Dietary Guidelines Meet NOVA: Developing a Menu for A Healthy Dietary Pattern Using Ultra-Processed Foods

What should I eat today? Evidence, guidelines, dietary patterns and consumer's behavior

Over the past century, dietary recommendations emphasizing food patterns as means to deliver essential nutrients have garnered widespread acceptance. The necessity for foods supplying vital nutrients and energy throughout various life stages requires the involvement of local resources and cultural practices to prevent nutrient deficiency diseases. Since the 1980s, dietary guidelines aimed at adverting chronic diseases have relied on epidemiological research to predict which dietary patterns correlate with reduced risk of chronic disease or links to health outcomes. Dietary guidelines have been broad, typically recommending avoiding excess or deficiency of single nutrients. Efforts to fine-tune these recommendations face challenges due to a scarcity of robust scientific data supporting more specific guidance across the life cycle. Consumers have become skeptical of dietary guidelines, because media coverage of new studies is often in conflict with accepted nutrition dogma. Indications to align individual and planet's health have been issued supporting the concept of sustainable dietary patterns. Whether we really have a science-based databank to support dietary guidelines is still a matter of ongoing debate, as presented in this paper.

Toward a science-based classification of processed foods to support meaningful research and effective health policies

Processed foods have been part of the American diet for decades, with key roles in providing a safe, available, affordable, and nutritious food supply. The USDA Food Guides beginning in 1916 and the US Dietary Guidelines for Americans (DGA) since 1980 have included various types of commonly consumed processed foods (e.g., heated, fermented, dried) as part of their recommendations. However, there are multiple classification systems based on "level" of food processing, and additional evidence is needed to establish the specific properties of foods classified as "highly" or "ultra"-processed (HPF/UPFs). Importantly, many foods are captured under HPF/UPF definitions, ranging from ready-to-eat fortified whole grain breakfast cereals to sugar-sweetened beverages and baked goods. The consequences of implementing dietary guidance to limit all intake of foods currently classified as HPF/UPF may require additional scrutiny to evaluate the impact on consumers' ability to meet daily nutrient recommendations and to access affordable food, and ultimately, on health outcomes. Based on a meeting held by the Institute for the Advancement of Food and Nutrition Sciences in May 2023, this paper provides perspectives on the broad array of foods classified as HPF/UPFs based on processing and formulation, including contributions to nutrient intake and dietary patterns, food acceptability, and cost. Characteristics of foods classified as UPF/HPFs are considered, including the roles and safety approval of food additives and the effect of food processing on the food matrix. Finally, this paper identifies information gaps and research needs to better understand how the processing of food affects nutrition and health outcomes.

Ultra-processed foods and food additives in gut health and disease

Ultra-processed foods (UPFs) and food additives have become ubiquitous components of the modern human diet. There is increasing evidence of an association between diets rich in UPFs and gut disease, including inflammatory bowel disease, colorectal cancer and irritable bowel syndrome. Food additives are added to many UPFs and have themselves been shown to affect gut health. For example, evidence shows that some emulsifiers, sweeteners, colours, and microparticles and nanoparticles have effects on a range of outcomes, including the gut microbiome, intestinal permeability and intestinal inflammation. Broadly speaking, evidence for the effect of UPFs on gut disease comes from observational epidemiological studies, whereas, by contrast, evidence for the effect of food additives comes largely from preclinical studies conducted in vitro or in animal models. Fewer studies have investigated the effect of UPFs or food additives on gut health and disease in human intervention studies. Hence, the aim of this article is to critically review the evidence for the effects of UPF and food additives on gut health and disease and to discuss the clinical application of these findings.

Type and timing of ultra-processed foods consumption and its association with dietary intake and physical activity in women with obesity living in poverty

BACKGROUND

The present study aimed to investigate the type and timing of ultra-processed foods (UPF) consumption and its association with dietary intake (DI) and physical activity (PA) in women with obesity living in poverty.

METHODS

A cross-sectional study was employed. Obesity was defined by at least two criteria (body mass index, waist circumference or % fat mass). Poverty was defined as the three lowest classes of the Brazilian Economic Classification Criterion. PA was measured with triaxial accelerometers and DI was assessed with three 24-h dietary recalls. Foods were categorised according to the NOVA classification, with UPF classified into five subgroups, as well as the timing of consumption into six meals.

