In the late 2000s, researchers at the Center for Epidemiological Studies in Health and Nutrition, in Brazil, were pioneers in pointing out changes in industrial food processing as the main driver of the obesity pandemic, which started in the United States in the 1980s and, in the 21st century, has reached most countries in the world.

These observations have led to the categorizing of food based on how and why food products undergo industrial processing before being purchased or consumed. This classification, known as Nova, assumes that the extent and purpose of processing to which food is subjected determines its nutrient content and other attributes, potentially influencing the risk of obesity and other diet-related diseases.

Before Nova, foods were classified based on whether they were significant sources of specific nutrients, regardless of their processing. Thus, cereal grains, flours from these grains, pasta, bread, biscuits, breakfast cereals and cereal bars were all classified as carbohydrate sources. Fresh meat, salted meat and sausages were classified as protein sources — as were milk, cheese and dairy drinks or desserts. Fruits, fruit drinks, vegetables, and canned vegetables were classified as sources of vitamins and minerals.

Since its launch, the Nova classification has conquered the world, supporting hundreds of studies that have confirmed that the increase in consumption of ultra-processed foods, one of the four classified groups, is related to the pandemic of obesity and other chronic diseases affecting the planet.

Find out more about the classification below.

HISTORY

Until the late 2000s, little was said about the effects of food processing on human health.

To provide some context, in 2003, the World Health Organization released a technical report on diet, nutrition, and the prevention of chronic diseases. In the paper, a worldwide trend of increasing obesity was identified and related to increasing urbanization and its impact on diets, which have become richer in fat and calories (and poorer in fibre and micronutrients).

Many causes were listed in the report, including high consumption of sugary drinks, eating foods with high energy density and low vitamin and mineral content, and heavy marketing by the fast food industry. However, the connection of these causes with food processing did not appear clear. 

The understanding of the issue began to change in 2009, following the release of a commentary by the Center for Epidemiological Studies in Health and Nutrition (Nupens), from Brazil: The problem is not the food nor the nutrients but the processing. 

Published by the journal Public Health Nutrition, one of the British Nutrition Society’s publications published by Cambridge University Press, the commentary, written by the scientific coordinator of Nupens, Carlos Augusto Monteiro, emphasized that it is insufficient to only consider nutrient content when trying to understand the relationship between food and health. It also described various attributes of foods modified by processing and proposed classifying food products according to the extent and purpose of their processing. Thus, the concept of ultra-processed food and the embryo of the Nova classification was born. 

In 2014, Nova provided a scientific foundation and consequently served as the basis for the recommendations of the Dietary Guidelines for the Brazilian Population. Since then, the classification has directly impacted public policies on nutrition and health in Brazil. The influence has also reached abroad, as the Brazilian Guide has influenced similar publications in several other countries, including Uruguay, Canada, Peru, Ecuador, Israel and, more recently, Mexico. 

The inclusion and popularization of the term “ultra-processed” in science has also made it possible to monitor the consumption of products in this category in populations, with a new orientation for analyzing food consumption surveys. 

This information generates important contributions to public health.

THE ALIMENTARY GROUPS

The Nova classification organizes foods into four categories. Learn about each of them below.

GRUP 1

Unprocessed or minimally processed food

Unprocessed food is that to which we have direct access as it comes from nature. The term includes edible parts of plants (such as seeds, fruits, leaves, and roots) or animals (muscles, eggs, milk). It also includes mushrooms and seaweed. 

Minimally processed foods are basically fresh foods that need some processing before reaching the final consumer, but with no added ingredients or transformations that make them uncharacteristic. Beans are just dried and packed; wheat grains are transformed into flour, couscous, and pasta; corn grains into flour and polenta; coffee beans are roasted and ground; milk is pasteurized; meat is chilled or frozen — all these are processes that increase the shelf life and facilitate the consumption of food without substantially altering its main properties. In this category, the use of preservatives and fortifiers is accepted.

GRUP 2

Processed culinary ingredients

When we base our diet on fresh or minimally processed options, we often need to cook and season food. This is the step where the foods in the second group of the Nova classification come in. 

Processed culinary ingredients are substances extracted from foods of the first group by physical procedures such as pressing, centrifugation, and concentration. This is the case, for example, with olive oil obtained from olives, butter obtained from milk, and sugar obtained from cane or beet. They can also be extracted directly from nature, such as sea and rock salt. 

