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The arguments against ultra-processed foods
August 2025 | Gut Advisor Monthly Newsletter
Lisa Goehler
August 24, 2025
Hi friends!
The health risks of ultra-processed foods (UPFs) – those that are mass-produced and typically contain additives such as coloring and preservatives – have been attracting research attention lately, and the findings pretty much confirm what you might expect. Diets high in UPFs are prominent risk factors for a wide variety of health-related conditions, from metabolic syndrome (Zhang 2025), gut disorders, (Chen 2023) and mood disorders (Lane 2024).
But what are ultra-processed foods? Monteiro et al (2019) defines them as the following:
“Ultra-processed foods are defined within the NOVA classification system, which groups foods according to the extent and purpose of industrial processing. Processes enabling the manufacture of ultra-processed foods include the fractioning of whole foods into substances, chemical modifications of these substances, assembly of unmodified and modified food substances, frequent use of cosmetic additives and sophisticated packaging. Processes and ingredients used to manufacture ultra-processed foods are designed to create highly profitable (low-cost ingredients, long shelf-life, emphatic branding), convenient (ready-to-consume), hyper-palatable products liable to displace all other NOVA food groups, notably unprocessed or minimally processed foods.”
A practical way to identify an ultra-processed product is to check to see if its list of ingredients contains at least one item characteristic of the NOVA ultra-processed food group, which is to say, either food substances never or rarely used in kitchens (such as high-fructose corn syrup, hydrogenated or interesterified oils, and hydrolyzed proteins), or classes of additives designed to make the final product palatable or more appealing (such as flavors, flavor enhancers, colors, emulsifiers, emulsifying salts, sweeteners, thickeners, and anti-foaming, bulking, carbonating, foaming, gelling and glazing agents).” Monteiro et al. 2019.
I decided to test this definition myself
I try to cook with as minimally processed foods as I can, but I have always felt a little guilty about relying on cans of beans for the many meals I cook that contain them. I know it is better to cook them myself (right?) but somehow it always takes days to cook them to how I like them to be, no matter that I take all the advice on preparing them to make them cook faster. Hence my reliance on cans. So I checked the label. How many bad things are in there? Well, there are beans, water, and salt. All things in my kitchen. Yay!
Dr. Lisa Goehler
Table of Contents
What about “healthy” processed food?
One problem in determining just what about ultra-processed food is bad is that such foods are typically low in nutrients, so it’s hard to know whether the problems UPFs may cause is due to nutritional deficiencies, or to something about the processing itself.
A paper by Dicken et al. was published early this month in Nature Medicine and has addressed this by comparing “healthy” ultra-processed foods (UPFs) and minimally-processed foods (MPF) on measures of weight loss and related measures. All of the foods provided to the participants, both UPFs and MPF, met the standards for “healthy diet” in the UK (the “Eatwell guide”).
The study had a “crossover” design, such that everyone in the study did 8 weeks of each diet, with a “wash out” period in between. This design reduces effects of individual differences in vulnerability or response to the diets.
As this was a study containing all “healthy” foods, there were only a few differences. The minimally processed foods led to more weight loss, and less body fatness, although the usual metabolic measures (cholesterol, blood pressure etc.) were similar. The most interesting thing to me, though, were the reports of “adverse symptoms/events”. When on the ultra-processed “healthy” diet, participants reported gut symptoms, especially constipation and gastrointestinal reflux (GERD) as well as mood symptoms and especially fatigue, at much higher rates than when they were on the minimally processed diet.
This indicates that anyone concerned about reducing gut and mood symptoms should avoid ultra-processed foods, even if they claim to be “healthy” (such as protein bars etc.).
The gluten free diet craze has been a boon for industrial food
I’ve noticed when shopping that there a lot of food items that advertise themselves as gluten-free, even foods, such as soda, that never have had gluten! When looking at the ingredients it has seemed to me that many of the gluten free items, especially snacks, have a lot of ingredients typical of ultra-processed foods. My impression has been validated by a study from Canada that found that gluten-free products are more likely to contain ultra-processed ingredients than non-gluten free (Vergeer 2021), and that less processed food items were also less likely to be gluten free. This has implications for people with celiac disease, as another study found that celiac disease patients who consumed more ultra-processed gluten free food had more evidence of oxidative stress and inflammation than those consuming a more Mediterranean type diet. (Nestares 2021).
This is concerning because many people assume that gluten is “bad”, and that a healthy diet is gluten-free. However, a study comparing gluten free and gluten containing foods from menus provided by the United States Department of Agriculture for MyPlate ”healthy” found that the gluten free diet was in fact not healthier than the gluten containing diet (Taetzsch 2018). Most notably, the gluten free diet was significantly deficient in fiber, and some other nutrients, including folate (Cardo 2021) and higher in sugars and fats. Low fiber diets are associated with a range of problems, especially gut problems, stemming from the fact that fiber in the diet is critical for maintaining a population of beneficial gut microbes. Another concern is that many gluten free diets rely heavily on rice as an alternative to gluten containing grains, especially the ultra-processed gluten free foods. Unfortunately, rice commonly contains heavy metals, especially arsenic, which might have implications for health. (Bascuñán 2023).
