The Reporting of “What We Eat in America” Nutrient Intake Data in the Scientific Literature: A Scoping Review

Abstract

Background:

The United States national dietary surveillance program, What We Eat in America (WWEIA), NHANES, quantifies intake of nutrients, food, and other components across ages and life stages for the noninstitutionalized population of the United States. The use of this continuously collected, nationally representative, publicly available data has never been quantified.

Objectives:

The aim of this study was to determine the extent to which nutrient data from WWEIA, NHANES are reported in the peer-reviewed, scientific literature.

Methods:

Scientific studies were identified using searches in MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and Cochrane Central Register of Controlled Trials. Inclusion criteria required studies to be peer-reviewed, published in English between 2013 and 2023, and report ≥1 nutrients using WWEIA, NHANES data from any cycle of the continuous NHANES (1999–2020). Screening and data extraction were conducted by 2 independent reviewers, with conflict resolution by a third reviewer.

Results:

Of 12,589 screened studies, 2203 met the inclusion criteria. The number of included studies by publication year increased nearly 4-fold over the study period, and the studies were authored by researchers located in 60 countries. The most frequently reported nutrients were energy (n = 1724; 78%), total saturated fatty acids (n = 918; 42%), sodium (n = 828; 38%), protein (n = 748; 34%), total polyunsaturated fatty acids (n = 745; 34%), total monounsaturated fatty acids (n = 702; 32%), dietary fiber (n = 707; 32%), total fat (n = 682; 31%), and carbohydrates (n = 598; 27%). Fifty-seven percent of studies (n = 1266) reported ≥1 mineral, and 35% (n = 771) reported ≥1 vitamin. Nearly one-third of studies used 1 of 38 unique dietary indices (n = 677; 31%).

Conclusions:

The use of WWEIA, NHANES data in the scientific literature is prominent and has grown over time. The widespread use of this national dietary surveillance data demonstrates their importance for continued nutrition research, surveillance, and policy.

Introduction

Nutrients in foods are the foundation for national dietary surveillance. The USDA determines the composition of the United States food supply, and as such has been the source of characterizing foods based on their nutrient content [1]. For >2 decades, the NHANES has been conducted without interruption and is the federal government’s premier program for assessing the health and nutritional status of the population [2]. The dietary interview component of NHANES is titled What We Eat in America (WWEIA) and is conducted with NHANES participants through 2 nonconsecutive 24-h dietary interviews [3]. These interviews are conducted by trained interviewers using USDA’s 5-step Automated Multiple-Pass Method (AMPM) [3]. The AMPM collects foods, beverages, and their amounts consumed over the previous day and provides the means, through a separate database, for estimating the quantities of energy, nutrients, and other food components from those foods.

The basis for the nutrient values is the Food and Nutrient Database for Dietary Studies (FNDDS), an application database created, updated, and maintained by the USDA. FNDDS is designed specifically for analyzing dietary intakes from WWEIA and NHANES, making the AMPM and FNDDS interconnected components of national surveillance. AMPM questions and response options are the basis for the foods and beverages listed in the FNDDS. In addition to the nutrients and food components in the foods and beverages consumed in the United States, FNDDS contains extensive defined reference data for all nutrient values. Extensive details about FNDDS and AMPM have been reported elsewhere [4,5].

To our knowledge, the widespread use of nutrient intake data from the continuous WWEIA, NHANES (1999–present) in research has never been quantified or assessed. A scoping review was conducted to determine the extent to which nutrient data from WWEIA and NHANES are reported in the peer-reviewed, scientific literature.

Methods

This scoping review included all nutrients and food components (hereinafter referred to solely as nutrients) that are estimated in FNDDS, except for added vitamin E and added vitamin B12, which were not distinguished from vitamin E and vitamin B12 in this review. The review was conducted employing the methodological framework presented by Arksey and O’Malley [6] as updated by Levac et al. [7] and clarified by Munn et al. [8]. This approach was chosen because the aim of the review was to examine the extent, nature, and range of research activity in this area rather than to answer a narrow research question [8]. The PRISMA Extension for Scoping Reviews checklist [9] was followed to report this study (Supplemental Table 1). There were 5 stages to the review: 1) formulation of the research question; 2) determination of inclusion and exclusion criteria; 3) systematic study selection; 4) data extraction and analysis; and 5) narrative description of results.

