Despite the many benefits of food processing (nutrient fortification, extended shelf-life, convenience, safety, etc.), many consumers have a negative perception of processed foods.1,2 Interest in the health impact of food processing has seen a dramatic resurgence of late. The U.S. Department of Agriculture (USDA) defines processed foods as those which have undergone any changes to their natural state, and by this definition, most foods sold in grocery stores are processed. However, the issue at hand is not so much processing in general, but ultra-processing. In fact, in the past 2 years alone research on ultra-processed foods (UPFs) has increased 250%.
UPFs are so frequently discussed by social and traditional media that one might think this term has been part of nutrition lexicon since the USDA came up with the 4 food groups (“Basic Four”) 70 years ago.3 However, this term is relatively new. It was coined in 2009 by Brazilian researchers who developed the NOVA (not an acronym) food classification system.4 Having an understanding of UPFs is becoming a necessity for many health professionals since UPF intake is associated with a variety of adverse health outcomes (obesity, diabetes, cardiovascular disease, etc.).5 According to recent National Health and Nutrition Examination Survey data, U.S. consumers receive 57% of calories from UPFs.6
As more fully outlined in the secondary article of this newsletter, there are many food classification systems (e.g., Health Star Rating system, Nutri-Score) designed to provide consumers with numerical values describing the healthfulness of foods. For the most part, these systems are based on nutrient and fiber content, giving higher scores to foods that have more of the desirable – or shortfall – nutrients and lower scores to foods that contain too much of less desirable nutrients, like sodium and saturated fat. In contrast, NOVA classifies foods into 4 different groups based entirely on the extent to which they have been processed.
Group 1 foods are unprocessed or minimally processed (e.g., milk, meat, legumes, fruits, vegetables), that is, foods that tend to be in their natural state. In contrast, group 4 foods (UPFs) are often made from substances extracted from foods, such as isolated proteins, and contain one or more additives. Note that critics of NOVA argue that this category is not well defined. In some respects, NOVA is an extension of the clean label movement7,8 and of the belief that the length of the ingredient list is reflective of the healthfulness of a food.
|
Group |
Description |
Examples |
|
Group 1 |
Unprocessed and minimally processed foods |
Fresh, squeezed, chilled, frozen, or dried fruit and leafy and root vegetables; grains such as brown, parboiled or white rice, corn cob or kernel, wheat berry or grain; legumes such as beans, lentils, and chickpeas; starchy roots and tubers such as potatoes, sweet potatoes and cassava; fungi such as fresh or dried mushrooms; meat, poultry, fish and seafood, whole or in the form of steaks, fillets and other cuts; fresh, powdered, chilled or frozen eggs; fresh, powdered or pasteurized milk; fresh or pasteurized fruit or vegetable juices (with no added sugar, sweeteners or flavors); grits, flakes or flour made from corn, wheat, oats, or cassava; tree and ground nuts and other oily seeds (with no added salt or sugar); herbs and spices used in culinary preparations, such as thyme, oregano, mint, pepper, cloves and cinnamon, whole or powdered, fresh or dried; fresh or pasteurized plain yoghurt; tea, coffee, and drinking water. |
|
Group 2 |
Processed culinary ingredients |
Vegetable oils crushed from seeds, nuts or fruit (notably olives); butter and lard obtained from milk and pork; sugar and molasses obtained from cane or beet; honey extracted from combs and syrup from maple trees; starches extracted from corn and other plants; vegetable oils with added anti-oxidants; salt mined or from seawater, and table salt with added drying agents. |
|
Group 3 |
Processed foods |
Canned or bottled vegetables and legumes in brine; salted or sugared nuts and seeds; salted, dried, cured, or smoked meats and fish; canned fish (with or without added preservatives); fruit in syrup (with or without added anti-oxidants); freshly made unpackaged breads and cheeses. |
|
Group 4 |
Ultra-processed foods |
Many ready-to-consume products such as carbonated soft drinks; sweet or savory packaged snacks; chocolate, candies (confectionery); ice-cream; mass-produced packaged breads and buns; margarines and other spreads; cookies (biscuits), pastries, cakes, and cake mixes; breakfast ‘cereals’, ‘cereal’ and ‘energy’ bars; ‘energy’ drinks; milk drinks, ‘fruit’ yoghurts and ‘fruit’ drinks; ‘cocoa’ drinks; ‘instant’ sauces. Many pre-prepared ready-to-heat products including pies and pasta and pizza dishes; poultry and fish ‘nuggets’ and ‘sticks’, sausages, burgers, hot dogs, and other reconstituted meat products; and powdered and packaged ‘instant’ soups, noodles and desserts. Infant formulas, follow-on milks, other baby products; ‘health’ and ‘slimming’ products such as meal replacement shakes and powders. |
Monteiro CA, Cannon G, Lawrence M, Costa Louzada ML, Pereira Machado P. Ultra-processed foods, diet quality, and health using the NOVA classification system. Rome; 2019.