RESULTS

In total, 56 adult women were included. Overall energy intake was 1653.21 (503.22) kcal/day. UPF intake was 21.62% (11.94%) kcal/day, being higher at breakfast (4.91% kcal/day), afternoon snack (5.39% kcal/day) and dinner (5.01% kcal/day). Only UPF subgroup 4 (sandwich biscuits, sweets, or treats) showed a positive association with energy intake (β = 54.40 [27.6, 81.10] kcal/day) and a negative association with protein intake (β = -0.31% [-0.48%, -0.14%] kcal/day). UPF consumption in morning (β = -0.41% [-0.79%, -0.02%] kcal/day) and afternoon (β = -0.18% [-0.33%, -0.04%] kcal/day) snacks was associated with lower protein intake. Furthermore, lunchtime UPF consumption was positively associated with walking time (β = 0.16% [0.02%; 0.30%]) and steps/hour (β = 8.72 [1.50; 15.94] steps/h).

CONCLUSIONS

Women with obesity living in poverty consume more UPF during breakfast, afternoon snack and dinner. Physical activity is positively associated with UPF consumption at lunch. UPF, such as sandwich biscuits, sweets or treats, contribute to increasing energy intake and reducing protein intake.

Nutrients or processing? An analysis of food and drink items from the UK National Diet and Nutrition Survey based on nutrient content, the NOVA classification and front of package traffic light labelling

UK front of package labelling (FOPL) informs consumers on the nutrient content of food. However, FOPL does not consider food processing, and with the UK government being urged to act on ultra-processed food (UPF), whether UPF should be added to FOPL is unclear. This study compared food and drink in the UK National Diet and Nutrition Survey (NDNS) Intake24 database based on FOPL, nutrient content and NOVA classification, to understand whether UPF are covered by dietary recommendations for foods high in fat, salt and sugar. NDNS items were coded into minimally processed food (MPF), processed culinary ingredients, processed food and UPF according to the NOVA classification and FOPL traffic lights. UPF contained greater energy, fat, saturated fat (SF), total sugar (TS) and salt than MPF. UPF had a greater odds of containing red FOPL and an unhealthier overall FOPL score (OR:4·59 (95 % CI: 3·79, 5·57); OR:7·0 (95 % CI: 6·1, 8·2), respectively) and lower odds of containing green FOPL (OR:0·05 (95 % CI: 0·03, 0·10)), compared with MPFs. For items with no red FOPL, UPF still contained greater energy, fat, SF, TS and salt than MPF. However, several UPF have healthier FOPL scores. UPF had an unhealthier nutritional profile and FOPL score than MPF. For items with no red FOPL, UPF still had an unhealthier profile than MPF, with a higher energy density. Importantly, not all UPF were unhealthy according to FOPL. These results indicate partial overlap between FOPL, nutrient content and NOVA classification of UK food and drink products, with implications for UK food and drink labelling.

The use of food processing terminology in Australian news media: a content analysis

OBJECTIVE

This study aims to determine whether ultra-processed foods (UPFs) are being discussed in news media in Australia and whether this terminology, as described in the NOVA system, is being applied accurately.

DESIGN

Interpretive content analysis of online and print media articles that mentioned UPFs from 2009 to 2023 in Australia.

SETTING

Australia.

PARTICIPANTS

Online and print media articles.

RESULTS

A total of two hundred ninety-eight Australian media articles were captured. A substantial increase in the number of UPF articles was observed between 2017-2019 and 2021-2023. The UPF concept was inaccurately explained or defined in 32 % of the articles and was frequently used interchangeably with other descriptors, such as 'highly or heavily processed food', 'junk food', 'unhealthy food', 'packaged food' and 'discretionary food'. Most of the articles had a health focus; however, sustainability interest increased, particularly in the past 18 months.

CONCLUSIONS

UPFs are increasingly being discussed in news media in Australia; however, the concept is still incorrectly presented in over a third of articles. This highlights the importance of improving the literacy about UPFs to ensure that messages are communicated in a way that is salient, accessible and accurate.

Ultra-Processed Foods-Dietary Foe or Potential Ally?

