National Food Intake Assessment: Technologies to Advance Traditional Methods.

National dietary surveillance produces dietary intake data used for various purposes including development and evaluation of national policies in food and nutrition. Since 2000, What We Eat in America, the dietary component of the National Health and Nutrition Examination Survey, has collected dietary data and reported on the dietary intake of the US population. Continual innovations are required to improve methods of data collection, quality, and relevance. This review article evaluates the strengths and limitations of current and newer methods in national dietary data collection, underscoring the use of technology and emerging technology applications. We offer four objectives for national dietary surveillance that serve as guiding principles in the evaluation. Moving forward, national dietary surveillance must take advantage of new technologies for their potential in enhanced efficiency and objectivity in data operations while continuing to collect accurate dietary information that is standardized, validated, and publicly transparent.

Development and Validation of a Physical Food Security Tool for Older Adults.

BACKGROUND: Current measures of food insecurity focus on economic access to food, but not on the physical aspect of food insecurity that captures the inability to access food or prepare meals. This is particularly relevant among the older adult population who are at a high risk of functional impairments. OBJECTIVES: To develop a short-form physical food security (PFS) tool among older adults using statistical methods based on the Item Response Theory (Rasch) model. METHODS: Pooled data from adults aged ≥60 y of the NHANES (2013-2018) (n = 5892) were used. The PFS tool was derived from the physical limitation questions included in the physical functioning questionnaire of NHANES. Item severity parameters, fit and reliability statistics, and residual correlation between items were estimated using the Rasch model. The construct validity of the tool was assessed by examining associations with the Healthy Eating Index (HEI)-2015 scores, self-reported health, self-reported diet quality, and economic food insecurity, using weighted multivariable linear regression analysis, controlling for potential confounders. RESULTS: A 6-item scale was developed, which had adequate fit statistics and high reliability (0.62). It was categorized based on raw score severity into high, marginal, low, and very low PFS. Very low PFS was associated with respondent's self-reported poor health (OR = 23.8; 95% CI: 15.3, 36.9; P < 0.0001), self-reported poor diet (OR = 3.9; 95% CI: 2.8, 5.5; P < 0.0001), low and very low economic food security (OR = 6.08; 95% CI: 4.23, 8.76; P < 0.0001), and with lower mean HEI-2015 index score, in comparison to older adults with high PFS (54.5 compared with 57.5, P = 0.022). CONCLUSIONS: The proposed 6-item PFS scale captures a new dimension of food insecurity that can inform on how older adults experience food insecurity. The tool will require further testing and evaluation in larger and different contexts to demonstrate its external validity.

Measuring Food Insecurity in Older Adults Using Both Physical and Economic Food Access, NHANES 2013-18.

BACKGROUND: Economic food insecurity tools are used to detect need for assistance in the general population. However, in older adults, food insecurity can also be due to factors other than economic, such as physical inability to shop or cook. OBJECTIVES: We determined: 1) the proportion of older adults in the United States who experience physical and/or economic food insecurity; 2) differences in characteristics, diet quality, chronic conditions, and depression by economic and/or physical food insecurity; and 3) the relation of physical and economic food insecurity with diet quality and with depression. METHODS: Data from adults aged ≥60 y of the NHANES (2013-2018) were used. Groups were created based on economic food security [measured using the USDA's Household Food Security Survey Module (HFSSM)] and physical food security (measured using questions evaluating ability to shop and cook). Depression, Healthy Eating Index (HEI-2015) score, and socioeconomic characteristics were compared by food security group. Rao-Scott χ2 tests were used to test for significant differences between categorical variables, and t tests for continuous variables. Associations between food security status, HEI-2015, and depression score were examined using linear regression analysis. RESULTS: One-quarter (25.0%) of older adults had physical difficulty accessing food but were not living in economically food insecure households. Those who lived in economically food insecure households and also had physical difficulties accessing food had the lowest mean HEI-2015 score (51.7) and highest mean depression score (6.9); both were significantly lower than the mean scores of those who lived in food secure households (HEI-2015 = 57.3; depression = 2.1; P < 0.01). CONCLUSIONS: Considering physical ability to shop for and prepare food when measuring food insecurity in older adults can help identify those who might need dietary and mental health support the most, and those who need food assistance but would otherwise be missed if only measuring economic access.

