Why ultra-processed foods aren’t the real villain behind overeating

Governments are responding with bold ideas such as warning labels, marketing limits, extra taxes, and even bans near schools. But how much of this urgency is supported by solid science?

What Makes Us Eat More Than We Need?

My colleagues and I wanted to step back and ask: what really makes people enjoy certain foods? And what causes them to keep eating when they're no longer hungry? To explore these questions, we studied over 3,000 adults in the UK and collected their reactions to more than 400 everyday foods. The results challenge the simple "UPF equals unhealthy" narrative and point to a more complex story.

In nutrition discussions, two ideas are often mixed up: liking and hedonic overeating (eating for pleasure rather than hunger). Liking refers to taste, while hedonic overeating describes continuing to eat because it feels rewarding. They're related but not the same. Many people enjoy porridge but rarely binge on it, while chocolate, biscuits, and ice cream are common indulgences.

How the Study Worked

We ran three large online surveys where participants viewed unbranded photos of common foods and rated how much they liked each and how likely they were to overeat it. The foods represented a typical UK shopping basket: jacket potatoes, apples, noodles, cottage pie, custard creams -- more than 400 in total.

We then compared these ratings with three sets of data: the foods' nutritional profiles (including fat, sugar, fiber, and calorie density), their classification by the Nova system -- a method that categorizes foods by how and why they're processed -- and how people perceived them (for example, whether they seemed sweet, fatty, processed, or healthy).

How Beliefs Shape Appetite

Some findings were expected: people liked foods they ate often, and calorie-dense foods were more likely to lead to overeating.

But the more surprising insight came from the role of beliefs and perceptions. Nutrient content mattered -- people rated high-fat, high-carb foods as more enjoyable, and low-fiber, high-calorie foods as more "bingeable." But what people believed about the food also mattered, a lot.

Perceiving a food as sweet, fatty or highly processed increased the likelihood of overeating, regardless of its actual nutritional content. Foods believed to be bitter or high in fiber had the opposite effect.

In one survey, we could predict 78% of the variation in people's likelihood of overeating by combining nutrient data (41%) with beliefs about the food and its sensory qualities (another 38%).

In short: how we think about food affects how we eat it, just as much as what's actually in it.

Rethinking the "Ultra-Processed" Label

This brings us to ultra-processed foods. Despite the intense scrutiny, classifying a food as "ultra-processed" added very little to our predictive models.

Once we accounted for nutrient content and food perceptions, the Nova classification explained less than 2% of the variation in liking and just 4% in overeating.

That's not to say all UPFs are harmless. Many are high in calories, low in fiber and easy to overconsume. But the UPF label is a blunt instrument. It lumps together sugary soft drinks with fortified cereals, protein bars with vegan meat alternatives.

Some of these products may be less healthy, but others can be helpful -- especially for older adults with low appetites, people on restricted diets or those seeking convenient nutrition.

Why Blanket Warnings Can Backfire

The message that all UPFs are bad oversimplifies the issue. People don't eat based on food labels alone. They eat based on how a food tastes, how it makes them feel and how it fits with their health, social or emotional goals.

Relying on UPF labels to shape policy could backfire. Warning labels might steer people away from foods that are actually beneficial, like wholegrain cereals, or create confusion about what's genuinely unhealthy.

Instead, we recommend a more informed, personalized approach:

• Boost food literacy: help people understand what makes food satisfying, what drives cravings, and how to recognize their personal cues for overeating.
• Reformulate with intention: design food products that are enjoyable and filling, rather than relying on bland "diet" options or ultra-palatable snacks.
• Address eating motivations: people eat for many reasons beyond hunger -- for comfort, connection and pleasure. Supporting alternative habits while maximizing enjoyment could reduce dependence on low-quality foods.

It's About Psychology, Not Just Processing

Some UPFs do deserve concern. They're calorie dense, aggressively marketed and often sold in oversized portions. But they're not a smoking gun.

Labeling entire categories of food as bad based purely on their processing misses the complexity of eating behavior. What drives us to eat and overeat is complicated but not beyond understanding. We now have the data and models to unpack those motivations and support people in building healthier, more satisfying diets.

Ultimately, the nutritional and sensory characteristics of food -- and how we perceive them -- matter more than whether something came out of a packet. If we want to encourage better eating habits, it's time to stop demonizing food groups and start focusing on the psychology behind our choices.

Written by Graham Finlayson, Professor of Psychobiology, University of Leeds and James Stubbs, Professor in Appetite & Energy Balance, Faculty of Medicine and Health School of Psychology, University of Leeds.