From these studies it is clearly important that people with celiac disease should make an effort to get enough fiber. Good sources of gluten free fiber include fresh fruits and vegetables, legumes (beans, chickpeas, lentils), quinoa, nuts, and seeds. It is also important that gluten free diets not rely too heavily on rice, and ultra-processed foods.
All disease results from ultra-processed foods.
Where does this claim come from?
I’ve been seeing claims that “all disease results from ultra-processed foods”, with the major mechanism being effects on health mitochondria (the “power houses of the cell”). The idea is that UPFs induce oxidative stress, which is well-established to damage mitochondria, and that taking certain supplements can protect from mitochondrial damage.
More alarming, I’ve seen claims that people with serious conditions such as lupus, a difficult to manage autoimmune condition, don’t need high tech immune modulating treatments. Rather they just need to fix their diets and their bodies “will heal itself”. Of course, the supplements and “healthy diet” fads popping up to enhance this process.
Is it true that taking mitochondrial boosting supplements and avoiding ultra-processed foods can obviate the need for drugs or other contemporary therapies (such as immune-related therapies) for serious diseases such as cancer, IBD, or lupus?
Kernel of truth
Mitochondria are indeed critically important for cell function and health, and most, if not all, disease involves mitochondria damage or dysfunction. Mitochondria should be protected from damage. And the idea that some of the health risks of ultra-processed foods could relate to oxidative stress, and hence mitochondrial damage, is not unreasonable.
Distortion beyond all likely evidence
There is no evidence that supplements actually protect mitochondria from damage in humans. And unfortunately, even if there were clinical studies showing benefits, there is no way of knowing if they would help in the real world. This is partly because of genetic differences between people related to, for instance, susceptibility to inflammation vs. resilience, and the varied and complex ways these are regulated. But there is also the standard problem with supplements- that they by law cannot be regulated. So we have no way of knowing what is in them.
But I also get the feeling that this is another version of the (historically popular) attitude that allows “healthy” people to look down on people who have illnesses. Added to the proliferation of supplements targeted toward protecting mitochondria that fulfill the historical popular craving for magic pills and potions. Nonetheless, the pathophysiology of the various chronic diseases, especially cancer and autoimmunity, is way too complex and individual to attribute disease to someone’s behavior. It isn’t helpful, and can even be harmful (or fatal).
I say this as someone who advocates very strongly for lifestyle management approaches for chronic disease. There is no question that the dominance of ultra-processed foods in our culture is a major contributor to the dramatic increases in conditions such as metabolic syndrome, and likely key contributor to the process that triggers autoimmunity. But we shouldn’t overlook the role of the tremendous increase in substances such as drug metabolites (from other people’s drugs), industrial waste, pesticides, etc. in the water we drink and cook our food in, and that we have no control over. It’s not right to blame people for their illnesses.
Every month, we pick a published (and peer reviewed) article to highlight and discuss.
This month’s selected article
TitleUltra-processed foods and food additives in gut health and disease | AuthorsKevin Whelan, Aaron S. Bancil, James O. Lindsay, & Benoit Chassaing PublicationNature Reviews Gastroenterology & Hepatology volume, 2024. |
Is there evidence for ultra-processed foods being bad for gut health?
We think this paper is worth a read! Check it out →
With so much attention in the news and wellness websites warning about the dangers of ultra-processed food (UPFs), what is the evidence for actual badness for the gut?
This review paper highlights findings from epidemiological, preclinical (e.g. laboratory animal) and human clinical studies investigating the effects of components of ultra-processed food on measures of gut health.
Main Takeaways
Epidemiological studies (descriptive studies of groups of many people) reliably link ultra-processed food consumption with inflammatory bowel disease, colo-rectal cancer, and irritable bowel syndrome. The article does not mention it, but such studies also link “Western diet” which is made up largely of ultra-processed foods, to food allergies and celiac disease as well.
The article points out that there are also many preclinical studies showing adverse effects of food additives, such as emulsifiers, sweeteners, and colors, on aspects of gut health including gut microbes, intestinal permeability (leaky gut) and inflammation.
Unfortunately, at this time there is very little information for humans, and most studies that have addressed the issue of ultra-processed food and the gut have involved people with inflammatory bowel disease. A few such studies have shown that restricting diets to avoid ultra-processed foods can be helpful for disease management, but it is clear we need more studies with more standardized outcomes to be able to make useful specific recommendations. Apparently, there are such studies now underway, and hopefully some with a broader patient population.
The authors also point out how difficult it is to do useful research, given the wide variety of additives and processing techniques that are involved in ultra-processed food.
Taken together, this review of studies reinforces the idea that for gut health, intake of artificial ingredients, including sweeteners and emulsifiers, should be limited. But there is still a ways to go before specific recommendations can be made.