Awareness and use of nutrition information predict measured and self-rated diet quality of older adults in the USA.

OBJECTIVES: To examine: (1) diet quality of older adults, using the Healthy Eating Index 2010 (HEI-2010) and self-rated diet quality, (2) characteristics associated with reported awareness and use of nutrition information and (3) factors associated with HEI score and self-rated diet quality. DESIGN: Cross-sectional study. Based on Day 1 and/or Day 2 dietary recalls, the Per-Person method was used to estimate HEI-2010 component and total scores. T-tests and ANOVA were used to compare means. Logistic and linear regressions were used to test for associations with diet quality, controlling for potential confounders. SETTING: National Health and Nutrition Examination Survey, 2009-2014. PARTICIPANTS: Three thousand and fifty-six adults, aged 60 years and older, who completed at least one 24-h recall and answered questions on awareness and use of nutrition information. RESULTS: Mean HEI score for men was significantly lower than for women (56·4 ± 0·6 v. 60·2 ± 0·6, P < 0·0001). Compared with men, more women were aware of (44·8 % v. 33·7 %, P < 0·05) and used (13·7 % v. 5·9 %, P < 0·05) nutrition information. In multivariable analyses, awareness and use of nutrition information were significant predictors of both HEI and self-rated diet quality for both women and men. Groups with lower nutrition awareness included men, non-Whites, participants in nutrition assistance programmes and those with lower education and socio-economic status. CONCLUSIONS: Nutrition awareness and use of nutrition information are associated with diet quality in adults 60 years and older. Gaps in awareness of dietary guidelines in certain segments of the older adult population suggest that targeted education may improve diet quality for these groups.

Comparison of 4 Methods to Assess the Prevalence of Use and Estimates of Nutrient Intakes from Dietary Supplements among US Adults.

BACKGROUND: Accurate and reliable methods to assess prevalence of use of and nutrient intakes from dietary supplements (DSs) are critical for research, clinical practice, and public health monitoring. NHANES has been the primary source of DS usage patterns using an in-home inventory with a frequency-based DS and Prescription Medicine Questionnaire (DSMQ), but little is known regarding DS information obtained from 24-h dietary recalls (24HRs). METHODS: The objectives of this analysis were to compare results from 4 different methods for measuring DS use constructed from two data collection instruments (i.e., DSMQ and 24HR) and to determine the most comprehensive method for measuring the prevalence of use and estimating nutrient intakes from DS for selected nutrients. NHANES 2011-2014 data from US adults (aged ≥19 y; n = 11,451) were used to examine the 4 combinations of methods constructed for measuring the prevalence of use of and amount of selected nutrients from DSs (i.e., riboflavin, vitamin D, folate, magnesium, calcium): 1) DSMQ, 2) 24HR day 1, 3) two 24HRs (i.e., mean), and 4) DSMQ or at least one 24HR. RESULTS: Half of US adults reported DS use on the DSMQ (52%) and on two 24HRs (mean of 49%), as compared with a lower prevalence of DS use when using a single 24HR (43%) and a higher (57%) prevalence when combining the DSMQ with at least one 24HR. Mean nutrient intake estimates were highest using 24HR day 1. Mean supplemental calcium from the DSMQ or at least one 24HR was 372 mg/d, but 464 mg/d on the 24HR only. For vitamin D, the estimated intakes per consumption day were higher on the DSMQ (46 µg) and the DSMQ or at least one 24HR (44 µg) than those on the 24HR day 1 (32 µg) or the mean 24HR (31 µg). Fewer products were also classed as a default or reasonable match on the DSMQ than on the 24HR. CONCLUSIONS: A higher prevalence of use of DSs is obtained using frequency-based methods, whereas higher amounts of nutrients are reported from a 24HR. The home inventory results in greater accuracy for products reported. Collectively, these findings suggest that combining the DSMQ with at least one 24HR (i.e., DSMQ or at least one 24HR) is the most comprehensive method for assessing the prevalence of and estimating usual intake from DSs in US adults.This trial was registered at clinicaltrials.gov as NCT03400436.

