Biochemical Validation of a Self-Administered Carotenoid Intake Screener to Assess Carotenoid Intake in Nonobese Adults.

Background: Epidemiological studies have demonstrated an association between carotenoid intake and health. However, an accurate measurement of carotenoid intake is challenging. FFQ is the most commonly used dietary assessment method and is typically composed of 100-200 items. However, the greater participant burden that accompanies a more detailed FFQ provides only a marginal gain in accuracy. Therefore, a brief validated carotenoid intake screener is needed. Objectives: To conduct secondary analysis evaluating the validity of a newly developed 44-item carotenoid intake screener from The Juice Study: Sensitivity of Skin Carotenoid Status to Detect Change in Intake (NCT03202043) against corresponding plasma carotenoid concentrations (primary) and skin carotenoids (secondary) in nonobese Midwestern American adults. Methods: Healthy adults (n = 83; 25 men and 58 women) aged 18-65 y (mean age, 32 ± 12 y) with a BMI (in kg/m2) of 18.5-29.9 (mean BMI, 25 ± 3) were recruited between 25 April 2018 and 28 March 2019. Participants completed the carotenoid intake screener weekly during the 8-wk parent study. Plasma carotenoid concentrations were assessed at weeks 0, 4, and 8 using HPLC. Skin carotenoids were assessed weekly using pressure-mediated reflection spectroscopy (RS). Correlation matrices from mixed models were used to determine the correlation between carotenoid intake and plasma and skin carotenoids over time. Results: The total carotenoid intake, as determined by the carotenoid intake screener, correlated with both the plasma total carotenoid concentration (r = 0.52; P < 0.0001) and the RS-assessed skin carotenoid concentration (r = 0.43; P < 0.0001). Correlations between reported intake and plasma concentrations of α-carotene (r = 0.40; P = 0.0002), cryptoxanthin (r = 0.28; P = 0.0113), and lycopene (r = 0.33; P = 0.0022) were also observed. Conclusions: The results of this study demonstrate an acceptable relative validity of the carotenoid intake screener to assess total carotenoid intake in adults classified as those having a healthy body or those with overweight.

Sensitivity of Pressure-Mediated Reflection Spectroscopy to Detect Changes in Skin Carotenoids in Adults Without Obesity in Response to Increased Carotenoid Intake: A Randomized Controlled Trial.

BACKGROUND: The sensitivity of commercially available devices to detect changes in skin carotenoids is not known. OBJECTIVES: We aimed to determine the sensitivity of pressure-mediated reflection spectroscopy (RS) to detect changes in skin carotenoids in response to increasing carotenoid intake. METHODS: Nonobese adults were randomly assigned to a control (water; n = 20; females = 15 (75%); mean age: 31 ± 3 (SE) y; mean BMI: 26 ± 1 kg/m2) or one of 3 carotenoid intake levels: 1) LOW - 13.1 mg; n = 22; females = 18(82%); age: 33 ± 3 y; BMI: 25 ± 1 kg/m2; 2) MED - 23.9 mg; n = 22; females = 17 (77%); age: 30 ± 2 y; BMI: 26 ± 1 kg/m2); or 3) HIGH - 31.0 mg; n = 19; females = 9 (47%); age: 33 ± 3 y; BMI: 24 ± 1 kg/m2. A commercial vegetable juice was provided daily to ensure that the additional carotenoid intake was achieved. Skin carotenoids (RS intensity [RSI]) were measured weekly. Plasma carotenoid concentrations were assessed at wk 0, 4, and 8. Mixed models were used to test the effect of treatment, time, and their interaction. Correlation matrices from mixed models were used to determine the correlation between plasma and skin carotenoids. RESULTS: A correlation was observed between skin and plasma carotenoids (r = 0.65; P < 0.001). Skin carotenoids were greater than baseline starting at week 1 in the HIGH (290 ± 20 vs. 321 ± 24 RSI; P ≤ 0.01), week 2 in the MED (274 ± 18 vs. 290 ± 23 RSI; P ≤ 0.03), and week 3 in the LOW (261 ± 18 vs. 288 ± 15 RSI; P ≤ 0.03). Compared with control, differences in skin carotenoids were observed starting at week 2 in the HIGH ([268 ± 16 vs. 338 ± 26 RSI; P ≤ 0.01] except for week 3 [287 ± 20 vs. 335 ± 26 RSI; P = 0.08]) and week 6 in the MED (303 ± 26 vs. 363 ± 27 RSI; P ≤ 0.03). No differences were observed between the control and LOW. CONCLUSIONS: These findings demonstrate that RS can detect changes in skin carotenoids in adults without obesity when daily carotenoid intake is increased by 13.1 mg for a minimum of 3 wk. However, a minimum difference in intake of 23.9 mg of carotenoids is needed to detect group differences. This trial was registered at ClinicalTrials.gov as NCT03202043.

