Do minimally processed foods really help you lose weight? 

This post was written by Lexie Lei and Sinead Rhodes

Have you ever been told that the secret to losing weight is just to “cook more and avoid processed food”? It sounds like an easy way; just ditch the packaged meals and the kilos will take care of themselves. But could it really be that simple? Let’s look at what the study actually found, and how the media told the story. 

That’s the message that came across in a recent piece in The Guardian. The article told readers that people who took part in a study lost about twice as much weight on a minimally processed diet compared with an ultra-processed one. It suggested that how food is processed might be the key to whether the weight comes off or not. 

The tone felt friendly and practical, almost like advice from a health-conscious friend telling you to cook more from scratch. But the media didn’t spend much time on how the study was actually done, or what the numbers really mean in everyday life. That’s where things get more interesting. 

The study behind the headlines was led by University College London and published in Nature Medicine. A group of 43 adults agreed to let researchers plan every meal they ate for two eight-week periods. For part of the time, most of their food was minimally processed, like oats, vegetables, and lean meat. For the other part, most of their food was ultra-processed, like ready meals, packaged cereals, snack bars, but still designed to meet NHS healthy eating guidelines. 

On paper, the two diets looked very similar: the same calories, fat, sugar, and fibre. By the end of the period, there was a small difference in scales. On the minimally processed plan, people lost about 2% of their body weight; on the ultra-processed one, about 1%. For someone who weighs 90 kilos, that’s roughly 1.8 kg versus 0.9 kg over eight weeks, a difference of around one bag of sugar. 

Why might that happen? People eating less processed food tended to feel fuller and ate fewer calories overall, but researchers did not claim that food processing directly causes weight gain. 

There are also details the media didn’t mention. “Ultra-processed” is a very broad label under the NOVA system, covering everything from fizzy drinks to fortified breakfast cereals. In this study, many of the ultra-processed options were still nutritionally balanced. And this was a short, tightly controlled trial with free meals in boxes. It is very different from standing in your kitchen wondering what to cook after a long day. 

Other outlets told the story in their own way. ITV News spoke to people in the trial who said they slept better and had more energy after cutting back on ultra-processed foods. That made the piece feel hopeful and human, even though the headline still suggested weight loss “speeds up”. The Science Media Centre used experts to stress the short trial, and the British Heart Foundation offered advice and noted that ultra-processed foods can fit a healthy diet. 

Comparing these sources shows how tone and framing shape our understanding of science. ITV News made the story personal and upbeat, Science Media Centre focused on evidence and caution, and British Heart Foundation put it into a public-health context. Reading across them helps reveal both the excitement and the limits of new research. 

It’s tempting to take headlines as simple advice: “avoid all processed foods.” But that’s neither realistic nor necessary. Both diets in this study were healthy. What matters most is the pattern, including balance, variety, and mindful eating, not whether something came from a packet. 

This study adds a useful piece to the nutrition puzzle but doesn’t rewrite it. Less-processed foods might help, but no single trial offers the full recipe for good health. As always, it pays to read beyond the headline.