Top Food Category Contributors to Sodium and Potassium Intake - United States, 2015-2016.

Most U.S. adults consume too much sodium and not enough potassium (1,2). For apparently healthy U.S. adults aged ≥19 years, guidelines recommend reducing sodium intake that exceeds 2,300 mg/day and consuming at least 3,400 mg/day of potassium for males and at least 2,600 mg/day for females* (1). Reducing population-level sodium intake can reduce blood pressure and prevent cardiovascular diseases, the leading causes of death in the United States (1,3). Adequate potassium intake might offset the hypertensive effects of excessive sodium intake (1). Data from the 2015-2016 What We Eat in America (WWEIA) dietary interview component of the National Health and Nutrition Examination Survey (NHANES)† were analyzed to identify top food categories contributing to sodium and potassium intake for U.S. residents aged ≥1 year. During 2015-2016, 40% of sodium consumed came from the top 10 food categories, which included prepared foods with sodium added (e.g., deli meat sandwiches and pizza). Approximately 43% of potassium consumed was from 10 food categories, which included foods naturally low in sodium (e.g., unflavored milk, fruit, vegetables) and prepared foods. These results can inform efforts to encourage consumption of foods naturally low in sodium, which might have the dual benefit of reducing sodium intake and increasing potassium intake, contributing to cardiovascular disease prevention.

Nutritional Intake and Bone Health Among Adults With Probable Undiagnosed, Untreated Celiac Disease: What We Eat in America and NHANES 2009-2014.

Objective: The aim was to evaluate differences in nutritional intake of calcium, vitamin D, and phosphorus; serologic indices of these nutrients; and bone health among adults with and without probable, undiagnosed celiac disease (CD).Method: Cross-sectional data from What We Eat in America and the National Health and Nutrition Examination Survey 2009-2014 including self-reported dietary and supplement intake from one day of 24-hour recalls, serologic indicators, and dual x-ray absorptiometry scans were analyzed in adults with probable undiagnosed CD, who tested positive on the immunoglobulin A endomysial antibody assay (n = 48) and controls (n = 13,634). Statistical analysis included multiple linear regression modeling controlled for age, sex, race/ethnicity, energy intake, and poverty income ratio.Results: The prevalence of probable undiagnosed CD was 1 in 285. Probable CD status was associated with a 251.6 mg (95% confidence interval [CI], 72.3-432.9) higher daily total calcium intake. The total dietary and supplement intake of those with probable CD was significantly higher in calcium density (103.4 mg/1,000 kcal; 95% CI, 25.6-181.1) and phosphorus density (46.7 mg/1,000 kcal; 95% CI, 3.1-90.3). Probable CD status was associated with higher dairy consumption by 0.7 cups per day (95% CI, 0.2-1.2) and higher serum phosphorus concentrations (4.0 mg/dL vs 3.8 mg/dL, p = 0.011). No differences in serum calcium, vitamin D, or alkaline phosphatase levels were observed between groups. Probable CD status was also associated with a -0.1 g/cm2 (95% CI, -0.2 to -0.0) lower femur bone mineral density (BMD) and a -0.1 g/cm2 (95% CI, -0.1 to -0.0) lower femoral neck BMD. No differences in total spine BMD were observed.Conclusions: Adults with probable undiagnosed CD had lower bone density than adults without CD, despite also reporting higher total calcium intake and nutritional density of both calcium and phosphorus.