Incorporating the Dietary Guidelines for Americans Vegetable Recommendations into the Diet Alters Dietary Intake Patterns of Other Foods and Improves Diet Quality in Adults with Overweight and Obesity.

BACKGROUND: Understanding how vegetables are incorporated into the diet, especially in the types and amounts recommended by the Dietary Guidelines for Americans, and how this alters dietary intake patterns is vital for developing targeted behavior change interventions. OBJECTIVE: To determine how a provision of vegetables was incorporated into the diet of adults with overweight and obesity; whether or not the provided vegetables displaced other foods; and what, if any, effect this had on diet quality and body weight and composition. DESIGN: This study investigated secondary outcomes from the Motivating Value of Vegetables Study, a community-based, randomized, parallel, nonblinded controlled trial. Participants were randomly assigned to a provided vegetable intervention or attention control group using a one to one allocation ratio. PARTICIPANTS/SETTING: Men and women with self-reported low vegetable consumption, aged 18 to 65 years, with a body mass index ≥25 were recruited from Grand Forks, ND, between October 2015 and September 2017. Only participants randomized to the provided vegetable intervention group (n = 51; attrition = 8%) were included in this secondary analysis. INTERVENTION: Dietary Guidelines for Americans recommended types and amounts of vegetables were provided weekly for 8 weeks. MAIN OUTCOME MEASURES: How the provided vegetables were incorporated into the diet was measured using daily self-report and 24-hour dietary recalls. Diet quality was assessed via the Healthy Eating Index 2015. Body weight and composition were measured before and after the intervention. STATISTICAL ANALYSES PERFORMED: Data were assessed using generalized linear mixed models where phase (pre, post) was the within-subject factor and subject was the random effect. RESULTS: Participants self-reported using 29% of the provided vegetables as substitutes for other foods. With the increase in vegetable consumption, there were decreases in total grains (mean difference ± standard deviation; -0.97 ± 3.23 oz-equivalents; P = 0.02), protein foods (-1.24 ± 3.86 oz-equivalents; P = 0.01), saturated fats (-6.44 ± 19.63 g; P = 0.02), and added sugars (-2.44 ± 6.78 tsp-equivalents; P = 0.02) consumed. Total Healthy Eating Index 2015 scores increased (+4.48 ± 9.63; P = 0.001) and dietary energy density decreased (-0.44 ± 0.52 kcal/g; P < 0.0001). There was no change in total energy intake or body weight and composition. CONCLUSIONS: Increasing vegetable consumption to meet Dietary Guidelines for Americans recommendations alters dietary intake patterns, improving diet quality and energy density. These findings highlight the importance of characterizing how individuals incorporate Dietary Guidelines for Americans recommendations into their diet.

Consumption of Dietary Guidelines for Americans Types and Amounts of Vegetables Increases Mean Subjective Happiness Scale Scores: A Randomized Controlled Trial.

BACKGROUND: The health benefits of diets rich in fruits and vegetables (FV) are well established. Recent observational and intervention research suggests that FV consumption may also exert a positive effect on psychological well-being. OBJECTIVE: This study aimed to assess changes in mean Subjective Happiness Scale (SHS) scores in response to consuming 2010-2015 Dietary Guidelines for Americans (DGA) recommended types and amounts of vegetables. It was hypothesized that increased vegetable consumption would increase mean SHS scores. DESIGN: This study investigated a secondary outcome of a randomized, parallel, nonblinded controlled trial with a 1:1 allocation ratio to a provided vegetable intervention or attention control group. PARTICIPANTS/SETTING: Men and women (n = 75) aged 18 to 65 years, body mass index ≥ 25, with low habitual vegetable consumption were recruited from Grand Forks, North Dakota, December 2016 to January 2018, for this community-based study. INTERVENTION: The vegetable intervention consisted of an 8-week feeding phase during which participants were provided with vegetables in DGA-recommended types and amounts. The attention control group was not provided vegetables but completed the same testing schedule as the vegetable intervention group. MAIN OUTCOME MEASURE: Mean SHS scores were assessed before and after the intervention. STATISTICAL ANALYSES: Mean SHS scores were analyzed using a 2-way factorial mixed linear model analysis of variance. RESULTS: A significant interaction between treatment and visit (P = .015) revealed greater mean SHS scores at week 8 than at baseline in the vegetable intervention group (+0.23 ± 0.11) (mean difference ± SE of the difference) but no change in the attention control group (-0.15 ± 0.11). CONCLUSIONS: Greater mean SHS scores were observed after increasing vegetable consumption to meet DGA recommendations, suggesting that adhering to DGA vegetable guidance may help promote psychological well-being.

Increasing Vegetable Intake Decreases Urinary Acidity and Bone Resorption Marker in Overweight and Obese Adults: An 8-Week Randomized Controlled Trial.