Inclusion and exclusion criteria

The Population, Concept, and Context framework was used to determine the elements of the inclusion and exclusion criteria [10]. WWEIA, NHANES is designed to assess the health and nutritional status of the United States population [2]. As a result, publications assessing the United States population as a whole or any of its subpopulations using WWEIA, NHANES data were included in this scoping review. The NHANES sample design requirements defined the population [11].

The concept of interest was the reporting of a nutrient using WWEIA, NHANES data in the peer-reviewed scientific literature. Nutrients are utilized in a variety of ways, such as in the analysis of dietary intake and associations with health outcomes, in calculations of dietary indices, as reference nutrient levels for comparative studies, and in estimating population intakes. This review did not limit any applications of nutrient analyses in studies using WWEIA, NHANES data, provided the analysis utilized dietary intakes. The review encompassed any context, setting, discipline, or field that reported ≥1 nutrients from WWEIA, NHANES. Studies that focused exclusively on intakes of dietary supplements were excluded.

Types of evidence sources

Studies included in the review were limited to peer-reviewed, English-language studies published in the scientific literature between January 2013 and October 2023 that reported ≥1 nutrients using WWEIA, NHANES data from any cycle of the continuous NHANES (1999–2020). First January, 2013, was selected as the start of the search to ensure a minimum 10-y period of coverage and a large, recent body of literature. Eighteenth October, 2023, served as the end date because that is the date when all the searches were finalized. Editorials, perspectives, commentaries, and opinion articles; narrative, systematic, and scoping reviews; author corrections; studies not published in peer-reviewed journals; and conference proceedings and abstracts were all excluded.

Systematic study selection

Working with a librarian experienced in systematic searches, comprehensive literature searches for studies meeting the inclusion criteria were conducted in multiple databases, starting with the MEDLINE database on the Ovid platform. A search query that included a combination of free-text terms and subject headings from the National Library of Medicine’s Medical Subject Headings controlled vocabulary [12] was developed using an iterative process. The initial iteration included clauses that focused on the source of the data or used terms related to dietary intake assessment, whereas other clauses focused on individual nutrients. Results from this search were reviewed to identify the query’s retrieval performance, specifically the extent to which relevant studies were not retrieved (recall issue) or the extent to which irrelevant studies were retrieved (precision issue) [13].

On the basis of these results, a set of alternative queries were generated by applying a range of transformations to the original query, including operator substitution (e.g., interchanging AND and OR, adding or modifying proximity operators, and adding or removing field restrictions), query expansion (i.e., adding new clauses to the query), and query reduction (i.e., removing clauses from the query). Each alternative query was evaluated by subject-matter experts based on recall and precision until a final MEDLINE query was selected (Supplemental Table 2).

Subsequent searches were conducted in Cumulative Index to Nursing and Allied Health Literature, Web of Science, and The Cochrane Central Register of Controlled Trials. For searches in each additional database, adjustments were made to the MEDLINE search query to account for differences in syntax and controlled vocabularies. A hand search was not conducted because of the large volume of studies identified from the database searches. The gray literature was not searched, as this review focused on peer-reviewed studies.

Studies were assessed for eligibility using a 2-step process. First, results from each of the database searches were imported into Covidence, a web-based software program for managing and analyzing data in literature reviews [14]. After duplicates were removed, 2 reviewers (any combination of KMK, AWW, MKH, SBC, AEC, DCM, and WJM) independently screened each title and abstract for potential eligibility against the inclusion and exclusion criteria. Conflicts in determining eligibility were resolved via discussion between the 2 reviewers. If consensus could not be reached, a third reviewer independently resolved any remaining conflicts.

