What Makes a Food 'Ultra-Processed'? Inside the Science and the Push to Label Them

The grocery store aisle is a notoriously confusing place, but a new legislative push in California is attempting to cut through the noise. Assemblymember Jesse Gabriel recently introduced a bill to create a "California Certified" seal for foods that are not ultra-processed, aiming to give shoppers a quick visual cue similar to the organic label.[1][2]

This proposed certification follows a landmark 2025 law that phased out the most concerning ultra-processed foods from California public schools, setting the first legal definition of the term in the United States.[1]

The legislative momentum reflects a growing scientific consensus that heavily engineered foods are uniquely harmful to human health. However, it also highlights a major consumer hurdle: while nearly 60 percent of adults have heard the term "ultra-processed," only about a third feel confident defining what it actually means.

To understand the debate, nutritionists rely on the NOVA classification system, a framework developed by researchers at the University of São Paulo. Unlike traditional dietary guidelines, NOVA categorizes food not by its nutrients—like fat, protein, or carbohydrates—but by the extent and purpose of its industrial processing.

The system divides the food supply into four tiers. Group 1 consists of unprocessed or minimally processed foods, such as fresh fruit, vegetables, eggs, and milk. Group 2 includes processed culinary ingredients like olive oil, butter, and salt, which are extracted from nature and used to cook Group 1 foods.

Group 3 covers processed foods, which are typically made by combining the first two groups. This category includes items like freshly baked bread, canned beans, salted nuts, and cheese. These foods are modified to extend their shelf life or enhance their taste, but they remain recognizable versions of their original ingredients.

Group 4 is where the health concerns are concentrated: ultra-processed foods (UPFs). These are industrial formulations made mostly or entirely from substances extracted from foods, derived from food constituents, or synthesized in laboratories.

The hallmark of an ultra-processed food is the presence of ingredients you would never find in a standard home kitchen. If a nutrition label lists high-fructose corn syrup, hydrogenated oils, protein isolates, or cosmetic additives like emulsifiers, artificial flavors, and thickeners, the product is ultra-processed.

For decades, the health risks of these foods were attributed simply to their poor nutritional profiles, as they tend to be high in added sugar, sodium, and saturated fat. But recent research suggests that the industrial processing itself is an independent risk factor for chronic disease.[4]

A major observational study from Tufts University analyzed two decades of dietary data and found that people who ate more UPFs had worse health outcomes, even when the overall nutritional quality of their diet was accounted for. Researchers suspect that the industrial destruction of the food's cellular structure, combined with the loss of beneficial chemical compounds and the addition of packaging chemicals, creates distinct metabolic risks.[4]

The sheer scale of the health impact is staggering. An umbrella review published in The BMJ analyzed data from nearly 10 million participants, finding consistent evidence linking high UPF consumption to 32 adverse health outcomes. The data showed a 50 percent increased risk of cardiovascular-related death and a 12 percent greater risk of type 2 diabetes among those with the highest exposure.[3]

The European Society of Cardiology recently echoed these findings, noting that UPFs promote obesity, hypertension, and the build-up of unhealthy fats in the blood. Experts suggest that the altered food structure and cosmetic additives trigger systemic inflammation and disrupt the gut microbiome, overriding the body's natural satiety signals.

The effects of these industrial formulations extend well beyond the heart and waistline, increasingly implicating brain health. A June 2026 study from Monash University found that even modest increases in UPF consumption were associated with measurable declines in attention and mental processing speed.

Researchers noted that a 10 percent increase in UPFs—roughly equivalent to adding a standard packet of chips to a daily diet—led to a distinct drop in a person's ability to focus. The findings raise serious concerns about the hidden cognitive costs of heavily processed foods, linking them to known dementia risk factors even among people who otherwise follow healthy diets.

Despite the mounting evidence, regulating or avoiding UPFs remains complicated because the category is incredibly broad. While it includes obvious culprits like sodas, candy, mass-produced pastries, and ready-to-heat meals, it also captures foods widely considered to be healthy.

A loaf of store-bought whole-grain bread, fortified plant-based milks, and low-fat yogurts often fall into the ultra-processed category because they contain industrial stabilizers, emulsifiers, or added vitamins. This nuance makes blanket bans difficult and highlights the need for more granular research into which specific additives drive the most harm.

This complexity is exactly why California's proposed "California Certified" non-UPF seal is being closely watched by the food industry and public health advocates alike. The voluntary seal aims to give busy shoppers a quick, trustworthy visual cue without requiring them to decode complex ingredient lists in the middle of the grocery aisle.[1][2]

If successful, the California standard could force a nationwide shift in how food is manufactured. Because food companies prefer to maintain a single national supply chain, state-level regulations in California—such as the recent bans on specific food dyes and chemicals—often become the de facto standard for the entire country.[1]

Until clear labeling becomes widespread, dietitians recommend a simple rule of thumb for navigating the supermarket: focus on the perimeter where fresh foods live, and when buying packaged goods, choose items with short ingredient lists that read like a recipe rather than a chemistry experiment.