Mindful chewing for gut cramps
This month’s Pro Tip comes from me!
As a life-long sufferer of functional dyspepsia and irritable bowel syndrome, I have struggled with symptoms of cramping, bloating and slow motility. But in the last twelve years I have been doing pretty well.
What started me down the road to recovery was taking up Mindful Eating. I didn’t take up the practice to help my gut, actually. Rather, I was trying to get control of my appetite and eating habits.
Mindful Eating involves chewing food thoroughly, and paying attention to all of the tastes and textures in a food. This has the result of slowing down eating, and enabling the perceptions of “gut cues” for satiety. You learn when you have had enough. But for my stomach, this meant that the food coming down was really well chewed, and thus easier to digest. It was also coming down at a slower rate, and not so much in quantity either. Less food, better chewed! This had the rapid effect of reducing nighttime gut cramps.
Eventually I did lose weight, but the effect on gut symptoms was nearly immediate. I offer this here in case anyone with IBS/gut cramps or reflux might want to try an easy behavioral change.
Do you have a tip for us? Let us know!
Every month we will highlight an easy to make, gut-healthy dish that we are eating now!
Farmer’s Market Lasagna
It’s not very processed! The most suspicious ingredient is in the pasta sauce- “calcium chloride”.
This is a favorite for times when you have perishable ingredients, or “dibby dabs” of ingredients, that need to be used. Here are some suggested ingredients, but the key features are the no-boiling of lasagna noodles and some kind of sauce (the noodles cook in the sauce) along with the variety of vegetables. The result will be loaded with fiber-containing gut-healthy ingredients!
Ingredients
If using mushrooms or eggplant: it is best to roast them briefly first (otherwise the lasagna starts out too tall). Cut them into bite size chunks and toss with olive oil and garlic powder, and chuncks of garlic cloves if desired. Roast at 325 or 350 for 15 minutes or so, until the mushrooms shrink. If using frozen spinach: thaw and press out the extra liquid. | Steps
It is filling to eat, so this recipe will make 8-10 servings. |
Enjoy!
Our farmer’s market lasagna
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 | About the AuthorLisa E. Goehler, Ph.D. is a neuroscientist and expert in the science and treatment of psychological stress, chronic inflammation, and gut-related disorders. She pioneered the study of how GI-tract related bacteria can interact with the brain to lower mood and increase anxiety. Throughout her career, she authored over fifty publications and contributed to peer review for scientific journals and funding agencies, including the National Institute for Health. |
References
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Bascuñán, K.A.; Orosteguí, C.; Rodríguez, J.M.; Roncoroni, L.; Doneda, L.; Elli, L.; Araya, M. Heavy Metal and Rice in Gluten-Free Diets: Are They a Risk? Nutrients 2023, 15, 2975. https://doi.org/10.3390/
Chen J, Wellens J, Kalla R, Fu T, Deng M, Zhang H, Yuan S, Wang X, Theodoratou E, Li X, Satsangi J. Intake of Ultra-processed Foods Is Associated with an Increased Risk of Crohn's Disease: A Cross-sectional and Prospective Analysis of 187 154 Participants in the UK Biobank. J Crohns Colitis. 2023 Apr 19;17(4):535-552. doi: 10.1093/ecco-jcc/jjac167. PMID: 36305857; PMCID: PMC10115229.
Dicken, S.J., Jassil, F.C., Brown, A. et al. Ultraprocessed or minimally processed diets following healthy dietary guidelines on weight and cardiometabolic health: a randomized, crossover trial. Nat Med (2025). https://doi.org/10.1038/s41591-025-03842-0
Lane MM, Gamage E, Du S, Ashtree DN, McGuinness AJ, Gauci S, Baker P, Lawrence M, Rebholz CM, Srour B, Touvier M, Jacka FN, O'Neil A, Segasby T, Marx W. Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ. 2024 Feb 28;384:e077310. doi: 10.1136/bmj-2023-077310. PMID: 38418082; PMCID: PMC10899807.
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Nestares T, Martín-Masot R, Flor-Alemany M, Bonavita A, Maldonado J, Aparicio VA. Influence of Ultra-Processed Foods Consumption on Redox Status and Inflammatory Signaling in Young Celiac Patients. Nutrients. 2021 Jan 6;13(1):156. doi: 10.3390/nu13010156. PMID: 33418957; PMCID: PMC7825019.
Sarbagili-Shabat C, Zelber-Sagi S, Isakov NF, Hirsch A, Ron Y, Grinshpan LS, Anbar R, Bromberg A, Thurm T, Maharshak N. Ultra-Processed Foods Consumption Is Positively Associated with the Clinical Activity of Inflammatory Bowel Diseases: A Cross-Sectional Single-Center Study. Inflamm Intest Dis. 2024 Aug 31;9(1):241-251. doi: 10.1159/000541196. PMID: 39474331; PMCID: PMC11521535.
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