The November Broken Science Medical Society Journal Club, hosted by Pete and Bob, focused on ultra-processed foods (UPFs), which are a “hot topic” in health, social media, and politics. The discussion aimed to define UPFs and provide context for their potential effects on health. UPFs are categorized using the NOVA classification system, which divides food into four groups based on the nature, extent, and purpose of processing. The definition of UPFs, particularly the inclusion of ingredients “never or rarely used in kitchens,” is considered subjective. The central argument for the UPF movement, advanced by figures like Carlos Monteiro (who coined the term “ultra-processed food” in 2009) and Michael Pollan, is that the extent of processing is the most important factor linking nutrition and chronic diseases, not the food or nutrients themselves.

Bob and Pete reference Kevin Hall’s “landmark trial” suggesting UPFs cause excess caloric intake. The conversation challenged the claim that processing is solely responsible for chronic diseases, noting that studies often rely on subjective recall (observational data) and that healthy populations like the Maasai and Inuit have vastly different diets, some rich in fat and meat. They discussed the idea that the effort of cooking, even “junk food,” acts as a barrier to overconsumption. The meeting concluded by emphasizing the difficulty of generating objective, reliable knowledge in nutrition research.

Featured papers:

• Monteiro et al. (2019): Ultra-processed foods: what they are and how to identify them
• David S. Ludwig (2025): Ultraprocessed Food on an Ultrafast Track

A 10-minute summary of the webinar is available here free, for anyone, while the full video is available for Medical Society Members and MetFix affiliates in their dashboard.