A new diet study shows that government healthy eating advice must “catch up” with the latest science and warn people against ultra-processed diets. This is according to the Soil Association, which has launched a campaign to make minimally processed foods accessible and affordable to everyone. So far nearly 20,000 people have signed the petition.
The clinical trial, led by researchers at University College London (UCL) and University College London NHS Trust (UCLH) found that when given nutritionally matched diets, participants lost twice as much weight eating minimally processed foods (MPFs) compared to ultra-processed foods (UPFs).
The trial involved 55 adults following the prescribed diet for eight weeks. Both diets were nutritionally matched in accordance with the Eatwell Guide, the UK government’s official advice on how to eat a healthy, balanced diet. At the end of the study period, both groups lost weight, probably because the nutritional profile of each diet was better than their normal diet, but the effect was higher (2.06% reduction) on the MPF diet compared to the UPF diet (1.05% reduction).
What the findings mean
The findings suggest that, when observing recommended dietary guidelines, choosing minimally processed foods may be more effective for losing weight.
Dr Samuel Dicken, first author of the study from the UCL Centre for Obesity Research and UCL Department of Behavioural Science & Health, says: “Previous research has linked ultra-processed foods with poor health outcomes. But not all ultra-processed foods are inherently unhealthy based on their nutritional profile. The main aim of this trial was to fill crucial gaps in our knowledge about the role of food processing in the context of existing dietary guidance, and how it affects health outcomes such as weight, blood pressure and body composition, as well as experiential factors like food cravings.
“The primary outcome of the trial was to assess percentage changes in weight and on both diets we saw a significant reduction, but the effect was nearly double on the minimally processed diet. Though a 2% reduction may not seem very big, that is only over eight weeks and without people trying to actively reduce their intake. If we scaled these results up over the course of a year, we’d expect to see a 13% weight reduction in men and a 9% reduction in women on the minimally processed diet, but only a 4% weight reduction in men and 5% in women after the ultra-processed diet. Over time this would start to become a big difference.”
The study also looked at related issues, such as control of cravings and found significantly greater improvements in the number of cravings and ability to resist them on the MPF diet compared to the UPF diet.
Professor Chris van Tulleken, an author of the study from UCL Division of Infection & Immunity and UCLH, adds: “The global food system at the moment drives diet-related poor health and obesity, particularly because of the wide availability of cheap, unhealthy food. This study highlights the importance of ultra-processing in driving health outcomes in addition to the role of nutrients like fat, salt and sugar. It underlines the need to shift the policy focus away from individual responsibility and on to the environmental drivers of obesity, such as the influence of multinational food companies in shaping unhealthy food environments.
“Stakeholders across disciplines and organisations must work together and focus on wider policy actions that improve our food environment, such as warning labels, marketing restrictions, progressive taxation and subsidies, to ensure that healthy diets are affordable, available and desirable for all.”
The Eatwell Guide
This study comes only a few months after a Soil Association investigation found that the previous government U-turned on plans to back minimally processed foods after months of persistent lobbying by the food manufacturing sector.
As part of its campaign, ‘The Whole Truth about ultra-processed food’, the Soil Association is renewing its calls for the government to take steps to prioritise healthier food, and update the Eatwell Guide.
Soil Association Head of Food Policy Rob Percival says: “This is the most rigorous study of ultra-processed diets ever conducted, and it shows that processing really does matter for health. For decades, the UK Government’s ‘healthy eating’ guidelines have neglected processing, assuming that whole foods and ultra-processed products might deliver the same health outcomes. We now know that to be false. A minimally processed diet is better for your health. You cannot replicate the benefits of whole foods in an industrial manufacturing facility – nature knows better.
“Our government must catch up. Its so-called ‘Eatwell Guide’ should be updated to promote healthy, minimally processed foods, and to warn against ultra-processed diets, or else it risks becoming a ‘Eat Badly Guide’. In tandem, the government must use its Food Strategy to make it easy for everyone to access and enjoy more minimally processed produce.”
