Definitions of processed foods: legal and food science

Regulatory and food science definitions are found in Table 1A^(28–36). These definitions show strong congruence but differ in detail. All agree that one or more physical, chemical or microbiological steps change raw commodities into ingredients or foods. All allow formulations with any number or type of ingredients. The United States Department of Agriculture also has a legal definition of MPF⁽³¹⁾.

Table 1. Representative definitions and descriptions of food processing (FP) and processed food (PF)

* Nearly all legal and food science definitions of food processing have similar examples and allow additions to the list as new processed emerge.

† Example of a consumer education group using dietitians and food professionals as spokespeople.

‡ Example of an organic agricultural products marketing and trade resource that is not in favour of biotechnology or pesticides.

§ Example of a US newspaper website.

║ Example of health newsletter associated with the large health system.

¶ Natural is not legally defined in many jurisdictions.

** Example of the newsletter from a vendor of supplements and health foods.

Goals of food processing are also aligned in this group of definitions. These include increasing shelf life, maintaining or enhancing safety and nutrient quality, addressing specific nutritional requirements and adding variety and convenience.

Food scientists

PF exist on a continuum that food scientists base on the complexity of processes, not numbers or kinds of ingredients. Additives, salts and sugars are regarded as part of the recipe, not as processes, and can add flavour but also extend shelf life and preserve nutrients⁽Reference Sandulachi and Tatarov⁶⁰⁾. These components help to fulfill the goal of processing, which is to reduce pre- and post-harvest losses, to minimise resource use, to decrease waste, to maintain safety and quality and to offer convenience⁽Reference van Boekel, Fogliano and Pellegrini^61, Reference Xu, Sun and Zeng⁶²⁾. These may address food supply issues and lower costs⁽Reference Martindale^63, Reference Janssen, Nijenhuis-de Vries and Boer⁶⁴⁾.

Food scientists recognise processing may alter nutrient content and bioavailability, either positively or negatively⁽Reference Wahlqvist and Briggs⁵⁹⁾. Processes and ingredients are adjusted to minimise losses and maintain nutrients. Fortificants may be added to address demonstrated deficiencies^(65, Reference Fulgoni, Keast and Bailey⁶⁶⁾. Additional ingredients can add variety and palatability making nutrients more likely to be ingested⁽Reference Bernstein, Tucker and Ryan⁶⁷⁾. While variety may induce overeating, so can food that is unsatisfying, as people eat more to seek satisfaction. Both aspects need more study⁽Reference Johnson and Wardle⁶⁸⁾.

Nutrition and the food processing continuum

Traditional dietary guidance is based on optimising intakes of food groups and nutrients^{(69, 70)}. Nutrient-poor foods are to be chosen infrequently⁽⁷¹⁾. Vetted diet plans with proven health benefits, such as DASH, use a mix of foods from all levels of processing to help consumers reach nutrition and health targets⁽Reference Challa and Uppaluri^20, Reference Panagiotakos, Notara and Kouvari^72–Reference Duyff⁷⁷⁾. PF are featured in the United States Department of Agriculture MyPlate (ChooseMyPlate.gov) sample menu plans, which are designed to meet recommendations for consumers with limited resources^{(21, 78)}.

International Food Information Council categorisation

Table 2 shows the five categories of the IFIC model. All categories contain foods to choose frequently and infrequently. Addition of sugar, salt or additives or numbers of ingredients had no effect on category placement. Home-prepared foods are categorised with the same criteria as manufactured ones.

Table 2. International food information council (IFIC) processed food categorisation

Adapted from http://www.ific.org.

NOVA

Public Health Professor Carlos Montiero and colleagues initiated the NOVA categorisation of foods found in Table 3⁽Reference Monteiro^1–Reference Montiero, Moubarac and Cannon⁴⁾. Initially, there were three categories, MPF_n, PCI, PF_n⁽Reference Adams and White⁷⁹⁾. Subsequently, PF_n was split into PF_n and UPF_n making four categories. MPF_n are described as undergoing minimal processing such as washing, milling, chilling, freezing, or vacuum-packing (vacuum-packing, especially of cooked, refrigerated vegetables, is viewed by food scientists as one which requires attention to maintain nutrients and safety and has a degree of complexity). PCI include ingredients found in home kitchens, such as starch, sugar and oil. (PCI initially included starch and pasta.) PF_n are defined as recognisable versions of original foods that may have added PCI (e.g. sugar or salt) to extend shelf life or modify palatability. They are generally consumed as part of meals or dishes. UPF_n are described as industrial formulations with five or more ingredients, which are often packaged, branded, convenient and highly palatable and function as snacks or replace homemade dishes. They may include additives, sweeteners and added micronutrients to fortify them.

Table 3. NOVA classification of foods^(2, Reference Moubarac, Batal and Louzada⁶⁾

* PCI_n −2010; MPF_n-2016.

