which was 150 percent higher.
The researchers raise a broader concern about how we classify food. The NOVA system, which lumps all ultra-processed items into a single category, creates a false equivalence. It places genuinely harmful products alongside others that are neutral or even beneficial for certain populations. This blunt classification tool is now shaping public health policy, the authors warn, in ways that may be counterproductive. The real drivers of weight gain—texture, calorie density, sodium, fiber—cut across processing categories. Until policy catches up to that reality, the conversation about food and health will remain muddled.
Citações Notáveis
The available controlled trials provide very weak support for a specific effect of ultra-processing on weight regulation independent of established nutritional factors.— Faidon Magkos, Copenhagen University
A Conversa do Hearth Outra perspectiva sobre a história
So the study is saying ultra-processed food isn't actually the problem?
Not quite. It's saying the processing itself isn't the independent culprit. The weight gain happens because of specific properties that often come with processing—but those same properties can show up in homemade food too.
Like what, exactly?
Soft texture is the first one. When food doesn't require much chewing, you eat faster and your brain doesn't get the satiety signal in time. A homemade puree does the same thing as a processed snack cake.
That seems almost too simple.
It is simple. But the studies also found the processed meals were denser in calories and much higher in sodium. When you account for those factors mathematically, the weight gain disappears as a mystery.
What about the fiber difference?
That's where it gets interesting. The unprocessed control diets had four times the fiber. Fiber reduces how much energy your body actually absorbs. That alone explains more than half the weight gain in one study.
So we've been blaming the wrong thing?
We've been using a category—ultra-processed—that's too broad to be useful. It lumps together things that are genuinely harmful with things that might be fine. The real culprits are specific: texture, calories, sodium, fiber. Those matter regardless of where the food came from.
Does that change how we should think about food policy?
It should. Right now policy is built on a binary classification that doesn't match the actual science. If we want to address weight gain, we need to target the real variables, not the processing label.