Extra-butter popcorn at the movie theater, hot dogs at a baseball game, and cotton candy at the state fair. These are all examples of how ultra-processed foods (UPF) are part of our culture. So are sneakier ones, like store-bought blueberry muffins and toaster pastries. But what happens when these occasional treats become everyday habits?
Overeating UPF can lower the nutritional quality of your diet. They tend to be high in calories, fat, and salt, but low in helpful nutrients [1]. Let’s dive into what’s considered an ultra-processed food and how the added ingredients impact the beneficial microorganisms living in your gut and your overall health.
What is ultra-processed food?
When you shop at the grocery store, the foods on the shelves have taken very different paths to get there. You might see strawberries placed directly into their containers by field workers, and just an aisle over, you’ll find carbonated soft drinks made in industrial facilities. These foods fall along a spectrum from fresh to ultra-processed, and experts typically sort them into four main categories, known as the NOVA classification system [2]:
- Unprocessed and minimally processed foods are fresh foods such as eggs, whole fruit and vegetables, and fresh meat. They may be washed, peeled, sliced, or dried, but generally do not contain any additional ingredients.
- Processed culinary ingredients include salt, sugar, simple oils, honey, and vinegar. While they may be pressed, refined, ground, or dried, they’re generally pure ingredients.
- Processed foods include canned and frozen vegetables, cheese, and cured meats such as ham and bacon. Some are baked, smoked, or fermented. Others are canned or have added salt. But typically, these foods retain their original identity.
- Ultra-processed foods contain little to no intact whole foods and are primarily made of refined ingredients and additives that enhance flavor and prolong shelf life. They generally have more added sugar, total fats, saturated fats, and less fiber, protein, vitamins, and minerals [1].
The Standard American Diet (SAD) leans heavily on processed foods. UPFs make up between 58-80% of calories consumed in the U.S. and nearly 90% of added sugars [1], [3].
How to avoid ultra-processed foods: everyday items to watch
When you think about UPFs, the following probably come to mind:
- Sodas and flavored drinks (the most consumed UPF in the US and Canada) [1]
- Fast food (burgers, fries, chicken nuggets)
- Prepared meals (instant noodles, frozen meals)
- Sugary cereals
- Packaged snacks
- Candy
But these are also UPFs because they contain additives:
- Mass-produced bread
- Packaged pastries
- Hot dogs and sausages
Common ingredients in ultra-processed foods
Most of us eat processed foods now and then. Think canned beans, frozen vegetables, or pasta sauce with a bit of added salt or sugar to help preserve it. They are considered processed, but in a simple, straightforward way.
Ultra-processed foods, or UPFs, are a different story. They often have long ingredient lists filled with items you might not recognize or keep in your kitchen. If you’re checking the label, keep three things in mind:
- Just because a food has a lot of ingredients does not necessarily mean it’s unhealthy. A homemade granola bar might have a dozen ingredients like oats, nuts, seeds, dried fruit, and spices, but these are all minimally processed and nutrient-dense.
- An unfamiliar or “chemical-sounding” ingredient is not necessarily bad (e.g., riboflavin is a type of vitamin B).
- How much you eat matters. Many ingredients are safe in small amounts, but unhealthy in large quantities.
The purpose of additives in ultra-processed foods is to make them look and taste better (loaded with flavors and/or colors), extend their shelf life, and for convenience on the go. These ingredients include:
Sugars and sweeteners
- High-fructose corn syrup
- Glucose syrup
- Artificial sweeteners (aspartame, sucralose, etc.)
Fats and oils
- Hydrogenated oils and trans fats
- Palm oil, soybean oil, and canola oil
Starches and thickeners
- Modified starches
- Maltodextrin
- Guar gum
- Xanthan gum
Other additives
- Emulsifiers (CMC, carrageenan, lecithins)
- Preservatives (sodium benzoate, potassium sorbate, nitrites)
- Artificial colors (allura red, tartrazine)
- Whitening agents (titanium dioxide)
- Flavor enhancers (monosodium glutamate/MSG)
How ultra-processed foods impact your health
Chances are, you’ve grabbed a packaged snack or quick meal on a busy day; it’s part of modern life. Things get tricky when ultra-processed foods edge out the whole, nutrient-rich foods our bodies need.
A 2019 study that followed U.S. adults for about 20 years found that those who frequently ate ultra-processed foods had a 31% higher risk of death from any cause [4]. And the findings don’t stop there. Researchers are uncovering more ways ultra-processed food can affect our health, from how we feel each day to long-term conditions.
Chronic diseases and mental health
Eating more ultra-processed food is linked to a higher risk of chronic diseases like diabetes and obesity. There’s also a connection to mental health issues, such as depression [5]. For people with existing conditions, like ulcerative colitis (UC), UPF has been linked to more frequent flare-ups, especially in men [6].
Body Mass Index (BMI)
People who get most of their calories from UPF have a higher BMI, larger waistlines, and a greater risk of being overweight or obese; this link was stronger in women [7].
Inflammation
UPFs have been linked to increased inflammation, which can affect everything from your immune system to your energy levels. This might be due to both the overall quality of the diet and how these foods are processed [8].