These ingredients are essential for converting foods from the first group into delicious recipes and meals. When used in small quantities, they are perfectly compatible with a nutritionally balanced and healthy diet.

GRUP 3

Processed food

The category of processed foods is composed of items from the first group (unprocessed and minimally processed) modified by relatively simple industrial processes that could be carried out in a domestic environment. They rely on adding one or more substances of the second group, such as salt, sugar, or fat. 

The group includes, for example, canned vegetables or fish, fruit in syrup, and artisan-type cheeses and bread. Processed foods increase the shelf life of their original ingredients, as well as helping to diversify the diet. If consumed in small quantities and as part of meals based on foods from the first group, they are also compatible with a nutritionally balanced and healthy diet.

GRUP 4

Ultra-processed food and drinks

Ultra-processed foods – which can be foods and drinks – are not really foods but formulations of substances obtained by fractionating foods from the first group. These substances include sugar, oils, and fats for domestic use, protein isolates or concentrates, interesterified oils, hydrogenated fat, modified starches, and various substances for exclusive industrial use. 

Added colors, flavors, emulsifiers, thickeners, and other additives that give the formulations sensory properties similar to those found in foods from the first group are added into ultra-processed foods. They also serve to disguise undesired characteristics of the final product. Despite the claims commonly seen on the packaging of ultra-processed products, unprocessed foods are just a small percentage of their composition or are simply absent, as in the case of “strawberry flavored” or “grape flavored” products. 

The processes and ingredients used to manufacture ultra-processed foods are developed to create highly profitable products (low-cost ingredients, long shelf life, branded products) that can replace all other Nova food groups. Their convenience (imperishable, ready-to-eat), hyper-palatability (extremely tasty and flavorful), promotion by transnational corporations, and aggressive marketing give ultra-processed foods huge market advantages over all other food groups. 

Ultra-processed foods include soft drinks, dairy drinks, fruit nectar, powdered mixes for making fruit-flavored drinks, ‘packaged snacks’, sweets and chocolates, cereal bars, ice cream, packaged bread and other bakery products, margarine and other butter substitutes, biscuits, cakes and cake mixes, morning cereals, pies, pasta dishes and pre-prepared pizzas, chicken and fish nuggets, sausages, hamburgers and other reconstituted meat products, instant noodles, powdered mixtures for preparing soups or desserts and many other products.

EVIDENCE

The idea that ultra-processed foods are linked to an increased risk of obesity and other diet-related chronic diseases may seem obvious, but its onset has been received skeptically. However, today, several studies demonstrate these products’ harmful effects.

One of the most important studies on the harmful effect of ultra-processed foods on health was conducted at the world’s largest health research laboratory, the United States’ National Institutes of Health. The scientist Kevin Hall from this institute isolated 20 healthy adults for a month. Using the Nova classification, half of the participants in the study were offered meals free of ultra-processed foods for a fortnight. For the other half, the meals contained basically only ultra-processed foods (about 80% of the calories). Over the next two weeks, the diet of the two groups was reversed. 

Both diets offered the same amount of calories and macronutrients (carbohydrates, proteins, and fats). Each person could eat as much as they wanted. The result showed that during the period of the ultra-processed diet, the participants gained an average of one kilo in a fortnight. On the other hand, during the period of the non-ultra-processed diet, there was a weight loss, also of an average of one kilo over two weeks. The full results of Kevin Hall’s clinical trial were published in 2019 in the prestigious journal Cell Metabolism. 

In France, a significant study by the Group for Research in Nutritional Epidemiology at the University of Paris monitored the diet of over 100,000 adults for several years to relate the dietary pattern of each person to the risk of becoming ill. The results, published in highly regarded medical journals such as British Medical Journal, JAMA, and PloS Med, demonstrated the clear association of ultra-processed food consumption with the incidence of obesity, diabetes, cardiovascular disease, depression, and breast cancer, and also with the risk of dying early from any cause. 

After extensive cohort studies conducted in Spain, the United States, the United Kingdom and Brazil, it has been confirmed that ultra-processed food consumption is associated with the incidence of obesity, diabetes, cardiovascular disease, depression, and lower life expectancy. 

The Nova classification is already an international reference, and inspires projects such as Perfact, which helps consumers filter foods and identify when they are ultra-processed, opting for healthy choices.