#577: Ultra-processed vs. Minimally Processed Diets: UPDATE Trial – Samuel Dicken, PhD

#577: Ultra-processed vs. Minimally Processed Diets: UPDATE Trial – Samuel Dicken, PhD

Author: Danny Lennon September 16, 2025 Duration: 49:38

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


Sigma Nutrition Radio, hosted by nutrition scientist Danny Lennon, moves beyond the noise of diet trends and simplistic advice to explore the complex, fascinating world of human nutrition. This is a space for deep, evidence-based conversations that acknowledge the nuance and often contradictory nature of scientific research. Each episode delves into a specific topic within health, fitness, or dietetics, breaking down the underlying physiology, examining the latest studies, and discussing practical implications with expert guests. The goal isn't to hand out rigid meal plans but to cultivate the critical thinking skills necessary to navigate the ever-changing landscape of nutritional science. You'll hear detailed analyses of how research is conducted, thoughtful debates on contentious issues, and explorations of how evidence translates-or doesn't-into real-world recommendations for different individuals. Tuning into this podcast means committing to a more sophisticated understanding of how food, movement, and metabolism interact, leaving you better equipped to make informed decisions about your own health and skepticism towards the next big headline. Danny’s approach is both rigorous and accessible, making even the most detailed biochemical pathways relevant to everyday life. It’s for anyone who has ever wondered about the real story behind a nutrition claim and values substance over soundbites.
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