The Health Risks of Ultra-Processed Foods
By R.Davies, PhD・Nutrition
Published January 16, 2026 | 5 min read
Ultra-processed foods are associated with higher risks of obesity and many serious long-term diseases. This article summarises current evidence on the potential health harms linked to UPFs.
As UPF consumption increased globally, researchers began investigating potential health concerns associated with it. Over the past decade, the evidence has accumulated from around the world. The findings have been consistent enough to attract attention from several public health organisations and start debates about changing regulations and dietary guidelines.
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Why Are Ultra-Processed Foods Under Scrutiny?
For decades, nutrition research focused primarily on nutrients: fat, protein, carbohydrates, vitamins, and minerals. It was assumed that the health effects of food depend solely on what it is made of.
However, researchers observed that despite people consuming similar amounts of calories and nutrients had different health outcomes and body weights. They also noticed that people would naturally start to eat more of certain foods compared to others, even if they had the same amount of calories and nutrients.
So rather than focusing on just the content of the food, scientists started looking at the structure and processing methods used in different food products. This opened UPFs to scrutiny, as researchers found that people who eat a lot of UPFs tend to have poorer health [1].
Ultra-Processed Foods and Obesity
The relationship between UPF intake and body weight has received a lot of attention. Many studies find consistent links between higher UPF intake and increased risk of overweight and obesity.
This link is consistent across people of different ages and across different countries. The more UPFs that are consumed, the more fat you're likely to have. Studies have shown that when people are offered UPFs, they tend to consume more of them, about 500 calories a day more, and then go on to gain weight [2].
Ultra-Processed Foods and Heart Disease
Research consistently links higher UPF intake to increased risk of cardiovascular disease, type 2 diabetes, high blood pressure, high cholesterol and high blood sugar levels. Even those with normal body weights are still at greater risk of cardiometabolic disease with higher UPF intakes.
Ultra-Processed Foods and Cancer Risk
Some studies report associations between UPF consumption and certain cancers, particularly breast, colorectal, pancreatic and gastrointestinal cancers (cancers related to the digestive tract) [3]. Just a 10% increase in the proportion of UPFs in your diet is linked to higher cancer risk — that’s equivalent to a small UPF snack a day.
Mental Health
A recent study has linked consistent associations between higher UPF intake and increased risk of depression and anxiety [1]. This is thought to be due to increased inflammation, changes to your gut microbiome, and fluctuating blood sugar levels.
How do ultra-processed foods affect your health?
Energy Density and Calorie Intake
UPFs typically pack many calories into small volumes of food — they are “energy dense”. This high energy density makes consuming more calories easier. In other words, you can eat a lot more calories before feeling full [4].
Even when two foods have the same nutritional content: the same calories, fat, carbohydrate, salt, and sugar, people tend to eat more of the UPF than minimally processed alternatives.
Eating Rate & Food Structure
UPFs often have soft textures, which means they don't need to be chewed as much. This allows faster eating, which is associated with consuming more calories [5]. The food structure matters as well as the nutrient content.
Chewing whole foods slows eating and may trigger feelings of fullness more effectively. Processing breaks down food structure, making calories and nutrients more readily available, but potentially speeding up your natural eating pace.
“Hyperpalatability” & Reward
UPFs are designed to be highly palatable through specific combinations of fat, sugar, salt, and other strong flavourings. While there’s nothing wrong with foods tasting good, certain combinations may affect brain reward pathways in ways that encourage you to eat more of them [6].
The brain's reward system is hardwired to encourage us to eat energy-dense foods, which were scarce throughout most of human history. However, eating UPFs seems to stimulate these pathways more intensely than minimally processed alternatives.
Satiety & Hunger Signals
Eating food affects our feeling of fullness in a few ways: stomach expansion, sensing nutrients in the gut, hormonal release, and blood sugar patterns. UPFs may interact differently with these systems compared to whole foods.
Some UPFs are digested rapidly, causing quick rises and falls in blood sugar that can trigger renewed hunger and cravings. Other UPFs may not trigger satiety hormones as effectively as whole foods, even when providing the same amount of calories.
