What is meant by processed foods?

As part of a healthy lifestyle meant to prevent disease, you often read advice to cut back on processed, especially highly processed, foods.

But when is a food considered processed? After all, hardly anyone pulls a carrot out of the ground and eats it straight away. In most cases the carrot gets at least a short bath or a quick rinse to remove the dirt before it ends up on our plate. Is cleaning already a form of processing, or where does a food start to be classified as processed?

A relatively easy-to-understand guide is the NOVA classification. It sorts foods into 4 groups based on how much they have been processed:

Group 1

includes foods that are natural, unprocessed, or only minimally processed. That means after harvest or slaughter they were only cleaned, chilled, frozen, heated, or fermented. Processing in this group is limited to making the product edible or preserving it while keeping it essentially in its natural state. Our washed carrot would fall into this group.

Additives from group 2 are usually not used to extend shelf life. There are rare exceptions, however, such as pasteurized milk, or added stabilizers or antioxidants in vacuum-packed vegetables.

Besides fresh fruit and vegetables, group 1 also includes seeds and roots, as well as milk, eggs (even if heated), yogurt without added sugar or other ingredients, and meat.

Group 2

covers processed products that are mainly used in food preparation. They are made directly from the products listed in group 1 by pressing, refining, milling, or drying. Additives such as anti-caking agents, iodine, or antioxidants may be present here.

What characterizes this group is that the products are usually not eaten on their own, but used as ingredients in cooking. Group 2 includes, for example, natural oils, sugar, salt, honey, butter, lard, and plant starches like corn or potato starch.

Group 3

includes classic, relatively simply processed foods like bread, cheese, or canned goods. Basically these are group 1 foods with group 2 ingredients added. By preserving, fermenting, or by cooking or baking them, their shelf life is extended a main reason for processing products in this group. Another reason is to change or improve texture, appearance, smell, or taste.

A simple example is bread: flour is mixed with water, salt, and leavening agents like yeast or sourdough to make a dough that needs to "rise," i.e. ferment somewhat. Baking then gives it a firmer texture and longer shelf life. The finished product has therefore been changed in appearance, smell, taste, and texture.

Other examples in this group are canned fruit, vegetables, and fish, salted or sugared nuts, cured and smoked meats, and cheese. Alcoholic drinks like wine and beer can also be placed here.

Group 4

includes the so-called highly or ultra-processed foods, which usually contain five or more often many more ingredients. The abbreviation UPF is also common; it stands for "ultraprocessed food".

These products often contain only extracts of group-1 foods, and sometimes hardly any whole foods from that group at all. Instead, they typically include group 2 ingredients that have been heavily processed, such as hydrogenated fats, cheap sugars or sugar substitutes, flavor enhancers, and so on.

They also use substances not normally used in home cooking. These are used to mimic sensory qualities or to mask unwanted ones.

There is an almost endless list of additives that can be used, like flavors, colorings, fillers, emulsifiers, etc., to make the final product tasty, ready-to-eat, shelf-stable, colorful, attractive, and more. The base ingredients are often inexpensive and are transformed flavor-wise by the manufacturing process.

The final product is offered in appealing packaging and often promoted with elaborate marketing strategies.

Group 4 therefore covers a wide range of products, from pre-baked rolls to "diet" products, energy drinks, ready meals, fruit drinks, "health" products, flavored or artificially sweetened yogurts, infant formula, sweets, and frozen swiss rolls. If you consider alcohol a food, you would also find distilled spirits like whisky or vodka here, as well as colorful alcopops.

Why should you know this?

Several studies have shown harmful health effects from consuming ultra-processed foods. People whose diets are mainly ready meals and highly processed products had higher mortality and higher rates of disease. This includes a worse cardiometabolic risk profile meaning a higher risk of developing cardiovascular disease as well as higher overall mortality, an increased cancer risk, more changes in the brain's blood vessels up to and including strokes, and also a higher risk of depression.

A Brazilian study even identified a high intake of highly processed foods as an independent risk factor for early death. The researchers found a linear increase in mortality with increasing consumption of highly processed foods.

Many health-related dietary recommendations therefore advise avoiding highly processed foods, because they often contain a lot of calories, unhealthy fats, lots of salt and/or sugar, and few vitamins and fibers.

On the other hand, the health effects of many possible additives are often unknown or little understood. Time and again the media report potential health risks from these substances. Not infrequently these reports concern additives that were previously considered unproblematic.

Like many other additives, sugar substitutes are often criticized. Erythritol was linked in a 2023 study to increased platelet aggregation, i.e. a tendency toward blood clot formation. Earlier studies also viewed this sugar substitute with concern.

In another 2023 study, researchers found that the artificial sweetener sucralose could affect certain immune cells.

In summary, higher UPF consumption although shown in a limited number of studies was associated with a worse cardiometabolic risk profile and a higher risk of cardiovascular disease, cerebrovascular disease, depression, and overall mortality.

Sources

This article comes from BloodPressureDB – the leading app since 2011 that helps hundreds of thousands monitor their blood pressure every day. Our content is based on carefully researched, evidence-based data and is continuously updated (as of 05/2025).

Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as in outpatient care, and has led BloodPressureDB's specialist editorial team since 2015. Thanks to her extensive additional qualifications as a paramedic, first responder and in various therapy and emergency areas, she provides solid, practical and reliably reviewed information.