Ultra Processed Foods
We have known for some time that UPFs are bad for our health[1]. The Lancet has now published a major series of 104 studies examining the effects of ultra-processed foods (UPFs) on human health. Taken together, these studies link UPFs to twelve serious conditions including obesity, diabetes, cardiovascular disease, neurodegenerative disease, depression and early morbidity. According to the authors, UPFs are associated with elevated risks across thirty-two different diseases. They now call for UPFs to be banned in public institutions such as schools and hospitals, for limits on supermarket shelf space, and for clear front-of-pack labelling to identify UPFs[2].
What is clear from these papers is that UPF research is about biological mechanisms. Mechanisms that are shared among mammals and therefore also relevant to canine health: the impact of emulsifiers on the mucus layer, the formation of processing contaminants, exposure to AGEs formed by high-heat cooking and the oxidative burden of degraded fats. The Lancet describes consequences such as barrier stress, low-grade chronic inflammation, dysbiosis, endocrine disruption and the accumulation of processing-related toxicants.
So, the question follows: why are we giving our dogs UPFs?
The main thesis and the evidence
“The first hypothesis – that this [dietary] pattern [based on UPFs] is globally displacing long-established diets centred on whole foods and their culinary preparation as dishes and meals – is supported by decades of national food intake and purchase surveys, and recent global sales data. The second – that this pattern results in deterioration of diet quality, especially in relation to chronic disease prevention – is confirmed by national food intake surveys, large cohorts, and interventional studies showing gross nutrient imbalances; overeating driven by high energy density, hyper-palatability, soft texture, and disrupted food matrices; reduced intake of health-protective phytochemicals; and increased intake of toxic compounds, endocrine disruptors, and potentially harmful classes and mixtures of food additives. The third and final hypothesis – that this pattern increases the risk of multiple diet-related chronic diseases through various mechanisms – is substantiated by more than 100 prospective studies, meta-analyses, randomised controlled trials, and mechanistic studies, covering adverse outcomes across nearly all organ systems.”[3]
UPFs are aggressively marketed and engineered to be hyperpalatable, driving repeated consumption and often displacing traditional, nutrient-rich foods[4]. Under the Nova classification system[5], UPFs are branded, commercial formulations made from cheap ingredients (e.g. refined fats and sugars, protein isolates) and combined with food additives (e.g. dyes, artificial sweeteners, emulsifiers) to make the final product look, feel, sound, smell, and taste good.[6] UPFs include not only obvious “junk foods” but also products marketed as healthy, such as light, vegan, organic, or gluten-free formulations, when they are made from refined fractions and additives rather than intact whole foods[7].
This framing matters: humans and dogs share a striking degree of gastrointestinal similarity. Around 60%[8] of the taxonomic and functional landscape of the gut microbiome overlaps between the two species. Dogs are increasingly used as models for studying human gut physiology and gut homeostasis[9]; canine and human IBD share molecular features[10]; and the immunological handling of dietary AGEs appears broadly consistent across mammalian systems[11].
The response of pathways to processing is exactly the biological terrain UPF research sits on. So, if such a large percentage of the microbiome’s taxonomic and functional landscape is shared, and diet pushes dog and human microbiota in similar directions, then UPFs are not just a concern for humans, but also for our dogs.
And while canine studies into long-term morbidity lag behind the emerging human research into UPF, they do show mechanistic responses to processing that fall within the same biological pathways. Dogs and humans share tight-junction proteins, mucus-layer architecture, microbiome fermentation pathways and production of SCFAs, inflammatory responses to oxidised fats, and the receptor systems involved in recognising Maillard reaction products (MRPs/AGEs).
Canine studies confirm several of these effects directly:
- high AGE exposure from extruded diets;
- increased oxidative-stress markers with oxidised fats;
- reversible microbiome and SCFA shifts between extruded and fresh diets;
- inflammatory and metabolic marker differences across diet formats;
- comparison[12] of raw, lightly processed, and extruded diets found clear differences in microbiota profiles and fermentation end-products;
- moving dogs off dry extruded food altered microbiota diversity and metabolite patterns, changes which reversed when the dogs were returned to dry food[13].
One of the authors of the Lancet study, Professor Carlos Monteiro (University of Sao Paulo, Brazil) says, “The growing consumption of ultra-processed foods is reshaping diets worldwide, displacing fresh and minimally processed foods and meals. This change in what people eat is fuelled by powerful global corporations who generate huge profits by prioritising ultra-processed products, supported by extensive marketing and political lobbying to stop effective public health policies to support healthy eating.”
So why are we still giving our dogs UPFs?