Your Microbiome
The gut microbiome influences many other systems around the body: your metabolism, inflammation, and potentially even your mood and behaviour. Some studies suggest that emulsifiers and other additives common in UPFs may negatively affect your gut and the bacteria in it.
Displacement of Nutritious Foods
A simpler, but overlooked cause, also deserves a mention. If UPFs take up a large portion of your diet, they replace other (healthier) foods. Even if UPFs weren’t actively harmful, if they go on to replace fruits, vegetables, legumes, and other whole foods, this means you’ll miss the beneficial nutrients contained within them.
Frequently Asked Questions
What are examples of ultra-processed foods?
Ultra-processed foods are industrial products containing ingredients rarely found in home cooking. They contain ingredients like emulsifiers, artificial flavours, sweeteners, and preservatives.
Common examples: packaged snacks (crisps, biscuits), soft drinks, fast food, mass-produced bread and cereals, ready meals, processed meat (sausages, nuggets), and most flavoured yoghurts. The "NOVA" classification is the standard for identifying them.
How much ultra-processed food is safe to eat?
Research has not identified a completely safe threshold. Research shows that the more UPFs consumed, the greater the health risks, so even low consumption carries a lower risk. Most experts recommend keeping UPFs to a minimum; the lower the better.
Do ultra-processed foods cause cancer?
Associations between high UPF intake and several cancers, particularly breast, colorectal, and pancreatic cancer. These are speculated to be caused by food additives, packaging contaminants, and the displacement of (healthier) protective whole foods in your diet.
Why are ultra-processed foods bad for you?
The harms come from many places: UPFs displace nutritious whole foods; they are designed to be hyperpalatable, causing overconsumption (studies show people eat around 500 more calories daily when offered UPFs). They contain additives, which damage your gut microbiome and hormones, and cause inflammation. The degree of processing itself appears to cause harm beyond the nutrient profile.
What is the NOVA food classification system?
NOVA classifies foods into four groups by processing level:
- Group 1 ("unprocessed foods", e.g. vegetables, eggs, meat)
- Group 2 ("culinary ingredients", e.g. oils, flour, salt)
- Group 3 ("processed foods", e.g. cheese, canned legumes)
- Group 4 ("ultra-processed" — industrial formulations with multiple additives).
It is the most widely used framework in ultra-processed food research.
Key Takeaways
The evidence linking UPFs to various health outcomes has accumulated substantially over the past decade. However, there are still questions that remain unanswered. Which UPFs or processing methods are influencing health? Do UPFs interact with other dietary, lifestyle, or personal circumstances? Is there a “safe” amount of UPFs you can eat? Can exercise offset UPF intake? Can a better diet counteract eating some UPFs?
The research will continue. Guidelines and regulations may evolve (as they have already in many countries). But in the meantime, the evidence suggests that keeping UPF intake to a minimum, where practical, and in most cases, replacing them with whole foods, is advisable. This doesn't necessarily mean eliminating all UPFs or feeling guilty about realistic food choices. It does suggest that reducing reliance on these products, when feasible, likely supports better health prospects.
Sources
1. Lane MM et al. Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses. BMJ. 2024 Feb 28;384:e077310. PMID: 38418082
2. Hall KD et al. Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metab. 2019 Jul 2;30(1):67-77.e3. PMID: 31105044
3. Isaksen IM, Dankel SN. Ultra-processed food consumption and cancer risk: A systematic review and meta-analysis. Clin Nutr. 2023 Jun;42(6):919-928. PMID: 37087831
4. Srour B et al. Ultra-processed food intake and risk of cardiovascular disease: prospective cohort study (NutriNet-Santé). BMJ. 2019 May 29;365:l1451. PMID: 31142457
5. Galdino-Silva MB et al. A Meal with Ultra-Processed Foods Leads to a Faster Rate of Intake and to a Lesser Decrease in the Capacity to Eat When Compared to a Similar, Matched Meal Without Ultra-Processed Foods. Nutrients. 2024 Dec 21;16(24):4398. PMID: 39771019
6. de Macedo IC et al. The Influence of Palatable Diets in Reward System Activation: A Mini Review. Adv Pharmacol Sci. 2016;2016:7238679. PMID: 27087806
Published: January 16, 2026
Lead Author: R.Davies, PhD | Author Bio
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