Are ultra-processed foods a public health hazard?

Are ultra-processed foods a public health hazard? I'll gather the latest evidence on their health risks.

Yes, according to current evidence, high consumption of ultra-processed foods (UPFs) is considered a public health hazard by many researchers and public health bodies, though the picture is nuanced.

What are ultra-processed foods?

There is no universally accepted regulatory definition, but most research uses the NOVA Food Classification System. NOVA was a milestone published in 2009 that categorises foods by type, intensity and purpose of processing.

Ultra-Processed Foods (UPF; NOVA "Group 4") refers to "industrial formulations made entirely or mostly from substances extracted from foods (oils, fats, sugar, starch, and proteins), derived from food constituents (hydrogenated fats and modified starch), or synthesized in laboratories from food substrates"

Other definitions describe them as "formulations of ingredients, mostly of exclusive industrial use, that result from a series of industrial processes"

The ultra-processed group includes all foods and drinks made using intense physical or chemical processes or containing cosmetic food additives and other industrial ingredients (eg, artificial flavours, hydrogenated oils, glucose/fructose corn syrup)

These foods are generally convenient, affordable, highly palatable, and often intensively advertised. Examples under NOVA include candies, packaged snacks, sugary drinks, and ready-to-eat meals. They tend to be high in sugar, salt, and unhealthy fats but low in essential nutrients such as fiber and vitamins

Evidence linking UPFs to adverse health outcomes

The strongest synthesis to date is a 2024 umbrella review of epidemiological meta-analyses published in The BMJ:

Using pre-specified evidence classification:

A more recent large synthesis published September 2024 in Family Medicine and Community Health pooling 51 prospective cohort studies involving nearly 9 million participants found similar results:

People with the highest UPF consumption had a:

Dose-response analysis found for every extra 100 grams (about 3.5 ounces) of UPFs consumed daily, risks increased by:

There is also experimental evidence: Researchers have also conducted clinical trials showing that people who consume a diet high in ultra-processed foods tend to overeat and gain unwanted weight

Researchers have found links between the consumption of highly processed foods (commonly called ultra-processed foods, or UPFs) and a range of negative health outcomes, including cardiovascular disease, obesity and certain cancers

Plausible mechanisms

Researchers propose several plausible mechanisms:

"Plausible mechanisms for harm include nutrient imbalances, overeating, reduced consumption of health-protective [plant compounds], toxic contaminants from processing or packaging, harmful additives and mixtures of additives, and subsequent inflammation," the researchers wrote, adding that a diet high in UPFs may also disrupt blood sugar and cholesterol levels, gut bacteria, and kidney or liver function

Other highlighted mechanisms:

Why public health experts call it a hazard

The umbrella review concluded:

Greater exposure to ultra-processed food was associated with a higher risk of adverse health outcomes, especially cardiometabolic, common mental disorder, and mortality outcomes

These findings provide a rationale to develop and evaluate the effectiveness of using population based and public health measures to target and reduce dietary exposure to ultra-processed foods for improved human health

A BMJ analysis in 2023 argued: Incomplete understanding of the multiple mechanisms underlying the link between ultra-processed foods and cardiometabolic health should not be an excuse for inaction

Policy movement reflects this concern:

Researchers have also noted that because many chronic diseases often occur together, reducing UPF intake could be an important step in preventing multiple health problems at once

Important nuances and limitations

"While many ultra-processed foods tend to be of poor nutritional quality and should generally be limited or avoided, processing itself is not inherently harmful,"

A much-discussed study found the increased disease risk was mainly driven by sugary soft drinks and processed meats (e.g., sausages). In contrast, the study found no increased risk for plant-based highly processed products

Similarly, foods such as some whole grain breads, breakfast cereals and dairy products were associated with lower colorectal cancer risk, while processed meats were associated with higher risk

A dietitian noted: "[A] sugary soda and a fiber-rich packaged whole grain bread may both meet criteria for ultra-processing, but they're nutritionally very different,"

Bottom line

At the population level, evidence consistently links higher UPF intake — especially sugary drinks, processed meats, packaged snacks, and ready-to-eat meals high in added sugars, salt and unhealthy fats — to higher risks of obesity, type 2 diabetes, cardiovascular disease, depression, digestive diseases, cancer and premature death. This supports calls for public health measures to reduce exposure.

This does not mean every food classified as ultra-processed is equally hazardous. Fortified whole-grain cereals, canned beans, or plain yogurts that are technically ultra-processed under NOVA may still contribute nutrients and are not consistently linked to harm. Public health guidance focuses on reducing overall dietary pattern reliance on hyper-palatable, nutrient-poor UPFs and prioritizing whole or minimally processed foods most of the time, cooking at home, limiting sugary drinks and processed meats, and checking labels for added sugars, sodium and saturated fat.