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References
[1] https://www.economist.com/the-economist-explains/2023/08/07/what-makes-ultra-processed-foods-so-bad-for-your-health?
[2] Professor Barry Popkin, University of North Carolina, US, says “We call for including ingredients that are markers of UPFs (e.g., colours, flavours, and sweeteners) in front-of-package labels, alongside excessive saturated fat, sugar, and salt, to prevent unhealthy ingredient substitutions, and enable more effective regulation.”
[3] Ultra-processed foods and human health: the main thesis and the evidence (Lancet, Nov 18, 2025)
[4] Ultra-processed foods: time to put health before profit (Lancet, Nov 18, 2025)
[5] https://world.openfoodfacts.org/nova
[6] Ultra-processed food: from first tastes to lifelong habits (Lancet, Nov 18, 2025)
[7] Capozzi F, Magkos F, Fava F, Milani GP, Agostoni C, Astrup A, Saguy IS. A Multidisciplinary Perspective of Ultra-Processed Foods and Associated Food Processing Technologies: A View of the Sustainable Road Ahead. Nutrients. 2021 Nov 5;13(11):3948. doi: 10.3390/nu13113948. PMID: 34836203; PMCID: PMC8619086.
[8] Coelho L. P., Kultima J. R., Costea P. I., Fournier C., Pan Y., Czarnecki-Maulden G., et al. (2018). Similarity of the Dog and Human Gut Microbiomes in Gene Content and Response to Diet. Microbiome 6 (1), 72. 10.1186/s40168-018-0450-3
[9] Beretta S, Apparicio M, Toniollo GH, Cardozo MV. The importance of the intestinal microbiota in humans and dogs in the neonatal period. Anim Reprod. 2023 Nov 10;20(3):e20230082. doi: 10.1590/1984-3143-AR2023-0082. PMID: 38026003; PMCID: PMC10681130.
[10] Kopper JJ, Iennarella-Servantez C, Jergens AE, Sahoo DK, Guillot E, Bourgois-Mochel A, Martinez MN, Allenspach K, Mochel JP. Harnessing the Biology of Canine Intestinal Organoids to Heighten Understanding of Inflammatory Bowel Disease Pathogenesis and Accelerate Drug Discovery: A One Health Approach. Front Toxicol. 2021 Nov 10;3:773953. doi: 10.3389/ftox.2021.773953. PMID: 35295115; PMCID: PMC8915821.
[11] Teodorowicz M, Hendriks WH, Wichers HJ, Savelkoul HFJ. Immunomodulation by Processed Animal Feed: The Role of Maillard Reaction Products and Advanced Glycation End-Products (AGEs). Front Immunol. 2018 Sep 13;9:2088. doi: 10.3389/fimmu.2018.02088. PMID: 30271411; PMCID: PMC6146089.
[12] Sandri M, Dal Monego S, Conte G, Sgorlon S, Stefanon B. Raw meat based diet influences faecal microbiome and end products of fermentation in healthy dogs. BMC Vet Res. 2017 Feb 28;13(1):65. doi: 10.1186/s12917-017-0981-z. PMID: 28245817; PMCID: PMC5331737.
[13] Herstad KMV, Gajardo K, Bakke AM, Moe L, Ludvigsen J, Rudi K, Rud I, Sekelja M, Skancke E. A diet change from dry food to beef induces reversible changes on the faecal microbiota in healthy, adult client-owned dogs. BMC Vet Res. 2017 May 30;13(1):147. doi: 10.1186/s12917-017-1073-9. PMID: 28558792; PMCID: PMC5450340.
Important Considerations:
- Always consult your veterinarian before making any significant dietary changes, particularly where there are pre-existing health conditions or dietary restrictions.
- If you are feeding commercial food, check the label for ingredients before giving more. Excessive intake of any foods can have adverse effects.
- Ensure (where possible) that you use high-quality, organic products specifically formulated for pets (or better still, human grade ingredients) to avoid any potential adverse effects.
- Introduce new foods gradually to avoid adverse effects such as gastrointestinal upset or diarrhoea.
- I provide nutritional information purely as a helpful guide. Nutritional information on ingredients is obtained from the US Department of Agriculture’s FoodData Central site (https://fdc.nal.usda.gov/index.html) and any nutritional information provided in recipes is based on an online calculator: calories and other information will vary based on brands, ingredients and other factors.
- Check nutrient levels and recommendations for your dog’s weight, age and activity. For example this nutritional guideline produced by FEDIAF.
- I am not a professional canine nutritionist but supporting research is cited.
- The recipes shared were created by me and tested in my kitchen – and tasted and approved by our doggy friends!