Self-Reported Measures of Discretionary Salt Use Accurately Estimated Sodium Intake Overall but not in Certain Subgroups of US Adults from 3 Geographic Regions in the Salt Sources Study.

BACKGROUND: Excess sodium intake can increase blood pressure, and high blood pressure is a major risk factor for cardiovascular disease. Accurate population sodium intake estimates are essential for monitoring progress toward reduction, but data are limited on the amount of sodium consumed from discretionary salt. OBJECTIVES: The aim of this study was to compare measured sodium intake from salt added at the table with that estimated according to the Healthy People 2020 (HP 2020) methodology. METHODS: Data were analyzed from the 2014 Salt Sources Study, a cross-sectional convenience sample of 450 white, black, Asian, and Hispanic adults living in Alabama, Minnesota, and California. Sodium intake from foods and beverages was assessed for each participant through the use of 24-h dietary recalls. Estimated sodium intake from salt used at the table was assessed from self-reported frequency and estimated amounts from a previous study (HP 2020 methodology). Measured intake was assessed through the use of duplicate salt samples collected on recall days. RESULTS: Among all study participants, estimated and measured mean sodium intakes from salt added at the table were similar, with a nonsignificant difference of 8.9 mg/d (95% CI: -36.6, 54.4 mg/d). Among participants who were non-Hispanic Asian, Hispanic, had a bachelor's degree or higher education, lived in California or Minnesota, did not report hypertension, or had normal BMI, estimated mean sodium intake was 77-153 mg/d greater than measured intake (P < 0.05). The estimated mean sodium intake was 186-300 mg/d lower than measured intake among participants who were non-Hispanic black, had a high school degree or less, or reported hypertension (P < 0.05). CONCLUSIONS: The HP 2020 methodology for estimating sodium consumed from salt added at the table may be appropriate for the general US adult population; however, it underestimates intake in certain population subgroups, particularly non-Hispanic black, those with a high school degree or less, or those with self-reported hypertension. This study was registered at clinicaltrials.gov as NCT02474693.

Findings from What We Eat in America, National Health and Nutrition Examination Survey 2011-2014 support salad consumption as an effective strategy for improving adherence to dietary recommendations.

OBJECTIVE: To verify the previously untested assumption that eating more salad enhances vegetable intake and determine if salad consumption is in fact associated with higher vegetable intake and greater adherence to the Dietary Guidelines for Americans (DGA) recommendations. DESIGN: Individuals were classified as salad reporters or non-reporters based upon whether they consumed a salad composed primarily of raw vegetables on the intake day. Regression analyses were applied to calculate adjusted estimates of food group intakes and assess the likelihood of meeting Healthy US-Style Food Pattern recommendations by salad reporting status. SETTING: Cross-sectional analysis of data collected in 2011-2014 in What We Eat in America, the dietary intake component of the National Health and Nutrition Examination Survey.ParticipantsUS adults (n 9678) aged ≥20 years (excluding pregnant and lactating women). RESULTS: On the intake day, 23 % of adults ate salad. The proportion of individuals reporting salad varied by sex, age, race, income, education and smoking status (P<0·001). Compared with non-reporters, salad reporters consumed significantly larger quantities of vegetables (total, dark green, red/orange and other), which translated into a two- to threefold greater likelihood of meeting recommendations for these food groups. More modest associations were observed between salad consumption and differences in intake and likelihood of meeting recommendations for protein foods (total and seafood), oils and refined grains. CONCLUSIONS: Study results confirm the DGA message that incorporating more salads in the diet is one effective strategy (among others, such as eating more cooked vegetables) to augment vegetable consumption and adherence to dietary recommendations concerning vegetables.

Mineral Intake Ratios Are a Weak but Significant Factor in Blood Pressure Variability in US Adults.