Next, full texts of all studies that appeared to meet the eligibility criteria and those that did not contain enough information during the preceding step to determine eligibility were uploaded into Covidence and assessed for eligibility using the same process described above. Reasons for a decision to exclude a study at this stage were documented.

Data extraction, processing, and analysis

A standardized data extraction form was developed and refined in Covidence by the full panel of reviewers and piloted using a subset of included articles by 2 subject matter experts (KMK and ACP). Data extraction from each included study was subsequently conducted independently by 2 reviewers (any combination of KMK, AWW, MKH, SBC, AEC, DCM, and WJM) using the Covidence data extraction form, with a third reviewer independently resolving any conflicts. To standardize the data collection process, a data extraction manual was developed and used by all the reviewers.

For each of the studies, the following data parameters were extracted: the year the study was published, the nutrient(s) reported in the study, countries reflected in the author affiliations, the names of any dietary indices constructed from ≥1 nutrient used by the researchers in their analysis, characteristics of the study sample such as ages, and whether the data were linked to mortality data.

Analysis of the data included the calculation of the number and percentage of included publications that reported each nutrient and the distribution of included publications by publication year. To accurately capture the reporting of nutrients, publications that reported a nutrient as well as publications that reported a nutrient through the use of a dietary index were included in the nutrient calculations. Analysis also included the calculation of the number and percentage of publications that included ≥1 author from each continent, the number of publications that included ≥2 authors from different countries, and the number of publications that reported nutrients using ≥1 dietary index. Different variations of a common index were reported together.

Article management and data extraction were performed in Covidence. Extracted data were exported first to Microsoft Excel for cleaning and initial postprocessing and then to SAS software, version 9.4 (SAS Institute, Inc) for additional postprocessing. All analyses were conducted using SAS software or Microsoft Excel, and all figures and tables were created using Microsoft Excel. This scoping review was a secondary research study involving published research articles, not people or animals. Therefore, no ethical approval was required.

Results

Search results

Figure 1 shows the PRISMA flow diagram for the screening process. A total of 12,589 studies were identified by the search query. After removal of 5781 duplicates, 6808 studies were screened on the basis of titles and abstracts, leaving 2763 for full-text review. Of these, 2203 met the inclusion criteria and were included in the scoping review (Supplemental Table 3).

FIGURE 1.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram for scoping review of published research studies reporting nutrients using What We Eat in America (WWEIA), National Health and Nutrition Examination Survey (NHANES), January 1, 2013–October 18, 2023.

Publication year

The number of publications by year is shown in Figure 2. In general, the number rose nearly 4-fold over the review period from 106 studies in 2013 to 414 studies in 2022. Although the 375 studies published in 2023 are fewer than those published in 2022, this number reflects only those studies published between 1 January and 18 October, 2023, the end of the literature search period.

FIGURE 2.

Number of publications (n = 2203) reporting nutrients from What We Eat in America (WWEIA), National Health and Nutrition Examination Survey (NHANES) data by year, 2013–2023. *Publications for 2023 reflect a truncated year ending October 18, 2023.

Reported nutrients

Within the 2203 publications included in this scoping review, energy was most frequently reported, appearing in 1724 (78%) publications (Table 1). Other frequently reported nutrients appearing in at least 1-quarter of publications were total SFAs, sodium, protein, total PUFAs, total dietary fiber, total MUFAs, total fat, and carbohydrates. Of the 63 nutrients listed in Table 1, 42 were utilized in >100 publications, 26 in >300 publications, and 11 in >500 publications. The least frequently reported nutrients included all the individual SFAs and MUFAs and theobromine, all of which appear individually in <40, or ~2%, of all publications. At least 1 mineral was reported in 57% of studies (n = 1266), with the most frequently reported being sodium (n = 828, 38%). Among the vitamins (which included each of 4 measures for folate), ≥1 was reported in 35% of studies (n = 771), with the most frequently reported being vitamin C (n = 491, 22%).

