Introduction,
It’s a familiar scene: you grab a quick snack, perhaps a bag of chips or a protein bar, maybe a soda to wash it down. In a busy world, ultra-processed foods (UPFs) have become the go-to for millions, offering convenience and affordability. But as researchers continue to uncover the health implications of these foods, it’s becoming clear that the convenience may come at a much higher cost.
UPFs, which include products like chips, sodas, instant noodles, and even most types of packaged bread, are engineered to last on shelves, taste great, and appeal to consumers on the go. But beyond the familiar packaging and flavours, these foods often contain a cocktail of additives, preservatives, and artificial flavours, while being low in nutrients like fibre and protein. This combination has been linked to a concerning range of health issues, including obesity, diabetes, heart disease, cancer, and even mental health conditions like depression.
The Rise of Ultra-Processed Foods and the Health Risks
Over the last few decades, diets have shifted drastically in favour of convenience foods. The trend is not just in the U.S.; it’s a global phenomenon. In the 1980s and 1990s, as globalization sped up food production and distribution, a wave of prepackaged, mass-produced foods flooded markets around the world. In Brazil, for instance, nutritional epidemiologist Carlos Monteiro observed a sharp rise in ultra-processed foods and a corresponding increase in chronic diseases.
According to a study he conducted with his colleagues, traditional diets high in whole foods like rice and beans were replaced by processed and packaged foods like cookies, sodas, and instant noodles. Monteiro later coined the term "ultra-processed foods" to describe these products, which are chemically altered in ways that make them almost unrecognizable from their original forms.
UPFs have become a significant part of the American diet, with some studies suggesting they make up around 60% of the average American’s calorie intake, and an even higher proportion among children. These foods tend to be calorie-dense, high in sugar and unhealthy fats, and engineered to be easy to overeat, which may help explain why their consumption is linked to rising rates of obesity, diabetes, and high blood pressure. But the potential harm goes beyond metabolic diseases; studies have found links between UPFs and mental health issues, inflammatory diseases, and autoimmune disorders.
Understanding What Makes UPFs Harmful
While many foods are technically “processed” in some way, not all processed foods are created equal. At one end of the spectrum, we have basic processing techniques like cooking or canning, which preserve nutrients while making foods safe and accessible. A steamed vegetable, for example, still retains much of its original nutritional value. At the other end of the spectrum, however, are ultra-processed foods, which are fundamentally different from whole foods and minimally processed options.
UPFs are products of heavy industrial processing. Take corn, for example, a common starting ingredient. Through a series of chemical processes, corn can be broken down into various components, corn syrup, corn oil, corn fibre, and cornstarch. These individual components are then recombined with other ingredients and numerous additives to create shelf-stable, hyper-palatable products. Artificial flavours, colourings, foaming agents, and emulsifiers are added to improve taste and texture, and often vitamins and minerals are reintroduced to replace nutrients lost during processing.
These additives, along with the high levels of sugar, fat, and salt in UPFs, may contribute to their adverse health effects. For example, research suggests that the additives and altered nutrient composition of UPFs may lead to changes in the gut microbiome, increasing the risk of inflammation and weakening the immune system. Additionally, UPFs tend to be low in fibre and protein, two nutrients that help with satiety, making it easy to overconsume these foods and difficult to feel full.
The Link Between UPFs and Chronic Disease
Numerous studies over the past decade have documented the relationship between UPF consumption and chronic disease. A study conducted in 2022 following nearly 200,000 adults in the UK found that every 10% increase in UPF consumption was associated with a 6% increased risk of death from cancer, including a 16% increase in breast cancer mortality and a 30% rise in ovarian cancer mortality. Other research has linked UPFs with an increased risk of cardiovascular disease, depression, and inflammatory bowel diseases like Crohn’s disease.
The exact mechanisms are still being studied, but several theories are emerging. One is that UPFs may trigger addictive-like responses in the brain. The combination of sugar, salt, fat, and certain additives in UPFs has been shown to activate reward centres in the brain, similar to how addictive substances affect the brain. This hyper-palatable profile makes it easy to eat more than intended, and over time, this pattern of overconsumption can lead to metabolic and cardiovascular problems.
Another theory is that the lack of fibre and other essential nutrients in UPFs may contribute to inflammation. Fiber is crucial for feeding beneficial gut bacteria, which play a significant role in immune and metabolic health. Without fibre, gut bacteria diversity may decline, leading to an increase in inflammation, a condition linked to numerous diseases, including Alzheimer’s, diabetes, and depression.
The Accessibility Challenge, Why UPFs Are Hard to Avoid
While cutting back on UPFs could theoretically improve health, actually doing so is easier said than done. UPFs are often far more affordable and accessible than whole or minimally processed foods. According to a study by the U.S. Department of Agriculture, a calorie from an ultra-processed food like chips or candy costs significantly less than a calorie from fresh vegetables or lean proteins. For low-income families and those in food deserts, where grocery options are limited, UPFs can sometimes be the only realistic option.
Public health advocates argue that our food environment needs a complete overhaul to make healthy choices feasible for everyone. “If we want people to eat healthier, we need to ensure that healthy foods are not only available but also affordable,” says Dr. Chris van Tulleken, an infectious disease physician and author of Ultra-Processed People. He points out that many UPFs are marketed as healthy or convenient, with labels that can be misleading. Van Tulleken suggests that regulatory changes could include clearer labelling on UPF packaging and policies to limit advertising targeted at children.
Moving Toward a Healthier Food Landscape
With mounting evidence against UPFs, some countries are beginning to take action. Brazil, for example, has implemented national dietary guidelines that discourage the consumption of UPFs, while promoting meals made from whole foods. France has introduced front-of-package labelling systems to help consumers make healthier choices, and several European countries are discussing taxes on sugary drinks and other UPFs.
In the U.S., efforts are gaining traction, but there is still a long way to go. School lunch programs, often laden with UPFs, are a prime target for reform. Policies that subsidize fresh produce and other whole foods, while taxing UPFs, could shift the balance, making healthier options more accessible. Additionally, expanding access to nutrition education and incentivizing local food production could help communities reduce their reliance on ultra-processed options.
Making Healthier Choices in a UPF-Dominated World
For individuals looking to cut back on UPFs, small changes can make a big difference. Dr. van Tulleken suggests starting by focusing on single-ingredient foods whenever possible, like fresh fruits, vegetables, whole grains, and lean proteins. These foods are rich in nutrients, free from additives, and naturally satisfying.
Reading ingredient labels is another simple step. As van Tulleken points out, “If it has ingredients you wouldn’t normally find in a home kitchen, it’s probably ultra-processed.” By slowly replacing UPFs with whole foods, individuals can reduce their exposure to potentially harmful additives while increasing their intake of fibre and essential nutrients.
The research on UPFs is ongoing, and while there’s more to learn, the existing evidence strongly suggests that a diet high in UPFs is detrimental to long-term health. As scientists, policymakers, and consumers continue to grapple with the complexities of food processing, one thing remains clear: prioritizing whole, minimally processed foods is a powerful step toward better health.
References
- Monteiro, C. A., et al. “Ultra-Processed Foods: A Conceptual Analysis.” Public Health Nutrition, 2018.
- Juul, F., et al. “The Impact of Ultra-Processed Foods on Chronic Disease.” Nutritional Epidemiology, 2021.
- Hall, K. D., et al. “Ultra-Processed Foods and Health Outcomes.” American Journal of Clinical Nutrition, 2022.
- van Tulleken, C. Ultra-Processed People: Why We Eat Stuff That Isn’t Food—And How We Can Change It. HarperCollins, 2023.