Understanding the Growing Controversy with Ultraprocessed Foods

December 16, 2025 •

4 min read

According to the American Medical Association, ultraprocessed foods account for 57% of caloric intake in adults and a staggering 67% in children, fueling a national and global health crisis. This widespread consumption is at the heart of a fierce debate among scientists, nutritionists, and policymakers about whether these industrially-created products are inherently harmful or simply correlated with poor health outcomes.

Quick Summary

The debate over ultraprocessed foods involves conflicting evidence and concerns regarding ingredients, processing, and consumer health. It includes criticism of the broad NOVA classification and discussions about health risks like obesity, chronic disease, and mental health issues. Economic factors influencing consumer choices are also a key part of the conversation.

Key Points

Health Concerns: Numerous studies link high UPF consumption to over 30 adverse health outcomes, including heart disease, Type 2 diabetes, obesity, and mental health disorders.
Engineered for Overconsumption: UPFs are intentionally designed to be hyper-palatable with specific combinations of fat, sugar, and salt that trigger the brain's reward system, potentially leading to increased calorie intake and weight gain.
Additive and Ingredient Issues: The industrial ingredients and additives, such as emulsifiers, can negatively impact gut health and contribute to inflammation, though more human research is needed.
Classification Debate: Critics argue that the NOVA classification system is overly broad and lacks nuance, classifying some nutritionally beneficial foods as ultraprocessed alongside less healthy options.
Socioeconomic Factors: UPFs are often more affordable and convenient than whole foods, making them a common choice for lower-income populations and those with limited time or resources.
The Need for Policy: Experts call for better regulation and targeted public health strategies, like the recent school food legislation in California, to address the systemic issues surrounding UPF production and consumption.

What Are Ultraprocessed Foods?

To understand the controversy, one must first grasp the definition of ultraprocessed foods (UPFs). The most widely recognized system is the NOVA classification, developed by Brazilian researchers. This system sorts foods into four groups based on their level of processing. UPFs, in group four, are defined as industrial formulations made mostly or entirely from substances derived from food, often containing a long list of additives, colorings, and flavor enhancers not typically used in home cooking. These items are designed to be highly profitable, convenient, and "hyper-palatable," meaning they are engineered to be irresistibly tasty.

Examples of UPFs include:

Packaged snacks, cookies, and chips
Carbonated and sugary drinks
Pre-prepared or frozen meals (e.g., frozen pizza, TV dinners)
Processed meats like sausages, hot dogs, and some deli meats
Mass-produced bread, cereals, and baked goods
Candy, ice cream, and sweetened yogurts

The Scientific Case Against UPFs

The primary source of the controversy stems from a large body of observational studies linking high UPF consumption to numerous negative health outcomes. A 2024 umbrella review of meta-analyses published in The BMJ found compelling evidence associating higher UPF intake with 32 health consequences, including cardiovascular disease-related death, Type 2 diabetes, and mental health disorders like anxiety and depression.

Hyper-palatability and Overconsumption

One proposed mechanism for UPF's harmful effects is their hyper-palatability. These foods are designed with specific combinations of fat, sugar, and sodium that can override the brain's satiety signals, encouraging people to eat more than they need. This was dramatically demonstrated in a small but influential 2019 randomized controlled trial conducted by Kevin Hall at the National Institutes of Health. Participants on an ultraprocessed diet consumed about 500 more calories per day and gained weight, while the minimally processed group lost weight, even though both diets were matched for calories and nutrients. The UPF group also ate faster, a factor linked to reduced feelings of fullness.

Additives and the Gut Microbiome

Another area of concern is the impact of various additives on gut health. Emulsifiers, artificial sweeteners, and other chemicals commonly found in UPFs have been shown in preclinical studies to affect the gut microbiome and intestinal permeability. These changes can lead to inflammation, which is implicated in a range of chronic diseases. Lecithin, carrageenan, and xanthan gum are among the common emulsifiers now under scientific scrutiny.

Critiques of the Anti-UPF Stance

Not all experts agree on the significance or interpretation of the evidence. Critics argue that the science is not yet robust enough to make definitive causal claims and that several factors complicate the narrative.

Flaws in the NOVA System

A major point of contention is the NOVA classification itself. Critics argue it's too broad, grouping nutritionally disparate foods together. For instance, mass-produced whole-wheat bread is categorized alongside sugary cereals, despite potentially offering some nutritional benefits. This lack of nuance makes it difficult to isolate the effects of processing versus a poor nutrient profile. Some fortified cereals or plant-based milks, while ultraprocessed, might offer valuable nutrients for some people.