† UPF_n −2010; PF_n-2016⁽Reference Monteiro^1–Reference Montiero, Moubarac and Cannon^4, Reference Moubarac, Batal and Louzada⁶⁾.

The NOVA categorisation was enfranchised by the Pan American Health Organisation⁽²⁾. While Pan American Health Organisation recognises that nearly all foods are processed and notes their benefits and essentiality, they raise concern about and their potential contribution to disease.⁽²⁾ Pan American Health Organisation's document described UPF_n as ‘attractive, hyper-palatable, cheap, ready-to-consume food products that are characteristically energy-dense, fatty, sugary or salty and generally obesogenic.’⁽²⁾.

International Food Information Council

Analyses of US National Health and Nutrition Examination Survey (n   25 351 over 2 years old) showed that MPF_i contributed 17% of energy (E), but over 50% of the vitamin D (mostly due to fortified dairy) and over 30% of the potassium, calcium and vitamin B₁₂⁽Reference Martínez Steele, Baraldi and Louzada^8, Reference Eicher-Miller, Fulgoni and Keast^16–Reference Eicher-Miller, Fulgoni and Keast¹⁸⁾. Foods processed for preservation (mostly canned and frozen) contributed about 5% of E, but over 30% vitamin C and over 5% of potassium, fibre, magnesium, folate, calcium, vitamin B₆ and iron. This category contributed <5% of the salt but 8% of the sugar.

RTE PF_i contributed 35% of E, and higher percentages of iron, folate and vitamin B₆. It also contributed 45% of the added sugars (45%), with major contributions from sugar-sweetened beverages, juice drinks and grain-based snacks and desserts⁽Reference Martínez Steele, Baraldi and Louzada^8, Reference Eicher-Miller, Fulgoni and Keast^16–Reference Eicher-Miller, Fulgoni and Keast¹⁸⁾. Sodium contributions were lower than the percent of E.

Mixtures of ingredients provided 17% of E and slightly more carbohydrate, fibre, thiamin, folate, calcium and iron, but a lower percentage of added sugars than the percent of E.

Prepared foods and meals provided about 4% of E and 5% of protein and sodium and contributed other nutrients equal to or slightly less than the percent of E.

All International Food Information Council processed food categories combined

When IFIC categories containing PF_i (omitting MPF_i) were combined, they contributed 57% of E, but they delivered nutrients of concern (designated by the 2010 US Dietary Guidelines Advisory Committee)⁽Reference Eicher-Miller, Fulgoni and Keast^16–Reference Eicher-Miller, Fulgoni and Keast^{18, 80)}. Specifically, PF_i contributed 45–55% of dietary fibre and nearly all the cereal fibre, 48% of the calcium, 43% of the potassium, 34% of the vitamin D, 64% of the iron, 65% of the folate and 46% of the vitamin B_12. For constituents to limit, total PF_i contributed equivalent or slightly lower percent of E for saturated fat (52%) and sodium (57%). All five IFIC categories provided about 2300 mg sodium with most coming from mixtures of combined ingredients (approximately 700 mg) and RTE foods (approximately 1000 mg). Foods eaten outside the home provided about 1200 mg⁽Reference Eicher-Miller, Fulgoni and Keast^16–Reference Eicher-Miller, Fulgoni and Keast¹⁸⁾.

While MPF_i contributed 5% of the added sugars, the four PF_i combined contributed 75%, and restaurant foods the remainder. The RTE category provided the most added sugars⁽Reference Eicher-Miller, Fulgoni and Keast^16–Reference Eicher-Miller, Fulgoni and Keast¹⁸⁾ but most were from foods dietary guidance recommends limiting such as sugary beverages. However, some added sugars were from foods to encourage such as fibre-rich, enriched and fortified bread and cereals, fruit and dairy.

Diet selection and categorisation

Authors of the IFIC studies⁽Reference Eicher-Miller, Fulgoni and Keast^16–Reference Eicher-Miller, Fulgoni and Keast¹⁸⁾ concluded that diets were more likely ‘to meet… recommendations if nutrient-dense foods, either processed or not, are selected.’ Poti et al.⁽Reference Poti, Mendez and Ng⁸¹⁾ also concluded that while PF had more added sugars, there was a wide variation in nutrient content within categories and that choice within a category mattered. Similar examples are gleaned from healthy dietary patterns such as DASH and the US Healthy-Style Eating Pattern (as symbolised by MyPlate), that show nutritious diets can be constructed with the right mix of PF and MPF⁽Reference Fulgoni, Keast and Bailey^{66, 69,} Reference Panagiotakos, Notara and Kouvari^72–78).