The emergence and embracement of NOVA by organizations such as the Food and Agriculture Organization (FAO) of the United Nations9 is relevant to the soy industry because plant-based milks (including soymilk made from whole soybeans) and plant-based burgers, links, nuggets, etc. (including those based on soy protein) are almost without exception classified as UPFs.10 In contrast, the animal-based counterparts to these foods, cow’s milk and meat (unprocessed), are classified as group 1 foods.11 The stigma of UPFs could discourage people from consuming soy-based burgers and soymilk, even though the major criticisms of UPFs do not apply to these soy products.
As noted, one of those major criticisms is that UPF intake is linked with adverse health outcomes; however, it is important to consider why this link exists. It is reasonable to assume these relationships exist because UPFs are associated with poor diet quality.12 However, several analyses have concluded that these associations exist independent of diet quality, even though it probably is not possible to control completely for diet quality.13,14 Nevertheless, more attention is being directed toward the health impact of additives, particularly those designed to enhance a final product’s sensory properties which make the food more attractive to see, taste, smell, and/or touch, which increases the potential for overconsumption.15 Emphasis is also being placed on the effects of degrading the food matrix that can occur with ultra-processing which can, for example, raise the glycemic index of food without altering its nutrient content.16
At this point, it is fair to conclude that a full understanding of the health effects of UPFs has yet to be achieved, but research is contributing to the body of literature. Recent clinical research by Hall and colleagues from the National Institutes of Health markedly raised the profile of NOVA and UPFs.17 In brief, this cross-over study found that participants gained weight while consuming ad libitum, a diet comprised of UPFs for 2 weeks, whereas weight was lost when they consumed a diet comprised of unprocessed or minimally processed foods. The weight gain resulted from participants consuming ~500 kcal/d more while on the UPF diet. Although there could be several reasons why this occurred, evidence suggests it was because of the greater energy intake rate of UPFs. That is, the UPFs were consumed more quickly (eating rate) and were more energy dense (kcal/g), which are major criticisms of UPFs.
As noted previously, soymilks and soy-based burgers are classified as UPFs because of certain ingredients they contain. Many soymilks contain additives such as gellan gum, a gelling agent, and soy-based burgers are based on concentrated sources of soy protein. However, evidence indicates that common attributes associated with UPFs — such as high energy density, increased eating rate, hyperpalatability/low satiety, and high glycemic index — do not apply to soyfoods more so than to meat and cow’s milk, which are classified as group 1 foods.
Although NOVA has been embraced by the FAO and incorporated into the dietary guidelines of several countries, many reviews of NOVA have been published questioning its approach, and there has been considerable pushback against NOVA.13,18,19 It is beyond the scope of this article to discuss those criticisms; however, the contrast between NOVA and other food classification systems highlights the lack of focus on nutrient content in the former. For example, within the same NOVA-classified group, food ratings vary widely according to the Food Compass and other nutrient profiling systems (see next article).20
In the opinion of this author, processing is but one factor that potentially influences the nutritional composition and potential physiological effects of foods. Classifying foods entirely based on processing fails to consider the complexity of foods and may end up discouraging the consumption of foods that can help meet nutrient needs and positively contribute to overall health.
REFERENCES
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3. Page L, Phipard EF. Essentials of an adequate diet: U.S. Dept. of Agriculture, Agricultural Research Service; 1956.
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20. Mozaffarian D, El-Abbadi NH, O’Hearn M, J E-M, Masters WA, Jacques P, Shi P, J.B B, Micha R. Food Compass is a nutrient profiling system using expanded characteristics for assessing healthfulness of foods. Nature Food 2021.