TABLE 1.

Number and percentage of publications (n = 2203) reporting nutrients from WWEIA, NHANES data by nutrient, 2013–2023.

Nutrient	Number of Publications	Percentage of Publications
Food energy (kcal)	1724	78
Protein (g)	748	34
Carbohydrate (g)	598	27
Fat, total (g)	682	31
Alcohol (g)	511	23
Sugars, total (g)	262	12
Dietary fiber, total (g)	707	32
Water (g)	121	5
Saturated fatty acids, total (g)	918	42
Monounsaturated fatty acids, total (g)	702	32
Polyunsaturated fatty acids, total (g)	745	34
Cholesterol (mg)	357	16
Individual fatty acids
Saturated fatty acids
4:0 Butyric acid (g)	31	1
6:0 Caproic acid (g)	32	1
8:0 Caprylic acid (g)	32	1
10:0 Capric acid (g)	33	1
12:0 Lauric acid (g)	38	2
14:0 Myristic acid (g)	36	2
16:0 Palmitic acid (g)	39	2
18:0 Stearic acid (g)	38	2
Monounsaturated fatty acids:
16:1 Palmitoleic acid (g)	34	2
18:1 Oleic acid (g)	37	2
20:1 Gadoleic acid (g)	33	1
22:1 Erucic/citoleic acid (g)	32	1
Polyunsaturated fatty acids:
18:2 Linoleic acid (g)	203	9
18:3 Linolenic acid (g)	216	10
18:4 Parinaric acid (g)	53	2
20:4 Arachidonic acid (g)	183	8
20:5n–3 Eicosapentaenoic acid (EPA) (g)	276	13
22:5n–3 Docosapentaenoic acid (DPA) (g)	69	3
22:6n–3 Docosahexaenoic acid (DHA) (g)	278	13
Vitamin A as retinol activity equivalents (μg)	434	20
Retinol (μg)	48	2
Carotenoids
Carotene, alpha (μg)	89	4
Carotene, beta (μg)	231	10
Cryptoxanthin, beta (μg)	80	4
Lycopene (μg)	91	4
Lutein + zeaxanthin (μg)	87	4
Vitamin E as alpha-tocopherol (mg)	409	19
Vitamin D (D2 + D3) (μg)	454	21
Vitamin K as phylloquinone (μg)	136	6
Vitamin C (mg)	491	22
Thiamin (mg)	323	15
Riboflavin (mg)	330	15
Niacin (mg)	317	14
Vitamin B6 (mg)	378	17
Folate, total (μg)	146	7
Folate (DFE) (μg)	158	7
Folic acid (μg)	189	9
Food folate (μg)	45	2
Vitamin B12 (μg)	379	17
Choline, total (mg)	120	5
Calcium (mg)	494	22
Iron (mg)	434	20
Magnesium (mg)	500	23
Phosphorus (mg)	224	10
Potassium (mg)	364	17
Sodium (mg)	828	38
Zinc (mg)	402	18
Copper (mg)	164	7
Selenium (μg)	330	15
Caffeine (mg)	279	13
Theobromine (mg)	27	1

Abbreviations: DFE, dietary folate equivalents; g, grams; kcal, kilocalories; μg, micrograms; mg, milligrams; NHANES, National Health and Nutrition Examination Survey; WWEIA, What We Eat in America.

Author continent affiliations

Researchers in 60 countries located on 6 continents contributed to research reporting nutrients published during the review period. Eighteen percent of the publications (n = 396) had authors from >1 country. Figure 3 depicts author affiliation by continent/region, with 64% of the studies (n = 1405) having ≥1 author affiliation in North America, 37% (n = 820) in Asia, 9% (n = 204) in Europe, 3% (n = 61) in South America, 2% (n = 54) in Oceania, and 1% (n = 22) in Africa.

FIGURE 3.