Gut microbiome
In a large group of adults with metabolic syndrome who were also overweight or obese, eating more UPF was linked to higher calorie intake as well as shifts in the gut microbiome. They had higher amounts of Alloprevotella, Negativibacillus, Prevotella, and Sutterella, which are generally unfriendly and associated with metabolic disorders [9].
Appetite
Leptin is a hormone that helps your brain know when you’ve had enough to eat. But eating a lot of ultra-processed food may be tied to leptin resistance, making it harder for the brain to get the signal that you’re full [10]. This can make you feel hungry and overeat, even when your body has enough stored energy. It’s one way that UPF may interfere with how your gut and brain communicate.
Allergies
In children, eating common UPF ingredients (fructose, sugary and carbonated drinks, MSG, and high-carbohydrate UPFs) has been linked to an increased risk of asthma, allergic rhinitis (hay fever), wheezing, food allergies, and atopic dermatitis (eczema). There’s also evidence linking some commercial baby foods to a higher prevalence of food allergies, but more research is needed [11].
How do UPF ingredients impact your gut microbiome?
We’ve talked about how ultra-processed foods can affect your overall health, but what about the tiny organisms living in your gut? Scientists are now digging into how specific ingredients in these foods might impact the gut. By getting to know what’s actually in your snacks and meals, you can make more informed choices that support your gut and overall well-being.
Preservatives
Have you ever noticed how store-bought bread can last a week or two on the counter, while a freshly baked loaf may go bad after a few days? That’s preservatives at work.
Food preservatives help keep food safe by preventing spoilage, and most are considered safe to eat. But some may also affect the balance of microbes in your gut. In lab studies (not human trials), the preservatives sodium bisulfite, sodium sulfite, sodium benzoate, sodium nitrite, and potassium sorbate reduced beneficial gut bacteria including Lactobacillus casei, Lactobacillus plantarum, Lactobacillus rhamnosus, Streptococcus thermophilus, Clostridium tyrobutyricum, Lactobacillus paracasei, Bifidobacterium longum, and Bacteroides coprocola [12], [13].
Salt
While a small amount of salt is essential in our diet, eating a lot of salt can cause problems. High salt consumption may reduce the amount of beneficial Lactobacillus in the gut, increase inflammatory cells, and raise blood pressure [14]. Many UPFs contain high levels of salt.
Artificial sweeteners
If you’ve ever swapped sugar for a zero-calorie sweetener in your coffee or favorite snack, you’re not alone. Artificial sweeteners are everywhere, and while they may seem like a guilt-free alternative, researchers are starting to uncover how they might influence your gut microbiome.
Scientists have found evidence that synthetic sweeteners like sucralose and saccharin can disrupt microbial balance [15], [16]. On the flip side, natural sweeteners like monk fruit and tagatose may have neutral or even beneficial effects [17], [18].
Artificial colors
Brightly colored snacks, cereals, and drinks often owe their eye-catching hues to artificial dyes. While these colors can make food look more fun, some research suggests they may also be influencing gut health in ways we’re only beginning to understand.
Allura Red (also known as Red Dye 40) has been shown to make gut inflammation worse in mice, especially with long-term or early-life exposure [19]. The gut microbiome may play a role in this effect. Other dyes like Tartrazine and Sunset Yellow have been linked to changes in bacterial growth in lab settings [20].
Emulsifiers
Emulsifiers are used in UPFs to improve texture, prevent separation, and extend shelf-life. You might spot them in frozen desserts, spreadable cheese, bottled sauces, and salad dressings.
Sodium carboxymethyl cellulose (CMC), polysorbate-80 (P80), and carrageenan are linked to negative effects on the gut microbiome, like increased inflammation, a weaker gut barrier, and shifts in bacterial abundance [21], [22], [23].
Titanium dioxide (TiO2)
Also known as E171, Titanium dioxide is a whitening agent used to improve the appearance of foods, like artificial dyes. You often see it listed in flour, creamers, and candies.
Evidence from studies in pregnant mice shows that consuming TiO₂ can alter their offspring’s gut microbiome and raise the risk of colitis and IBD later in life [24]. Another study showed that mice with IBD had worsened symptoms after consuming TiO2. This chemical was also found in the spleens and blood of people with active ulcerative colitis, suggesting it may build up in the body and cause problems, especially if you already have gut issues [25].
While TiO2 may not impact the composition of your gut microbiome, it may change the behavior of those microorganisms in a way that can affect your overall health [26].
How to look out for your gut in a UPF world
Ultra-processed foods are often convenient, cheap, and (let’s face it) delicious, making them hard to avoid. However, growing research shows that many of their additives have a bigger impact than simply enhancing flavor and shelf life. No need to give them up entirely — just knowing how they impact your body and gut can help you make more informed decisions.
Having an occasional treat isn’t going to ruin your health. But making whole foods the base of your diet is one of the best things you can do for your gut. We get that it’s not always easy. Fresh, minimally processed foods aren’t always available or affordable. The upside? Frozen and canned fruits and veggies can be just as nutritious as fresh, and they’re often more budget-friendly and easier to keep in your pantry [27].
Your gut microbiome thrives on the fiber and nutrients in whole foods. A Tiny+ Family Membership gives you personalized recommendations so you can better support your loved ones' needs through everyday choices.
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