Eating more ultra-processed foods may be linked to a higher risk of heart disease, diabetes, cancer, mental health conditions, digestive illnesses and early death, according to a major review of international research.

The study, published in Family Medicine and Community Health, combined findings from 51 long-term studies involving almost nine million adults. Researchers followed participants for between two and 32 years, comparing people who ate the most ultra-processed foods with those who ate the least.

The results showed a clear pattern: higher intake of ultra-processed foods, often shortened to UPFs, was associated with poorer health outcomes across several major disease categories.

The research does not establish that these foods directly cause disease. It does show a consistent association. The more ultra-processed food people consumed, the greater the observed health risks became.

“For every additional 100 grams of ultra-processed food consumed daily, cardiovascular event risk rose by 14%. Cancer risk increased by 4%. The risk of death from any cause increased by 3%”

That pattern is known as a dose-response relationship. It means that risk appeared to rise as UPFs made up a larger share of the diet.

Ultra-processed foods are more than ordinary foods that have been frozen, canned, cooked or packaged. They are usually industrial products made with multiple ingredients, including additives that are not commonly used in home kitchens.

The NOVA food-classification system, widely used in nutrition research, describes UPFs as industrial formulations often containing five or more ingredients. They may include flavourings, colourings, emulsifiers, sweeteners, preservatives and substances designed to improve texture, appearance or shelf life.

Examples include sugary drinks, confectionery, packaged crisps and snacks, instant noodles, many ready meals, fast food, processed meats, sweetened breakfast cereals and some commercially produced baked goods.

These products are often high in added sugar, salt, saturated fat and refined carbohydrates. They may also contain relatively little fibre, protein, vitamins and minerals. Their intense flavours, soft textures and convenience can make them easy to eat in large amounts.

The researchers examined a wide range of health outcomes. People with the highest UPF intake had a 24% higher risk of cardiovascular events, including heart attacks and strokes, compared with those who ate the least.

Their risk of overweight or obesity was 23% higher. The risk of metabolic syndrome or diabetes was 24% higher.

Metabolic syndrome is a cluster of risk factors that can include raised blood sugar, high blood pressure, abnormal cholesterol levels and excess fat around the waist. It increases the chance of developing cardiovascular disease, stroke and type 2 diabetes.

The review also found a 27% higher risk of depression and anxiety among those with the highest ultra-processed food consumption. Digestive disease risk was 31% higher, including inflammatory bowel conditions such as Crohn’s disease.

Cancer risk was 12% higher. The risk of death from any cause was 18% higher.

These figures are relative risks. They do not mean that a person who eats a packaged snack will inevitably become ill. Health is shaped by many factors, including smoking, alcohol consumption, sleep, exercise, genetics, income, stress, medical care and the quality of the whole diet.

Even so, the large number of participants and the long follow-up periods strengthen the relevance of the findings. The researchers also tested whether risk changed with specific increases in UPF intake.

For every additional 100 grams of ultra-processed food consumed daily, cardiovascular event risk rose by 14%. Cancer risk increased by 4%. The risk of death from any cause increased by 3%.

The risk of metabolic syndrome or diabetes rose by 2% for every extra 100 grams consumed each day. A 10% increase in the share of UPFs in the diet was associated with a 16% higher risk of metabolic syndrome or diabetes.

The association with high blood pressure was less certain. The general comparison between high and low consumers did not show a statistically significant link. However, the dose-response analysis suggested that every additional 100 grams of UPFs each day was associated with an 11% higher risk of high blood pressure.

Nutrition researchers say the findings should be interpreted carefully. The included studies were observational. They tracked people’s diets and health over time, yet they cannot fully prove cause and effect.

Dietary information was also collected using questionnaires, 24-hour food recalls and dietary histories. These tools rely on people accurately remembering what they ate. Some participants may under-report snacks, drinks or takeaways.

Researchers attempt to account for other factors, such as age, smoking, body weight and physical activity. Still, no study can completely remove every influence that may affect the results.

There are several reasons why diets rich in UPFs may be associated with worse health. One is their usual nutritional profile. Frequent consumption can crowd out foods associated with good health, such as vegetables, fruit, pulses, wholegrains, nuts, seeds and minimally processed protein sources.

Low-fibre diets can affect bowel health, appetite control and blood sugar regulation. Diets high in salt may contribute to raised blood pressure. Added sugars and refined starches can lead to sharp rises in blood glucose, particularly when eaten frequently.

Ultra-processed foods are often energy-dense, meaning they provide a lot of calories in a small serving. They may be eaten quickly and may not produce the same feeling of fullness as meals based on fibre-rich whole foods.

Scientists are also investigating whether aspects of industrial food production might play a role. Possible areas of interest include additives, changes in food texture, compounds created during manufacturing and chemicals that can migrate from packaging. Evidence on these issues is still developing.

Importantly, not every food labelled ultra-processed has the same nutritional value.

A sugary fizzy drink and a packaged high-fibre wholegrain loaf may both be classified as UPFs under NOVA. They are not nutritionally comparable. A high-fibre bread may help people meet wholegrain and fibre targets, especially where fresh bakery products are less available or less affordable.

Processing itself is not always a problem. Frozen vegetables, canned beans, pasteurised milk and tinned fish are processed foods. They can be safe, nutritious, affordable and practical.

The concern centres on eating patterns dominated by heavily formulated products that are typically low in fibre and rich in ingredients linked with poorer health when consumed in excess.

Experts generally do not recommend trying to eliminate every UPF overnight. For many people, that approach is unrealistic. Cost, long working hours, limited kitchen facilities, childcare responsibilities and food availability can all shape daily decisions.

A more manageable approach is to gradually make whole and minimally processed foods the basis of meals. Small changes can add up.

Replacing sugary drinks with water, milk or unsweetened drinks is one option. Choosing fruit, yoghurt, nuts or plain popcorn instead of sweets and crisps can reduce intake of added sugar, salt and less healthy fats.

Simple home-cooked meals can also help. They do not need to be complicated. Porridge with fruit, eggs on wholegrain toast, vegetable soup, bean chilli, lentil curry, stir-fries, omelettes and baked potatoes with fillings can all be made with straightforward ingredients.

Cooking at home gives people greater control over the amount of salt, sugar and fat in their food. It may also make it easier to include vegetables, beans and wholegrains.

Fast food can be reduced gradually rather than abandoned completely. When eating out, smaller portions, water instead of sugary drinks and meals that include vegetables or pulses can be sensible choices. Adding a salad or fruit side may help balance a meal that is otherwise heavily processed.

Food labels can offer useful clues. Long ingredient lists, multiple additives, high sugar and salt levels, and strong claims about convenience or intense flavour can indicate that a product is highly processed. Comparing similar products can help shoppers choose options with more fibre and less salt, saturated fat or added sugar.

The central message from the review is not that every packaged food is harmful. It is that the overall balance of the diet appears to matter greatly.

Ultra-processed foods can fit into ordinary life. They are convenient, widely available and sometimes inexpensive. Problems may arise when they become the foundation of everyday eating.

Many chronic conditions occur together. Obesity, high blood pressure, diabetes and heart disease can affect the same person at the same time. Mental health conditions may also accompany physical illness. This combination, known as multimorbidity, can make treatment more difficult and place additional pressure on health services.

Reducing UPF intake may therefore support health in several ways at once. The most practical aim is not perfection. It is to eat more food that resembles its original ingredients, and to rely less often on products designed primarily for convenience, prolonged shelf life and highly appealing taste.