Recently a new trial was published in Nature Medicine comparing the effect of ultra-processed versus minimally processed diets. Specifically, the UPDATE trial compared these two diets in the context of a healthy dietary pattern (in line with the UK's EatWell Guide).

This eight-week randomized, crossover trial generated a lot of discussion and was largely seen as being a really useful addition to the evidence base, and providing answers to some previously unexamined questions.

In this episode the study's lead author, Dr. Samuel Dicken, explains the background context for the UPDATE trial, provides an insight into its execution, and puts some of the results in context. There is also a discussion about the current state of evidence more broadly and the leading hypotheses around the mechanisms that drive the observations seen with consuming ultra-processed foods.

This episode is particularly noteworthy because it provides fresh evidence on an important question: does following dietary guidelines with minimally processed foods confer extra benefits over following the same guidelines with ultra-processed foods?

Timestamps

• [02:48] Interview with Dr. Samuel Dicken
• [03:08] Background and research interests of Dr. Samuel Dicken
• [04:31] Details of the update trial
• [09:48] Trial design and methodology
• [15:45] Results and findings of the update trial
• [18:46] Secondary outcomes and craving control
• [25:43] Hypotheses and mechanisms behind UPF effects
• [40:28] Policy implications and future research directions

Related Resources

• Subscribe to Sigma Nutrition Premium
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• Enroll in the next cohort of our Applied Nutrition Literacy course
• Study: Dicken et al., 2025 – Ultraprocessed or minimally processed diets following healthy dietary guidelines on weight and cardiometabolic health: a randomized, crossover trial
• LinkedIn: Samuel Dicken
• X: @SamuelDickenUK