Percentage of publications (n = 2203) reporting nutrients from What We Eat in America (WWEIA), National Health and Nutrition Examination Survey (NHANES) data by continent, 2013–2023. Each percentage denotes publications with ≥1 author from that continent.

Dietary indices

Thirty-one percent (n = 677) of the included studies used 1 of 38 dietary indices, with >3-fold increase over 10 y. Table 2 reports the number of studies by index. The most frequently used indices were the USDA’s Healthy Eating Index (HEI) [15] and the Dietary Inflammatory Index [16]. The remaining indices were each reported in ≤5% of the included studies that used a dietary index.

TABLE 2.

Number of publications reporting nutrients from WWEIA, NHANES by dietary index, 2013–2023.

Dietary Index Name1	Publications2 (n = 677)
Healthy Eating Index	481
Dietary Inflammatory Index	123
Dietary Approaches to Stop Hypertension	36
Mediterranean Diet	33
Composite Dietary Antioxidant Index	13
Healthy Diet Score	12
Nutrient Rich Foods	12
Dietary Acid Load	9
Nutrition Index	3
Total Nutrient Index	3
Balanced Hybrid Nutrient Density Score	2
Dietary Antioxidant Quality Score	2
Dietary Oxidative Balance Score	2
Healthy Beverage Index	2
Low Carbohydrate Diet Score	2
Mean Adequacy Ratio	2
Antioxidant and Anti-Inflammatory Dietary Score	1
Diet Quality Score	1
Dietary Inadequacy/Insufficiency Score	1
Food Quality Index	1
French Nutri-Score	1
Health Star Rating	1
Healthy Diet Score	1
Low Carbohydrate Diet	1
Low Fat Diet Score	1
Meal Balance Index	1
Mean Excess Ratio	1
My Nutrition Index	1
Nestlé Nutrition Algorithm	1
Nutrient Profile Index	1
Nutri-Score	1
Nutritional Quality Index	1
Oxidative Balance Score	1
Probability of Adequate Nutrient intake based Diet quality index	1
Revised Children’s Diet Quality Index	1
Total Antioxidant Capacity	1
Total Nutrient Index	1
Vitamin C Equivalent Antioxidant Capacity	1

Abbreviations: NHANES, National Health and Nutrition Examination Survey; WWEIA, What We Eat in America.

¹Dietary indices utilized in each publication are identified in Supplemental Table 3.

²Sum of column exceeds 677 because some publications (n = 67) used >1 dietary index.

Other publication characteristics

Of the included studies, participants were limited to children aged ≤19 y in 14% (n = 311), to adults aged ≥20 y in 51% (n = 1120), and to both children and adults in 33% (n = 719). Additionally, in 9% (n = 194) of the included studies, WWEIA, NHANES data were linked to mortality data.

Discussion

To our knowledge, this is the first study to systematically describe the reporting of nutrients using a scoping review methodology, providing insights into the frequency with which national dietary surveillance data have been employed in the peer-reviewed scientific literature. The number of studies increased 4-fold across the 10-y review period and reflect authorship by researchers worldwide, with many studies having authors from ≥2 countries.

Attributes of WWEIA, NHANES data contributing to its utility in dietary intake research

Several key characteristics of WWEIA, NHANES data contribute to its utility in dietary intake research. The data are both nationally representative and comprehensive in scope, facilitating a wide range of assessments. For example, data on individual nutrients, individual foods, time and place of consumption, and source of foods are all available. In the latest WWEIA, NHANES release from 2021 to 2023, ~500 variables were included. These rich data have made possible a wide range of studies relating to food and nutrient intakes, national dietary patterns, and longitudinal trends in food choices among the United States population, to name a few. The curation of WWEIA, NHANES data is consistent across each 2-y release. WWEIA, NHANES data are clearly organized and accompanied by detailed documentation files and user guidelines. WWEIA, NHANES data are also publicly available and can be used with other NHANES variables as well as linked to external data sources such as National Death Index and Medicare.