Background: Hypertension contributes substantially to chronic disease and mortality. Mineral intakes can modify blood pressure. Objective: Individual minerals and their intake ratios in US adults and their association with blood pressure were examined. Methods: Regression models were used to examine the associations of sodium, potassium, and calcium intakes and their ratios from food and supplements with blood pressure in 8777 US adults without impaired renal function from the 2011-2014 NHANES. We evaluated men (n = 4395) and women (n = 4382) separately. Models for predicting blood pressure were developed using age, blood pressure medication, race, body mass index (BMI), and smoking as explanatory variables. Results: Few adults met the recommended intake ratios for sodium:potassium (1.2% and 1.5%), sodium:calcium (12.8% and 17.67%), and sodium:magnesium (13.7% and 7.3%) for men and women, respectively. Approximately half of adults (55.2% of men and 54.8% of women) met calcium:magnesium intake ratio recommendations. In our regression models, the factors that explained the largest amount of variability in blood pressure were age, blood pressure medication, race/ethnicity, BMI, and smoking status. Together, these factors explained 31% and 15% of the variability in systolic blood pressure in women and men, respectively. The sodium:potassium (men and women), sodium:magnesium (women), and sodium:calcium (men) intake ratios were positively associated with systolic blood pressure, whereas calcium intake was inversely associated with systolic blood pressure in men only. When mineral intake ratios were added individually to our regression models, they improved the percentage of variability in blood pressure explained by the model by 0.13-0.21%. Conclusions: Strategies to lower blood pressure are needed. Lower sodium:potassium intake ratios provide a small benefit for protection against hypertension in US adults.

Evaluation of the 24-Hour Recall as a Reference Instrument for Calibrating Other Self-Report Instruments in Nutritional Cohort Studies: Evidence From the Validation Studies Pooling Project.

Calibrating dietary self-report instruments is recommended as a way to adjust for measurement error when estimating diet-disease associations. Because biomarkers available for calibration are limited, most investigators use self-reports (e.g., 24-hour recalls (24HRs)) as the reference instrument. We evaluated the performance of 24HRs as reference instruments for calibrating food frequency questionnaires (FFQs), using data from the Validation Studies Pooling Project, comprising 5 large validation studies using recovery biomarkers. Using 24HRs as reference instruments, we estimated attenuation factors, correlations with truth, and calibration equations for FFQ-reported intakes of energy and for protein, potassium, and sodium and their densities, and we compared them with values derived using biomarkers. Based on 24HRs, FFQ attenuation factors were substantially overestimated for energy and sodium intakes, less for protein and potassium, and minimally for nutrient densities. FFQ correlations with truth, based on 24HRs, were substantially overestimated for all dietary components. Calibration equations did not capture dependencies on body mass index. We also compared predicted bias in estimated relative risks adjusted using 24HRs as reference instruments with bias when making no adjustment. In disease models with energy and 1 or more nutrient intakes, predicted bias in estimated nutrient relative risks was reduced on average, but bias in the energy risk coefficient was unchanged.

Sodium Intake Among Persons Aged ≥2 Years - United States, 2013-2014.

High sodium consumption can increase hypertension, a major risk factor for cardiovascular diseases (1). Reducing sodium intake can lower blood pressure, and sodium reduction in the U.S. population of 40% over 10 years might save at least 280,000 lives (2). Average sodium intake in the United States remains in excess of Healthy People 2020 objectives,* and monitoring sources of sodium in the U.S. population can help focus sodium reduction measures (3,4). Data from 2013-2014 What We Eat in America (WWEIA), the dietary intake portion of the National Health and Nutrition Examination Survey (NHANES),† were analyzed to determine the ranked percentage sodium contribution of selected food categories and sources of sodium intake from all reported foods and beverages, both overall and by demographic subgroups. These latest data include updated food codes and separate estimates for intake among non-Hispanic Asians.§ In 2013-2014, 70% of dietary sodium consumed by persons in the United States came from 25 food categories; breads were the top contributor, accounting for 6% of sodium consumed. A majority of sodium consumed was from food obtained at stores; however, sodium density (mg/1,000 kcal) was highest in food obtained at restaurants. A variety of commonly consumed foods contributes to U.S. sodium intake, emphasizing the importance of sodium reduction across the food supply (4).

