A ground-breaking study by Rosetrees-funded researchers at UCL has revealed that people eating minimally processed foods lost twice as much weight as those on ultra-processed diets, even when both groups consumed nutritionally identical meals.

The research, published in Nature Medicine, followed 55 adults through a carefully designed 20-week trial. Participants alternated between either minimally processed or ultra-processed diets for eight weeks each, with a four-week break in between to return to their normal eating habits.

Both groups received home-delivered meals and were encouraged to eat as much as they normally would. The results were striking: those eating minimally processed foods lost twice as much weight as the ultra-processed group.

Beyond the scale, the minimally processed diet also delivered additional health benefits. Participants lost more fat and water weight, leading to improved body composition. They also experienced significantly fewer food cravings and demonstrated four times better craving control compared to those on the ultra-processed diet.

This first-of-its-kind study compared the two diet types under real-world conditions, providing valuable insights for public health policy. The research was also supported by the National Institute for Health and Care Research UCLH Biomedical Research Centre.