Cutting back on ultra-processed foods (UPFs) like crisps, sweets, and ready meals could significantly boost weight loss, according to new research by British scientists. The study found that participants who followed a diet rich in minimally processed foods lost nearly twice as much weight as those who continued to consume high levels of UPFs.
The eight-week study tracked 50 adults with diets high in UPFs. Participants were split into two groups: one group was given a diet of home-cooked meals such as spaghetti bolognese and overnight oats, while the other consumed meals like lasagna ready meals and oat bars. After the initial phase, the groups swapped diets.
Despite both diets being nutritionally similar in terms of fat, protein, carbs, salt, and fiber—as outlined in the UK’s Eatwell Guide—participants on the minimally processed diet lost 2.06% of their body weight, compared to just 1.05% for those on the UPF-heavy diet. Researchers also noted that the UPF diet didn’t lead to significant fat loss or changes in other health markers like blood pressure, liver function, or cholesterol.
Dr. Samuel Dicken of University College London, a co-author of the study, said the findings support previous concerns about UPFs but also stressed that not all UPFs are automatically unhealthy. “We saw significantly greater weight loss on the minimally processed food diet,” he said. “But not all ultra-processed foods are inherently unhealthy based on their nutritional profile.”
In addition to aiding weight loss, the minimally processed diet also appeared to reduce food cravings—making it easier to stick to healthier habits long-term.