Trends and determinants of discretionary salt use: National Health and Nutrition Examination Survey 2003-2012.

OBJECTIVE: To examine temporal trends and determinants of discretionary salt use in the USA. DESIGN: Multiple logistic regression was used to assess temporal trends in discretionary salt use at the table and during home cooking/preparation, adjusting for demographic characteristics, using data from the National Health and Nutrition Examination Survey 2003-2012. Prevalence and determinants of discretionary salt use in 2009-2012 were also examined. SETTING: Participants answered salt use questions after completing a 24 h dietary recall in a mobile examination centre. SUBJECTS: Nationally representative sample of non-institutionalized US children and adults, aged ≥2 years. RESULTS: From 2003 to 2012, the proportion of the population who reported using salt 'very often' declined; from 18 % to 12 % for use at the table (P<0·01) and from 42 % to 37 % during home cooking (P<0·02). While one-third of the population reported never adding salt at the table, most used it during home cooking/preparation (93 %). Use of discretionary salt was least commonly reported among young children and older adults and demographic and health subgroups at risk of CVD. CONCLUSIONS: While most people reported using salt during home cooking/preparation, a minority reported use at the table. Reported 'very often' discretionary salt use has declined. That discretionary salt use is less common among those at risk of CVD suggests awareness of messages to limit Na intake.

Pooled results from 5 validation studies of dietary self-report instruments using recovery biomarkers for potassium and sodium intake.

We pooled data from 5 large validation studies (1999-2009) of dietary self-report instruments that used recovery biomarkers as referents, to assess food frequency questionnaires (FFQs) and 24-hour recalls (24HRs). Here we report on total potassium and sodium intakes, their densities, and their ratio. Results were similar by sex but were heterogeneous across studies. For potassium, potassium density, sodium, sodium density, and sodium:potassium ratio, average correlation coefficients for the correlation of reported intake with true intake on the FFQs were 0.37, 0.47, 0.16, 0.32, and 0.49, respectively. For the same nutrients measured with a single 24HR, they were 0.47, 0.46, 0.32, 0.31, and 0.46, respectively, rising to 0.56, 0.53, 0.41, 0.38, and 0.60 for the average of three 24HRs. Average underreporting was 5%-6% with an FFQ and 0%-4% with a single 24HR for potassium but was 28%-39% and 4%-13%, respectively, for sodium. Higher body mass index was related to underreporting of sodium. Calibration equations for true intake that included personal characteristics provided improved prediction, except for sodium density. In summary, self-reports capture potassium intake quite well but sodium intake less well. Using densities improves the measurement of potassium and sodium on an FFQ. Sodium:potassium ratio is measured much better than sodium itself on both FFQs and 24HRs.

Application of a New Statistical Model for Measurement Error to the Evaluation of Dietary Self-report Instruments.

Most statistical methods that adjust analyses for dietary measurement error treat an individual's usual intake as a fixed quantity. However, usual intake, if defined as average intake over a few months, varies over time. We describe a model that accounts for such variation and for the proximity of biomarker measurements to self-reports within the framework of a meta-analysis, and apply it to the analysis of data on energy, protein, potassium, and sodium from a set of five large validation studies of dietary self-report instruments using recovery biomarkers as reference instruments. We show that this time-varying usual intake model fits the data better than the fixed usual intake assumption. Using this model, we estimated attenuation factors and correlations with true longer-term usual intake for single and multiple 24-hour dietary recalls (24HRs) and food frequency questionnaires (FFQs) and compared them with those obtained under the "fixed" method. Compared with the fixed method, the estimates using the time-varying model showed slightly larger values of the attenuation factor and correlation coefficient for FFQs and smaller values for 24HRs. In some cases, the difference between the fixed method estimate and the new estimate for multiple 24HRs was substantial. With the new method, while four 24HRs had higher estimated correlations with truth than a single FFQ for absolute intakes of protein, potassium, and sodium, for densities the correlations were approximately equal. Accounting for the time element in dietary validation is potentially important, and points toward the need for longer-term validation studies.