Confounding Factors and Lifestyle

Many observational studies link UPFs to poor health, but critics question if the processing itself is the problem or if it's simply a marker for an overall unhealthy lifestyle. People who consume more UPFs may also have lower income, be less physically active, and have less time for home cooking, all of which are independent risk factors for poor health. It is challenging for studies to completely separate these interwoven factors.

The Role of Convenience and Affordability

For many, UPFs are a lifeline. They are affordable, readily available, and require minimal preparation. For those with limited time or income, whole, minimally processed foods can be more expensive and harder to access. Policy recommendations to simply avoid UPFs often fail to consider these critical socioeconomic factors, potentially exacerbating food insecurity for vulnerable populations.

Ultraprocessed vs. Minimally Processed Foods

To highlight the key differences, consider this comparison based on the NOVA classification:


Feature	Minimally Processed Foods (NOVA Group 1)	Ultraprocessed Foods (NOVA Group 4)
Processing Level	Minimal alteration for safety, preservation, or convenience.	Extensive industrial processing with added substances.
Key Ingredients	Whole foods (fruits, vegetables, fish, eggs, whole grains), sometimes with simple additives like water.	Industrial ingredients, substances extracted from food (protein isolates, fats), and numerous additives.
Nutrient Density	High in vitamins, minerals, and natural fiber.	Often low in nutrients and fiber; high in added sugar, fat, and salt.
Palatability	Depends on natural flavors; not engineered for addictive qualities.	Engineered to be hyper-palatable, stimulating reward centers in the brain.
Shelf Life	Often perishable; refrigeration or freezing is common.	Long shelf life due to processing and preservatives.
Examples	Fresh fruit, frozen vegetables, plain yogurt, dried beans, pasta, rice, fresh meat.	Packaged snacks, sugary cereals, soft drinks, chicken nuggets, ice cream, many ready-to-eat meals.

Conclusion: A Complex Public Health Challenge

The controversy with ultraprocessed foods is not a simple black-and-white issue. On one side, mounting epidemiological evidence links high consumption of these products to a myriad of chronic diseases and overall mortality. The behavioral and physiological impacts of hyper-palatability and industrial additives provide plausible mechanisms for these negative health effects. On the other side, critics point out the limitations of the current classification system and highlight the socioeconomic reasons for UPF reliance. Moving forward requires a balanced approach. It is clear that a diet predominantly composed of UPFs is detrimental to health. However, solutions must go beyond simply demonizing these foods and address systemic issues of affordability, access, and education. Consumers can take pragmatic steps by prioritizing whole foods and reading labels, but significant improvements will require better public health policies and industry accountability, as seen with recent legislation like California's school food bans. For further reading on the debate, the full context of the Nova classification is detailed by researchers at the FAO: Ultra-processed foods, diet quality and human health.

Frequently Asked Questions

The NOVA classification is a system developed by Brazilian researchers that categorizes foods into four groups based on their level of processing: unprocessed/minimally processed, processed culinary ingredients, processed foods, and ultraprocessed foods.

No, not necessarily. The controversy highlights that while many UPFs are low in nutrients and high in additives, the broadness of the NOVA system means some fortified cereals or plant-based items are included and may offer nutritional value. However, the overall dietary pattern associated with high UPF intake is linked to poor health.

Hyper-palatability refers to the scientifically engineered combination of fat, sugar, and sodium in UPFs that makes them highly appealing. This combination can trigger the brain's reward centers, dulling the natural signals that tell you when you are full and leading to excess calorie consumption.

UPFs have a higher environmental impact due to energy-intensive manufacturing, extensive packaging, and long supply chains. Their production often relies on a handful of high-yield crops, which can negatively affect biodiversity and promote monoculture.

A good indicator is the ingredient list. UPFs often contain many unfamiliar or industrial-sounding ingredients, including additives like emulsifiers, stabilizers, artificial flavors, and preservatives that you wouldn't find in a home kitchen.

Most traditional cheeses (like cheddar, brie, or mozzarella) are classified as processed foods (NOVA Group 3), not ultraprocessed. However, certain industrial cheese products, like cheese slices, spreads, or shredded cheese with added emulsifiers and preservatives, fall into the ultraprocessed category.

You can start by making small changes, such as cooking more at home, shopping the perimeter of the grocery store for fresh produce and whole foods, and opting for minimally processed alternatives like plain yogurt instead of flavored ones. Reading labels and focusing on whole, nutrient-dense foods is key.