What Are Ultra-Processed Foods?

Not all processed food is created equal. The term ultra-processed comes from the NOVA classification system, developed by researchers at the University of São Paulo, which groups foods by the extent and purpose of their processing — not just their nutrient content.

Under NOVA, foods fall into four groups:

  1. Unprocessed or minimally processed: Fresh fruit, vegetables, plain meat, eggs, milk.
  2. Processed culinary ingredients: Flour, oil, salt, sugar used in home cooking.
  3. Processed foods: Canned vegetables, cheese, cured meats, freshly baked bread.
  4. Ultra-processed foods (UPFs): Industrial formulations containing ingredients rarely used in home kitchens — emulsifiers, flavor enhancers, artificial colors, hydrogenated fats, and modified starches.

Common examples of UPFs include packaged snack foods, carbonated soft drinks, flavored yogurts, instant noodles, breakfast cereals with added sugar, and many fast food products.

The Defining Characteristics of UPFs

What makes a food ultra-processed isn't simply that it contains additives — it's the combination of industrial processing techniques and functional ingredients designed primarily to extend shelf life, enhance palatability, and encourage overconsumption. UPFs are typically:

  • Energy-dense but nutrient-poor
  • High in added sugar, salt, and saturated or trans fats
  • Low in fiber, vitamins, and minerals relative to calorie content
  • Engineered for hyper-palatability (the "can't eat just one" effect)
  • Marketed aggressively, particularly to children

What Does the Research Show?

Over the past decade, a growing body of observational research has associated higher UPF consumption with a range of adverse health outcomes. Key findings from large-scale studies include associations with:

  • Obesity and weight gain – UPFs may undermine satiety signals, leading to greater calorie intake.
  • Type 2 diabetes – High glycemic load and refined carbohydrates contribute to insulin resistance over time.
  • Cardiovascular disease – Elevated sodium, saturated fat, and trans fat content are linked to hypertension and arterial inflammation.
  • Colorectal cancer – Several large cohort studies have found associations between high UPF intake and increased colorectal cancer risk.
  • Depression and mental health – Emerging research suggests links between UPF consumption and depressive symptoms, though mechanisms are still being studied.

An Important Caveat: Correlation vs. Causation

Most UPF research to date is observational, meaning it identifies associations but cannot definitively prove that UPFs cause these outcomes. People who eat more UPFs may also have other lifestyle factors that contribute to poor health. However, a randomized controlled trial published by the NIH did find that participants assigned to an ultra-processed diet consumed significantly more calories and gained more weight compared to those eating minimally processed diets — even when both diets were matched for nutrients — suggesting something beyond simple nutrient content is at work.

The Food Additive Question

Regulators generally approve food additives based on safety at specific exposure levels. However, scientists are increasingly examining the effects of chronic, combined exposure to multiple additives — something that was not a focus of earlier safety assessments. Research into specific emulsifiers, artificial sweeteners, and certain preservatives and their effects on the gut microbiome is an active and evolving area.

Practical Guidance for Consumers

You don't need to eliminate all processed food — that would make everyday eating nearly impossible for most people. Instead, consider a graduated approach:

  1. Prioritize whole and minimally processed foods as the foundation of your diet: vegetables, legumes, whole grains, fruit, eggs, plain dairy, and unprocessed meat or fish.
  2. Read ingredient lists rather than just nutrition panels. A long list of unfamiliar additives is a useful signal.
  3. Cook more from scratch when feasible. Home-cooked meals using simple ingredients offer far more control over what you're consuming.
  4. Be label-savvy about marketing language — "natural," "wholesome," and similar terms on packaging are not regulated claims and don't indicate a food is minimally processed.
  5. Treat UPFs as occasional foods rather than dietary staples.

The Bottom Line

The science on ultra-processed foods is still developing, but the weight of current evidence suggests that reducing their share of your diet — and replacing them with whole or minimally processed alternatives — is a reasonable, well-supported public health goal. Making that shift doesn't require perfection; it requires awareness and gradual, sustainable change.