A New Database Facilitates Characterization of Flavonoid Intake, Sources, and Positive Associations with Diet Quality among US Adults.

BACKGROUND: Epidemiologic studies demonstrate inverse associations between flavonoid intake and chronic disease risk. However, lack of comprehensive databases of the flavonoid content of foods has hindered efforts to fully characterize population intakes and determine associations with diet quality. OBJECTIVES: Using a newly released database of flavonoid values, this study sought to describe intake and sources of total flavonoids and 6 flavonoid classes and identify associations between flavonoid intake and the Healthy Eating Index (HEI) 2010. METHODS: One day of 24-h dietary recall data from adults aged ≥ 20 y (n = 5420) collected in What We Eat in America (WWEIA), NHANES 2007-2008, were analyzed. Flavonoid intakes were calculated using the USDA Flavonoid Values for Survey Foods and Beverages 2007-2008. Regression analyses were conducted to provide adjusted estimates of flavonoid intake, and linear trends in total and component HEI scores by flavonoid intake were assessed using orthogonal polynomial contrasts. All analyses were weighted to be nationally representative. RESULTS: Mean intake of flavonoids was 251 mg/d, with flavan-3-ols accounting for 81% of intake. Non-Hispanic whites had significantly higher (P < 0.001) intakes of total flavonoids (275 mg/d) than non-Hispanic blacks (176 mg/d) and Hispanics (139 mg/d). Tea was the primary source (80%) of flavonoid intake. Regardless of whether the flavonoid contribution of tea was included, total HEI score and component scores for total fruit, whole fruit, total vegetables, greens and beans, seafood and plant proteins, refined grains, and empty calories increased (P < 0.001) across flavonoid intake quartiles. CONCLUSIONS: A new database that permits comprehensive estimation of flavonoid intakes in WWEIA, NHANES 2007-2008; identification of their major food/beverage sources; and determination of associations with dietary quality will lead to advances in research on relations between flavonoid intake and health. Findings suggest that diet quality, as measured by HEI, is positively associated with flavonoid intake.

Estimating Sodium and Potassium Intakes and Their Ratio in the American Diet: Data from the 2011-2012 NHANES.

BACKGROUND: The dietary sodium-to-potassium ratio (Na:K) is shown to be more strongly associated with an increased risk of cardiovascular disease (CVD) and CVD-related mortality than either sodium or potassium intake alone. OBJECTIVE: The aim was to estimate the Na:K in the diet of US adults. METHODS: Among US adults from the 2011-2012 NHANES (≥20 y; 2393 men and 2337 women), the National Cancer Institute method was used to estimate sodium and potassium intakes, Na:K, and the percentage of individuals with Na:K <1.0 utilizing the complex, stratified, multistage probability cluster sampling design. RESULTS: Overall, women had a significantly lower Na:K than men (mean ± SE: 1.32 ± 0.02 compared with 1.45 ± 0.02). Non-Hispanic whites had a significantly lower Na:K than non-Hispanic blacks and non-Hispanic Asians (1.34 ± 0.02 compared with 1.54 ± 0.03 and 1.49 ± 0.04, respectively). Only 12.2% ± 1.5% of US adults had a Na:K < 1.0. The Na:K decreased linearly as age increased. Most adults (90% ± 0.8%) had sodium intakes >2300 mg/d, whereas <3% had potassium intakes >4700 mg/d. Grains and vegetables were among the highest contributors to sodium intakes for adults with Na:K < 1.0, compared with protein foods and grains for those with Na:K ≥ 1.0. Vegetables and milk and dairy products constituted the primary dietary sources of potassium for individuals with Na:K < 1.0, whereas mixed dishes and protein foods contributed the most potassium for individuals with ratios ≥1.0. Individuals with a Na:K < 1.0 were less likely to consume mixed dishes and condiments and were more likely to consume vegetables, milk and dairy products, and fruit than those with a Na:K ≥ 1.0. CONCLUSION: Only about one-tenth of US adults have a Na:K consistent with the WHO guidelines for reduced risk of mortality. Continued efforts to reduce sodium intake in tandem with novel strategies to increase potassium intake are warranted.

