American Heart Association released a science advisory earlier this month that highlighted the impact of ultra-processed foods on cardiometabolic health.Mario Anzuoni/Reuters
Ultra-processed foods are a growing concern due to increasing consumption worldwide and their connection to numerous adverse health effects.
It’s estimated that Canadian adults, for example, consume nearly half of their daily calories from these foods, while the diets of young children and teenagers contain even more.
Despite a wealth of evidence that strongly suggests high intakes of ultra-processed foods, or UPFs, are harmful, unknowns still exist that hinder the development of clear and actionable dietary advice.
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Earlier this month, the American Heart Association released a science advisory highlighting the impact of UPFs on cardiometabolic health, as well as future research priorities to fill in those knowledge gaps.
The advisory also outlined an approach to guide dietary choices by categorizing UPFs as “least healthy,” “moderately healthy” and “healthier.”
Here’s a breakdown of the association’s new science advisory, its list of “healthier” UPFs, plus the worst UPFs, which are important to limit.
How are UPFs defined?
UPFs are industrial formations that contain additives to enhance shelf-life, appearance, flavour and texture, ingredients not found in home kitchens.
Examples include soft drinks, processed meats, packaged snacks, mass-produced breads and baked goods, ready-to-heat meals (e.g., frozen pizza, chicken nuggets), refined breakfast cereals, protein bars, margarine and many, many more.
A number of systems have been developed to categorize foods based on their level of processing.
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The most widely used, and the focus of the American Heart Association’s advisory, is the NOVA system. It categorizes foods from group 1 (least processed) to group 4 (ultra-processed).
A shortcoming of the NOVA system, however, is that there isn’t a breakdown of the nutritional quality of the foods in each category. Some UPFs may still provide important nutrients despite containing ultra-processed ingredients.
According to the AHA science advisory, published Aug. 8 in the journal Circulation, this limitation underscores the need for distinctions between UPFs rather than blanket recommendations to avoid all of them.
Cardiometabolic health risks of UPFs
Meta-analyses of studies have found that as the intake of UPFs increases, so does the risk of cardiovascular disease, Type 2 diabetes, obesity and overall mortality. (A meta-analysis combines the results of many studies to reach an overall conclusion.)
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A 2024 review of 45 meta-analyses classified the evidence as convincing for death from cardiovascular disease and highly suggestive for diabetes and obesity. A high intake of UPFs (versus low) was linked to a 25 to 58 per cent increased likelihood of cardiometabolic health problems and a 21-per-cent to 66-per-cent greater risk of mortality.
A 2025 study commissioned by the Heart and Stroke Foundation of Canada estimated that 37 per cent of cases of heart disease and stroke, and 38 per cent of deaths, could be attributed to the consumption if UPFs.
How UPFs can harm health
Most UPFs are high in saturated fat, added sugars and sodium, ingredients known to be harmful when consumed in excess. A diet high in UPFs can also supply excessive calories.
Emerging evidence also suggests that, beyond their poor nutrient profiles, the processing of UPFs itself plays a role in the health risks associated with diets high in UPFs.
The removal of fibre in UPFs can lead to blood glucose and insulin spikes, which can trigger hunger.
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As well, UPFs often contain specific combinations of fat, sugar and sodium, as well as additives and textures, that may stimulate the brain’s reward system making them highly appealing and easy to overeat.
Additives such as certain emulsifiers and artificial sweeteners may also disrupt the gut microbiome.
More research is needed to determine if the processing of UPFs and their additives are harmful independent of poor nutrient quality.
AHA: a framework to approach UPFs
According to the new science advisory, not all UPFs have poor nutritional quality. The association considers some “heathier” than others because they have better nutritional profiles.
But this is a very small list of foods. It includes low-sodium whole grain breads and crackers, lightly or unsweetened high fibre breakfast cereals and plant-based meat and dairy alternatives that are low in sodium, added sugars and saturated fat such as soy milk, tofu and tempeh.
Findings from a randomized controlled trial from the United Kingdom, published August 4, suggests that eating a diet containing “healthier” UPFs lower in salt, sugar and saturated fat can still result in people eating more calories than they would if eating a minimally processed diet.
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As researchers continue to learn the specific ways in which UPFs influence health, the AHA urges people to cut back on the most harmful UPFs, ones that are high in sodium, added sugars and saturated fat, as well as calories.
Some of these include processed meats, sugar-sweetened drinks, processed cheese, candies, gummy fruit snacks, ice cream, refined “white” breads and tortillas, instant noodles, boxed macaroni and cheese and canned fruit in syrup.
It’s impossible to completely avoid UPFs. The goal is to limit their consumption.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on X @LeslieBeckRD