The prevalence of non-communicable diseases (NCDs) has steadily increased in the United States. Health experts attribute the increasing prevalence of NCDs, in part, to the consumption of ultra-processed foods (UPFs) based on epidemiological observations. However, no definitive evidence of causality has been established. Consequently, there is an ongoing debate over whether adverse health outcomes may be due to the low nutrient density per kilocalorie, the processing techniques used during the production of UPFs, taste preference-driven overconsumption of calories, or unidentified factors. Recognizing that "the science is not settled," we propose an investigative process in this narrative review to move the field beyond current controversies and potentially identify the basis of causality. Since many consumers depend on UPFs due to their shelf stability, affordability, availability, ease of use, and safety from pathogens, we also suggest a paradigm for guiding both the formulation of UPFs by food designers and the selection of UPFs by consumers.

Ultra-processed Food and Obesity: What Is the Evidence?

PURPOSE OF REVIEW

Obesity is a growing global healthcare concern. A proposed driver is the recent increase in ultra-processed food (UPF) intake. However, disagreement surrounds the concept of UPF, the strength of evidence, and suggested mechanisms. Therefore, this review aimed to critically appraise the evidence on UPF and obesity.

RECENT FINDINGS

Observational studies demonstrate positive associations between UPF intake, weight gain, and overweight/obesity, more clearly in adults than children/adolescents. This is supported by high-quality clinical data. Several mechanisms are proposed, but current understanding is inconclusive. Greater UPF consumption has been a key driver of obesity. There is a need to change the obesogenic environment to support individuals to reduce their UPF intake. The UPF concept is a novel approach that is not explained with existing nutrient- and food-based frameworks. Critical analysis of methodologies provides confidence, but future observational and experimental research outputs with greater methodological rigor will strengthen findings, which are outlined.

The Human Interference Scoring System (HISS): A New Tool for Quantifying Food Quality Based on Its Level of Processing

The Human Interference Scoring System (HISS) is a novel food-based diet-quality-classification system based on the existing NOVA method. HISS involves food and fluid allocation into categories from digital imagery based on food processing levels, followed by meal plan analysis using food-servings quantification. The primary purpose of this work was to evaluate the reliability of HISS. Trained nutrition professionals analyzed digital photographs from five hypothetical 24 h food recalls and categorized foods into one of four HISS categories. A secondary purpose was to assess the nutrient composition of the food recalls and other selected foods from the HISS categories. Participants effectively categorized foods into HISS categories, with only minor discrepancies noted. High inter-rater reliability was observed in the outer HISS categories: unprocessed and ultra-processed foods. Ultra-processed items consistently displayed elevated energy, carbohydrates, and sugar compared to unprocessed foods, while unprocessed foods exhibited notably higher dietary fiber. This study introduces the HISS as a potentially useful tool for quantifying a food-quality-based system using digital-photography-based assessments. Its high inter-rater reliability and ability to capture relationships between food processing levels and nutrient composition make it a promising method for assessing dietary habits and food quality.

Increased consumption of ultra-processed foods during pregnancy is associated with sociodemographic, behavioral, and obstetric factors: A cohort study

A diet based on ultra-processed food (UPF) does not meet nutritional needs, especially during pregnancy. The aim of this study is to assess the change in UPF consumption from preconception to pregnancy and associated factors. Our hypothesis is that women tend to adopt a healthier eating pattern during pregnancy, decreasing the intake of UPF and increasing the intake of unprocessed/minimally processed foods. A prospective cohort study with 326 participants was carried out from 2016 to 2019 in 2 health units in Rio de Janeiro, Brazil. Pregestational food consumption assessed using the food frequency questionnaire in the prenatal interview in women up to 20 gestational weeks and gestational consumption in the interview 2 months after delivery. Food items classified according to the NOVA system. For the mean variation from preconception to gestational UPF consumption, we used the generalized estimating equations model with linear distribution. Control of confounding variables was based on the literature on factors associated with UPF consumption, using a 3-level hierarchical model. The proportion of UPF energy consumption was 28.9% in preconception and 33% during pregnancy. Older and more educated women had a lower mean variation in the consumption of UPF during the pregnancy. A higher average consumption of UPF observed among women physically inactive before pregnancy, who smoked during pregnancy, were multiparous, and with had a low pregestational weight. These results reflect similar behavior to that of the general population, aggravated by a significant increase during pregnancy. However, older and more educated women and those with healthy behaviors showed lower UPF intake in pregnancy.

Ultra-processed and fast food consumption, exposure to phthalates during pregnancy, and socioeconomic disparities in phthalate exposures

BACKGROUND

Consuming ultra-processed foods may increase exposure to phthalates, a group of endocrine disruptors prevalent in food contact materials.