Pooled results from 5 validation studies of dietary self-report instruments using recovery biomarkers for energy and protein intake.

We pooled data from 5 large validation studies of dietary self-report instruments that used recovery biomarkers as references to clarify the measurement properties of food frequency questionnaires (FFQs) and 24-hour recalls. The studies were conducted in widely differing US adult populations from 1999 to 2009. We report on total energy, protein, and protein density intakes. Results were similar across sexes, but there was heterogeneity across studies. Using a FFQ, the average correlation coefficients for reported versus true intakes for energy, protein, and protein density were 0.21, 0.29, and 0.41, respectively. Using a single 24-hour recall, the coefficients were 0.26, 0.40, and 0.36, respectively, for the same nutrients and rose to 0.31, 0.49, and 0.46 when three 24-hour recalls were averaged. The average rate of under-reporting of energy intake was 28% with a FFQ and 15% with a single 24-hour recall, but the percentages were lower for protein. Personal characteristics related to under-reporting were body mass index, educational level, and age. Calibration equations for true intake that included personal characteristics provided improved prediction. This project establishes that FFQs have stronger correlations with truth for protein density than for absolute protein intake, that the use of multiple 24-hour recalls substantially increases the correlations when compared with a single 24-hour recall, and that body mass index strongly predicts under-reporting of energy and protein intakes.

Vital signs: sodium intake among U.S. school-aged children - 2009-2010.

BACKGROUND: A national health objective is to reduce average U.S. sodium intake to 2,300 mg daily to help prevent high blood pressure, a major cause of heart disease and stroke. Identifying common contributors to sodium intake among children can help reduction efforts. METHODS: Average sodium intake, sodium consumed per calorie, and proportions of sodium from food categories, place obtained, and eating occasion were estimated among 2,266 school-aged (6­18 years) participants in What We Eat in America, the dietary intake component of the National Health and Nutrition Examination Survey, 2009­2010. RESULTS: U.S. school-aged children consumed an estimated 3,279 mg of sodium daily with the highest total intake (3,672 mg/d) and intake per 1,000 kcal (1,681 mg) among high school­aged children. Forty-three percent of sodium came from 10 food categories: pizza, bread and rolls, cold cuts/cured meats, savory snacks, sandwiches, cheese, chicken patties/nuggets/tenders, pasta mixed dishes, Mexican mixed dishes, and soups. Sixty-five percent of sodium intake came from store foods, 13% from fast food/pizza restaurants, 5% from other restaurants, and 9% from school cafeteria foods. Among children aged 14­18 years, 16% of total sodium intake came from fast food/pizza restaurants versus 11% among those aged 6­10 years or 11­13 years (p<0.05). Among children who consumed a school meal on the day assessed, 26% of sodium intake came from school cafeteria foods. Thirty-nine percent of sodium was consumed at dinner, followed by lunch (29%), snacks (16%), and breakfast (15%). IMPLICATIONS FOR PUBLIC HEALTH PRACTICE: Sodium intake among school-aged children is much higher than recommended. Multiple food categories, venues, meals, and snacks contribute to sodium intake among school-aged children supporting the importance of populationwide strategies to reduce sodium intake. New national nutrition standards are projected to reduce the sodium content of school meals by approximately 25%­50% by 2022. Based on this analysis, if there is no replacement from other sources, sodium intake among U.S. school-aged children will be reduced by an average of about 75­150 mg per day and about 220­440 mg on days children consume school meals.