NOVA and nutrients

Several studies correlated the increased availability of UPF_n over the last 30+ years with a decline in overall nutrient quality⁽Reference Montiero, Moubarac and Cannon^4, Reference Popkin and Reardon^10, Reference Moubarac, Batal and Martins^37, Reference Martins, Levy and Claro⁸²⁾. Analyses of food intake data from several countries documented that those who chose the most UPF_n had lower nutrient quality than those who chose the least. In the 2004 Canadian Community Health Survey.2 (n 33 694, >2 years), those in the highest quintile of intake of UPF_n, ate on average 1046 kJ (250 kcals) more, but compared with those in the lowest quintile, ingested lower levels of riboflavin, niacin and vitamins A, B₁₂, C, D and B₆⁽Reference Moubarac, Batal and Louzada⁶⁾. Sodium and energy density were higher for the consumers of UPF_n.

Similar results came from 2008 to 2009 Pesquisa de Orçamentos Familiares (Brazilian Family Budgets Survey of 32 898 individuals over 10 years). UPF_n contributed 21·5% of E⁽Reference Costa Louzada, Martins and Canella⁷⁾. Those in the highest quintile of UPF_n intake consumed more energy but less fibre and potassium. However, the analysis showed that certain PF_n and UPF_n, specifically bread, cheese, processed meats and canned fruit and vegetables, contributed important nutrients. This latter statement agrees with findings from other studies that emphasise choice of foods within a category, not the category itself⁽Reference Eicher-Miller, Fulgoni and Keast^16–Reference Eicher-Miller, Fulgoni and Keast^18, Reference Poti, Mendez and Ng⁸¹⁾.

Added sugars and the NOVA and International Food Information Council classifications

Since NOVA categorises all commercially prepared foods with added sugars as PF_n or UPF_n, it is self-evident that analysis of food intake data would identify them as significant contributors of added sugars. According to the US National Health and Nutrition Examination Survey 2009–2010 (n 9317), UPF_n delivered nearly 60% of E but 90% of the added sugars for children and adults⁽Reference Martínez Steele, Baraldi and Louzada⁸⁾. Canadian data showed UPF_n contributing 49% of E and a significant amount of free sugars⁽Reference Moubarac, Batal and Louzada⁶⁾. Analysis of Chile's 2010 Encuesta Nacional de Consumo Alimentario (n 4920, 2+ years) showed that UPF_n contributed 29% of E and 59% of added sugars⁽Reference Cediel, Reyes and da Costa Louzada⁹⁾. In the 22 116 households participating in the 2010 Spanish Household Budget Surveys (food disappearance, not intake data), UPF_n provided 31·7% of daily E and 80·4% of added sugars⁽Reference Latasa, Louzada and Martinez Steele⁸³⁾. In the Brazilian Pesquisa de Orçamentos Familiares, UPF_n provided 21·5% of E and 29% of added sugars⁽Reference Costa Louzada, Martins and Canella⁷⁾.

Ultra-processed foods-NOVA and obesity

Proponents of NOVA have noted that the rise in obesity over the last 30+ years has paralleled the increased availability of UPF_n⁽Reference Moubarac, Batal and Louzada^6, Reference Costa Louzada, Martins and Canella⁷⁾. Specifically, in nineteen European countries, their increased availability between 1991 and 2008 was associated with increased obesity⁽Reference Monteiro, Moubarac and Levy⁸⁴⁾. The authors concluded that ‘A significant positive association was found between national household availability of ultra-processed foods and national prevalence of obesity among adults…’ However, further analyses of their data showing UPF_n availability by country does not show strong concordance with obesity data from the Organisation for Economic Co-operation and Development^{(85, 86)}. Table 4 compares a few countries with the high and low availability of UPF_n and obesity percentages. Simple associational data⁽Reference Monteiro, Moubarac and Levy⁸⁴⁾ fail to consider Food and Agriculture Organization data documenting increased energy consumed over that same time period⁽Reference Roser and Ritchie⁸⁷⁾.

Table 4. UPF_n Availability and obesity in selected countries (2008)

UPF_n, Ultraprocessed foods NOVA.⁽Reference Monteiro, Moubarac and Levy⁸⁴⁾

OECD, Organisation for Economic Co-operation and Development.^{(85, 86).}

Studies associating UPF_n with obesity had differing outcomes if they were adjusted for other contributors to obesity. Findings from the 2008 to 2009 Brazilian Dietary Survey showed that those in the quintile eating the most UPF_n, compared those eating the least, had higher risks of overweight (OR = 1·26) or obesity (OR = 1·98)⁽Reference Louzada, Baraldi and Steele⁸⁸⁾. However, it also showed that energy intakes for the higher quintile were 1255 kJ (300 kcal) more than for the lowest quintile⁽Reference Costa Louzada, Martins and Canella⁷⁾. This begs the question about adjusting for energy and whether the cause is more energy consumed or UPF_n. Findings were similar from Spanish University of Navarra cohort, where those in the highest, v. lowest, quartile of UPF_n consumption (three NOVA categories, not four) had a hazard risk for obesity of 1·26⁽Reference Mendonça, Pimenta and Gea^89, Reference Mendonça, Lopes and Gea⁹⁰⁾. However, there was no relationship between UPF_n and weight in the UK's National Diet and Nutrition Survey (2008–12; n 2174), after adjusting for other causes of obesity. This study did show that diets high in PCI_n were associated with body weight, indicating that food prepared at home may not stem the rise in obesity⁽Reference Monteiro, Moubarac and Levy⁸⁴⁾.