OBJECTIVES

Investigate associations between ultra-processed food intake and urinary phthalates during pregnancy, and evaluate whether ultra-processed foods mediate socioeconomic disparities in phthalate exposures.

METHODS

In a socioeconomically diverse sample of 1031 pregnant women from the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) Study in the urban South, the Block Food Frequency Questionnaire was administered and urinary phthalate metabolites were measured in the second trimester. Linear regressions modeled associations between phthalates and overall ultra-processed food consumption, individual ultra-processed foods, and exploratory factor analysis dietary patterns. Causal mediation analyses examined whether ultra-processed food intake mediates relationships between socioeconomic disparities and phthalate exposures.

RESULTS

Ultra-processed foods constituted 9.8-59.0 % (mean = 38.6 %) of participants' diets. 10 % higher dietary proportion of ultra-processed foods was associated with 13.1 % (95 %CI: 3.4 %-22.9 %) higher molar sum concentrations of di(2-ethylhexyl) phthalate metabolites (ΣDEHP). 10 % higher consumption of minimally-processed foods was associated with lower ΣDEHP (10.8 %: 3.4 %-22.9 %). Ultra- and minimally-processed food consumption were not associated with non-DEHP metabolites. Standard deviation higher consumptions of hamburger/cheeseburger, French fries, soda, and cake were associated with 10.5 % (4.2 %-17.1 %), 9.2 % (2.6 %-16.2 %), 7.4 % (1.4 %-13.6 %), and 6.0 % (0.0 %-12.4 %), respectively, higher ΣDEHP. Exploratory factor analysis corroborated positive associations of processed food with ΣDEHP, and uncovered a healthy dietary pattern associated with lower urinary ΣDEHP, mono(2-ethyl-5-hydroxyhexyl) (MEHHP), mono(2-ethyl-5-carboxypentyl) (MECPP), mono(2-carboxymethylhexyl) (MCMHP), and mono-isononyl (MINP) phthalates. Significant indirect effects indicated that lower income and education levels were associated with 1.9 % (0.2 %-4.2 %) and 1.4 % (0.1 %-3.3 %) higher ΣDEHP, respectively, mediated via increased ultra-processed food consumption.

CONCLUSIONS

Consumption of ultra-processed foods may increase exposure to phthalates. Policies to reduce dietary phthalate exposures from food packaging and processing are needed, as socioeconomic barriers can preclude dietary recommendations as a sole means to reduce phthalate exposures.

Perspective: A Research Roadmap about Ultra-Processed Foods and Human Health for the United States Food System: Proceedings from an Interdisciplinary, Multi-Stakeholder Workshop

Our objective was to convene interdisciplinary experts from government, academia, and industry to develop a Research Roadmap to identify research priorities about processed food intake and risk for obesity and cardiometabolic diseases (CMD) among United States populations. We convened attendees at various career stages with diverse viewpoints in the field. We held a "Food Processing Primer" to build foundational knowledge of how and why foods are processed, followed by presentations about how processed foods may affect energy intake, obesity, and CMD risk. Breakout groups discussed potential mechanistic and confounding explanations for associations between processed foods and obesity and CMD risk. Facilitators created research questions (RQs) based on key themes from discussions. Different breakout groups convened to discuss what is known and unknown for each RQ and to develop sub-RQs to address gaps. Workshop attendees focused on ultra-processed foods (UPFs; Nova Group 4) because the preponderance of evidence is based on this classification system. Yet, heterogeneity and subjectivity in UPF classification was a challenge for RQ development. The 6 RQs were: 1) What objective methods or measures could further categorize UPFs, considering food processing, formulation, and the interaction of the two? 2) How can exposure assessment of UPF intake be improved? 3) Does UPF intake influence risk for obesity or CMDs, independent of diet quality? 4) What, if any, attributes of UPFs influence ingestive behavior and contribute to excess energy intake? 5) What, if any, attributes of UPFs contribute to clinically meaningful metabolic responses? 6) What, if any, external environmental factors lead people to consume high amounts of UPFs? Uncertainty and complexity around UPF intake warrant further complementary and interdisciplinary causal, mechanistic, and methodological research related to obesity and CMD risk to understand the utility of applying classification by degree of processing to foods in the United States.