Frequently reported nutrients

The frequently studied nutrients identified within this scoping review help to illustrate the focus of recent and possibly future nutrition research. They are also often associated with federal nutrition policies and programs, such as the Dietary Guidelines for Americans (DGA) [17] or food labeling requirements [18]. Surveillance of nutrient intake at the population level is a critical asset to furthering areas of research, supporting federal policies, and monitoring the nation’s health. The following sections discuss select nutrients that were highly reported and/or designated as a public health concern, as well as examples of research and federal policies that highlight the importance of continued national dietary intake surveillance.

Energy and select macronutrients

Energy was reported in over three-quarters of publications, and most macronutrients were reported in over a quarter of the publications. Of these, all are required on the nutrition facts panel apart from total PUFAs and MUFAs, which are voluntary [18].

The proportion of publications reporting energy intake far surpassed the reporting frequency of any other single nutrient by >30%. Energy is frequently studied because of its well-established linkages to body composition, chronic health conditions, and risk of disease [19]. In addition, energy intake is often used as a control variable in epidemiological studies to help isolate the effect of a dietary component of interest from the confounding effect of varying total energy intake [20,21].

Concerns regarding the overconsumption of calories have impacted several federal nutrition policies and programs. For example, in 2015, the United States Food and Drug Administration issued a final rule mandating establishments publish caloric content of their menu items to highlight energy intake [22]. Similarly, in 2016, the Nutrition Facts label was redesigned with a larger type size and bolded calorie content for easier visibility [23]. Access to accurate energy content of foods is particularly important for the DGA for constructing healthy dietary patterns [17]. Federal food programs also base requirements on caloric needs, such as nutrition standards for school meals [24]. Although energy intake and its effects on human health are well known, recent recommendations by the National Academies of Science highlight areas for continued research, including energy intake of specific vulnerable subpopulations such as women of reproductive age, diverse ethnic groups, and individuals with higher BMI [25].

Since its first publication in 1980, every iteration of the DGA has recommended a limited intake of total SFAs due to concerns with elevated blood cholesterol concentrations [26]. Since 1995, they have also recommended replacing intake of saturated fat with PUFAs and MUFAs [27]. Similarly, the American Heart Association recommends limiting saturated fat intake and increasing polyunsaturated fat intake [28]. Accordingly, much of the research on fat intake is centered around limiting SFAs and increasing intake of PUFAs and MUFAs.

Research on protein intake has been prominent for decades [29], with attention not only to total protein intake but also more recently to protein source [30]. Specifically, plant-based protein sources have been a focus around the world, with the United States, Brazil, Canada, and United Kingdom’s most recent dietary guidance emphasizing plant-based proteins such as beans and legumes [31-34]. Globally, consuming more plant-based protein has been encouraged in both the EAT-Lancet Commission’s 2019 report [35] and the FAO’s 2016 report [36].

Select micronutrients

Sodium was the most frequently reported micronutrient, appearing in nearly 40% of all publications. Along with sugars and saturated fats, sodium has been a public health focus in every edition of the DGA [17,26,27,37-42]. Much attention has been given to high sodium intake for its association with adverse health consequences, such as hypertension [43]. The Dietary Approaches to Stop Hypertension diet [44], which limits sodium intake, has been recommended by the American Heart Association to reduce hypertension risk [45].

In addition to supporting research efforts, continuous WWEIA, NHANES data collection of sodium intake at the population level has enabled the development and evaluation of several nutrition policies. Although the recommended level for chronic disease risk reduction is no more than 1200 to 2300 mg of sodium per day (depending on age) [46], the DGA 2020–2025 analyses of WWEIA, NHANES data show that the average sodium intake for individuals aged ≥1 y is ~3400 mg sodium per day [17]. In 2016, the FDA issued draft guidance [47] on voluntary sodium reduction targets for the food industry, which was finalized in 2021 [48]. Preliminary assessments have indicated that from 2010 to 2022, over half of packaged food and restaurant food categories showed decreases in their sodium content [49].

