SHIFT Newsroom · UK
Less-processed food and weight loss: what a UK trial found
UK archive · Original report: 4 August 2025. A small UK feeding trial compared two diets that both followed healthy-eating guidance. The result deserves attention, with limits.
UK archive review · 13 September 2026. Original source: 4 August 2025. This article revisits a UK development; it is not a new announcement today.
What the researchers tested
UCL researchers recruited 55 adults for a trial comparing minimally processed and ultra-processed diets designed to meet the UK's Eatwell guidance. Participants received each diet for eight weeks, separated by a washout period. Food was delivered to their homes without charge.
The reported average weight reduction was 2.06% during the minimally processed diet and 1.05% during the ultra-processed diet. Fifty participants completed at least one diet period. Both approaches produced weight loss; this was not a comparison between healthy eating and unrestricted junk food.
What the result cannot tell us
Eight weeks cannot establish whether a difference lasts for years. Free food delivery also removes costs and planning pressures that matter in an ordinary household. The trial does not establish a specific result for men or show that every processed food should be excluded.
The useful question for everyday life
For SHIFT readers, the practical question is which affordable meals they could repeat comfortably. A workable shopping list, time to cook and food that the household enjoys are more useful starting points than a perfect-food rule. Those are our editorial questions, rather than outcomes measured by this trial.
Treat the study as a reason to examine food patterns, not a promise of a particular personal weight-loss result.
What this means in the UK
UK household cost and convenience remain important questions when applying a controlled feeding study to everyday weight management.
Known facts
- The UK trial compared two diets designed around Eatwell guidance over eight-week periods.