What does the evidence actually show about ultra-processed foods and health?
The bulk of the evidence points to a clear, consistent link between higher consumption of ultra-processed foods and worse health outcomes. A 2023 systematic review and meta-analysis of 11 studies (including three large prospective cohorts) found that a 10% increase in the proportion of UPFs in the diet was associated with a 13% higher risk of overall cancer and an 11% higher risk of breast cancer [1]. High intake was also linked to a 30% higher risk of colorectal cancer and a 49% higher risk of pancreatic cancer [1]. These associations held even after adjusting for obesity and total calorie intake, suggesting the effect goes beyond just overeating.
A 2025 Lancet Series, which combined multiple meta-analyses and over 100 prospective studies, concluded that the displacement of whole-food diets by UPFs is a key driver of the global rise in diet-related chronic diseases, including type 2 diabetes, cardiovascular disease, and cancer [5]. The series also identified multiple mechanisms beyond nutrient content, such as hyper-palatability, soft texture promoting overeating, and the presence of additives and endocrine disruptors [5].
However, the evidence is not without debate. A 2022 commentary argues that the NOVA classification system (which defines UPFs) is poorly defined and that the health effects of UPFs can be fully explained by conventional factors like energy density, added sugar, and low fiber [3]. This perspective holds that existing nutrient profiling systems are sufficient and that labeling some nutrient-dense processed foods (e.g., some breakfast cereals) as unhealthy is counterproductive [3].
Are all ultra-processed foods equally bad? The evidence says no.
A key nuance emerging from recent research is that the health impact of UPFs varies dramatically by food subgroup. A 2024 analysis of the large European Prospective Investigation into Cancer and Nutrition (EPIC) cohort found that while overall UPF consumption increased type 2 diabetes risk, increasing intake of specific UPF subgroups—such as breads, biscuits, and breakfast cereals—at the expense of non-UPFs actually reduced diabetes risk [4]. This directly challenges the idea that all UPFs should be lumped together in dietary guidance.
Proponents of the NOVA classification counter that these subgroup findings are unreliable due to very low consumption levels of some foods (e.g., ultra-processed plant-based alternatives made up only 0.1% of total food intake) and the risk of false-positive results from multiple comparisons [4]. They argue that guidance should focus on the totality of evidence across 32 ill-health outcomes, not just diabetes [4]. Still, the finding that some UPFs may be neutral or even beneficial in specific contexts is a real tension that public health guidance must address.
How is this evidence already shaping dietary guidelines worldwide?
Despite the academic debate, the concept of food processing is already influencing dietary guidelines globally, though unevenly. A 2022 analysis of 106 national dietary guidelines found that 99% used nutrient-based messages (e.g., 'limit salt, sugar, fat'), but only 45% of 'eat less' messages explicitly referenced food processing [2]. However, 53% of the specific foods discouraged in these guidelines were ultra-processed, indicating that processing is implicitly targeted even when not named [2].
The same analysis found tensions between nutrient-based and processing-based advice: some minimally processed foods (e.g., fruit juice) were discouraged due to sugar content, while some UPFs (e.g., certain breakfast cereals) were not flagged [2]. This suggests that as guidelines evolve to include processing, they must carefully define terms and consider consumer understanding. The authors note that simply telling people to 'avoid ultra-processed foods' may be confusing without clear, actionable examples [2].
About These Sources
This answer is built on 5 peer-reviewed studies — published from 2022 to 2025, 2 from 2024 or later, 5 in Q1 journals, collectively cited 306 times — selected as the most relevant from 5 studies that passed quality screening, drawn from 49 papers retrieved from a database of over 500 million.
Sources used in this answer
Ultra-processed food consumption and cancer risk: A systematic review and meta-analysis
A 2023 systematic review and meta-analysis of 11 studies found that a 10% increase in UPF intake was associated with a 13% higher risk of overall cancer and a 49% higher risk of pancreatic cancer, with consistent positive associations for colorectal and breast cancer.
Representations of Ultra-Processed Foods: A Global Analysis of How Dietary Guidelines Refer to Levels of Food Processing
A 2022 analysis of 106 national dietary guidelines found that 99% used nutrient-based messages, while only 45% explicitly referenced food processing; 53% of discouraged foods were ultra-processed.
Does the concept of “ultra-processed foods” help inform dietary guidelines, beyond conventional classification systems? NO
A 2022 commentary argues that the NOVA classification is poorly defined and that the health effects of UPFs can be fully explained by conventional nutrient factors, adding little to existing nutrient profiling systems.
Are all ultra-processed foods bad for health?
A 2024 analysis of the EPIC cohort found that while overall UPF intake increased type 2 diabetes risk, some UPF subgroups (e.g., breads, breakfast cereals) were associated with reduced risk, questioning the use of a single UPF metric for guidance.
Ultra-processed foods and human health: the main thesis and the evidence
A 2025 Lancet Series combining over 100 studies concluded that the displacement of whole-food diets by UPFs is a key driver of multiple chronic diseases, supported by multiple mechanisms beyond nutrient content.