Folic acid intake has been a public health priority in the prevention of neural tube defects (NTDs) [50]. In 1998, the FDA mandated the fortification of folic acid in standardized enriched cereal-grain products because of low intake [51,52]. In establishing the fortification level, national dietary surveillance data played a crucial role. The FDA modeled food consumption data for the level of fortification in the target foods with consideration for women of childbearing age and the safety of the much larger general population [53]. Studies have shown improved folate status and decreases in NTD prevalence in the United States ranging from 19% to 32% [50].

Dietary indices

The prominence of dietary indices, utilized in a third of publications, was not surprising given that the evolution of nutrition research has increasingly focused on diet and dietary patterns in totality [54]. These tools synthesize multiple nutrient values and/or food groups into single numerical scores that reflect alignment with specific dietary recommendations or patterns [54]. By considering the overall diet, researchers can study how combinations of foods and eating behaviors contribute to health or how dietary intakes meet recommendations.

The USDA’s HEI was the most frequently used dietary index in this scoping review, reported in nearly 20% of the 2203 included studies, or about two-thirds of the 677 included studies that used a dietary index. The HEI is a measure of diet quality used to assess how well a set of foods aligns with key recommendations in the DGA [15], with nutrients comprising 5 of its 13 components, depending on the version. The remaining components come from the USDA’s Food Patterns Equivalents Database, which is a further characterization of foods in the FNNDS.

Nutrient intake data provided by WWEIA, NHANES continue to play a pivotal role not only in nutrition research but also in the development and maintenance of key federal policies and programs. An important strength of this data is the ability to assess population-level intakes as a means of monitoring public health and evaluating federal policies and health objectives over time. Ensuring that the underlying food composition data supporting WWEIA, NHANES data are accurate will continue to be relevant to USDA’s mission when supporting this data collection.

Strengths and limitations

A key strength of this study was the utilization of a systematic and rigorous search strategy employed across multiple databases. The comprehensive search was designed to capture all peer-reviewed studies that reported ≥1 nutrient from WWEIA, NHANES data during the study period. In addition, publications underwent a standardized screening, assessment, and extraction process guided by a data extraction manual to reduce bias and increase reproducibility. All stages of the process involved independent 2-party review with third-party conflict resolution to minimize reviewer bias. Finally, the use of dietary indices to identify sets of nutrients during the data extraction process enhanced the accuracy of the collected data.

Despite these strengths, this scoping review had inherent limitations. This study was limited to peer-reviewed, scientific literature published between 1 January, 2013 and 18 October, 2023. More recent studies, studies inadvertently missed due to limitations in search query sensitivity or database selection, and studies appearing in the gray literature were not captured. Finally, this review only assessed the reporting of nutrients and not how they were used in the research. Assessing how the identified nutrients are used in research, both overall and within subpopulations such as within age and life stage groups, is a potential area for further research.

Conclusions

This study describes the reporting of nutrients from WWEIA, NHANES data using a rigorous scoping review methodology. Not surprisingly, nutrients that have established roles in chronic disease risk and public health guidelines and policies, such as energy, protein, sodium, and total SFAs and PUFAs, appear more frequently in the literature. The diverse and widespread use of these continuously collected, nationally representative, publicly available data demonstrate their ongoing importance in nutrition research.

Abbreviations:

AMPM

Automated Multiple-Pass Method

DGA

Dietary Guidelines for Americans

DPA

docosapentaenoic acid

FNDDS

Food and Nutrient Database for Dietary Studies

HEI

Healthy Eating Index

NTD

neural tube defect

WWEIA

What We Eat in America

The term “nutrients” refers to nutrients and food components reported in FNDDS except added vitamin B12 and added vitamin E.

Appendix A. Supplementary data

Supplementary data to this article can be found online at https://doi.org/10.1016/j.tjnut.2025.09.018.

Data availability

Data described in the manuscript is made publicly and freely available without restriction within the publication and supplemental tables.