Fortified foods

All foods with added nutrients are UPF_n. However, data support the positive impact of enrichment and fortification. In the USA their use means that fewer than 12% of the US population fall below the estimated average requirement for thiamin, riboflavin, folate, iron and vitamin B₆⁽Reference Weaver, Dwyer and Fulgoni^17, Reference Fulgoni, Keast and Bailey⁶⁶⁾. For thiamin, 49% meet the estimated average requirement without fortificants, but 96% with them; for folate 12% without and 89% with them⁽Reference Fulgoni, Keast and Bailey⁶⁶⁾. Avoidance of folate-fortified grains in women the year prior to conception (as part of low carbohydrate or gluten/grain-free diets) was associated with a 30% increased risk of spina bifida and anencephaly in the infants⁽Reference Desrosiers, Siega-Riz and Mosley¹⁰³⁾. Thus, questionable placement of some foods into various categories and recommending the avoidance of all foods designated as UPF_n may not be sound dietary advice and may carry risks.

Ultra-processed foods, grain foods and body weight

Most grain-based foods are listed as UPF_n. Many eat too many grain servings, especially grain-based desserts or snacks and most fail to ingest recommended levels of wholegrain and fibre^{(80, 104–}Reference Cohen, Sturm and Lara¹⁰⁶⁾. Excess consumption of grain-based desserts and snacks may be associated with weight. However, avoidance of wholegrain and high-fibre bread and cereals because they are deemed UPF_n, may not address weight concerns. In the Physicians Health Study, those who ate one or more servings of whole and refined grain cereals daily, compared with those who ate less, were associated with lower risk of increasing BMI over time⁽Reference Bazzano, Song and Bubes¹⁰⁷⁾. Adolescents in the European HELENA cohort who were daily RTEC consumers, either whole grain or refined, had an OR of being overweight, 0·43 compared with non-consumers⁽Reference Michels, De Henauw and Breidenassel¹⁰⁸⁾. Similar findings have been shown in Australian children and adults⁽Reference Fayet-Moore, Petocz and McConnell^109, Reference Fayet-Moore, Kim and Sritharan¹¹⁰⁾. Designation of RTEC and bread as PF_n/UPF_n may decrease wholegrain, fibre and nutrient intakes and may not address the obesity problem⁽Reference Ludwig, Hu and Tappy¹¹¹⁾.

Added sugars, flavoured milk, nutrients and obesity

Flavoured milk and yoghurts are categorised as UPF_n. However, children consuming flavoured, v. unflavoured, milk have higher calcium and nutrient intakes and lower obesity risks⁽Reference Fayet-Moore^112, Reference Murphy, Douglass and Johnson¹¹³⁾. Initiatives to eliminate flavoured milk in schools made no difference in added sugars consumption. However, there was a significant drop in overall milk and calcium consumption⁽Reference Nicklas, O'Neil and Fulgoni^114, Reference Hanks, Just and Wansink¹¹⁵⁾ because flavoured milk drinkers consumed more milk. Avoidance of flavoured milk may do little to address obesity and may reduce nutrient intake⁽Reference Fayet-Moore^112, Reference Murphy, Douglass and Johnson¹¹³⁾.

Ultra-processed foods and other foods

Designating foods e.g. infant formulas, supplemental foods, lactose- and gluten-free foods, as UPF_n might cause avoidance by those who need these⁽Reference Ortega, Jiménez Ortega and Perea Sánchez^116–Reference Schultz, Roupas and Wiechula¹¹⁸⁾. Avoidance of any of those foods might do little to address rising rates of obesity and may not improve health.

Safety

Techniques and equipment for safe food handling are required to use MPF_n, especially as many outbreaks are linked to these foods⁽Reference Evans and Redmond^145–149). PF_n and MPF_n (without additives and preservatives) may not only have shorter shelf lives but also may pose a greater risk because ‘hurdle’ technologies and additives that inhibit microbial growth and maintain safety are not used⁽Reference Singh and Shalini¹⁵⁰⁾.

Infant formulas are designated as UPF_n. While breastfeeding is optimal, safe options are needed where this is not possible. Home-prepared formulas not only carry risks of nutritional imbalances, they have documented food safety risks⁽Reference Reece^{151, 152)}.