BACKGROUND: Controlled intervention trials are needed to confirm a positive association from epidemiological studies between vegetable consumption and bone health. OBJECTIVE: We investigated whether providing vegetables at the Dietary Guidelines for Americans (DGA) recommended amount affects excretion of acid and calcium in urine and bone turnover markers in serum in adults with low vegetable intake. METHODS: In total, 102 adults (19 males and 83 females, age 18-65 y, BMI ≥25 kg/m2) consuming ≤1 serving of vegetables (128 g raw leafy or 64 g cooked vegetables) per d were recruited in a 2-arm, parallel, randomized, controlled, and community-based 8-wk feeding intervention trial. The 2 arms included a vegetable intervention (VI) during which participants received extra vegetables (∼270 g/d) and an attention control (CON) group that conducted only the testing visits. Measurements included nutrient intake, plasma carotenoids, and bone-related markers in serum and urine. Differences between CON and VI at week 8 were tested using the ANCOVA with baseline values as a covariate. RESULTS: Compared with CON, carotenoid intake (mean ± SD) was higher (6.4 ± 3.4 compared with 2.0 ± 1.2 mg/d) (P < 0.01) and dietary potential renal acid load was lower (20 ± 13 compared with 3.4 ± 14 mEq/d) (P < 0.01) in VI. Compared with CON at week 8, urine titratable acid and Mg were 24 and 26% lower, respectively, while urine pH was 3% greater (P < 0.05) and serum C-terminal telopeptide of type I collagen (CTX) was 19% lower in VI. There were no group differences in serum concentrations of propeptide of type 1 procollagen and tartrate-resistant acid phosphatase or urinary excretion of deoxypyridinoline and CTX. CONCLUSIONS: Consumption of vegetables at the DGA-recommended amount by adults with low vegetable intake potentially benefits bone health. This trial was registered at clinicaltrials.gov as NCT02585102.

Energy intake and season interact to influence physiological stress load among midlife women.

Allostatic load (AL) is an index that measures physiologic stress associated with chronic disease risk. One factor that may influence overall physiologic stress load and AL is energy consumption, but whether this association differs across different seasons is unknown. We tested whether energy consumption interacted with the season to influence AL in 52 mid-life (40-60 years) women from the Life in All Seasons Study. Women completed an online 24-h recall every 10 days and had components of allostatic load measured seasonally. Women were from the greater Grand Forks, ND catchment area and were followed for one year between July 2012 and July 2014. We found a significant (p = 0.01) interaction between season and energy consumption on AL. Further inspection showed that, during the summer and winter seasons, the average allostatic load rose with relatively higher energy consumption. We also observed a linear and positive association between AL and energy intake in summer (ß = 0.0013 ± 0.0004; p = 0.001; r2 = 0.14) and winter (ß = 0.0011 ± 0.0004; p = 0.007; r2 = 0.10), but not in fall or spring. These results suggest that factors associated with distinct times of the year promote or prevent the effects of higher energy consumption on physiological stress load. Since allostatic load is linked to elevated disease risk, our results provide additional information that may help to explain seasonal differences in disease risk of some women.

Consumption of a Variety of Vegetables to Meet Dietary Guidelines for Americans' Recommendations Does Not Induce Sensitization of Vegetable Reinforcement Among Adults with Overweight and Obesity: A Randomized Controlled Trial.

BACKGROUND: Food reinforcement, or the motivation to obtain food, can predict choice and consumption. Vegetable consumption is well below recommended amounts for adults, so understanding how to increase vegetable reinforcement could provide valuable insight into how to increase consumption. OBJECTIVES: We sought to determine whether daily consumption of the Dietary Guidelines for Americans (DGA) recommendations for vegetable intake induces sensitization of vegetable reinforcement in adults with overweight and obesity. METHODS: Healthy adults with a BMI ≥ 25 kg/m2 who consumed ≤1 cup-equivalent of vegetables/day were randomly assigned to a vegetable intervention (VI; n = 55) or an attention control (AC; n = 55) group. The VI consisted of the daily provision of vegetables in the amounts and types recommended by the DGA (∼270 g/day) for 8 weeks. Participants were followed for an additional 8 weeks to assess sustained consumption. Compliance was measured weekly by resonance Raman light-scattering spectroscopy (RRS). Vegetable reinforcement was tested at weeks 0, 8, 12, and 16 using a computer choice paradigm. RESULTS: In the VI group, RRS intensity increased from week 0 to 8 (from 22,990 to 37,220), returning to baseline by week 16 (27,300). No change was observed in the AC group. There was no main effect of treatment (P = 0.974) or time (P = 0.14) and no treatment x time interaction (P = 0.44) on vegetable reinforcement. There was no moderating effect of sex (P = 0.07), age (P = 0.60), BMI (P = 0.46), delay discounting (P = 0.24), 6-n-propylthiouracil taster status (P = 0.15), or dietary disinhibition (P = 0.82) on the change in vegetable reinforcement. CONCLUSIONS: These findings suggest no effects of the provision of a variety of vegetables to meet DGA recommendations for 8 weeks on vegetable reinforcement and highlight the difficulty in increasing vegetable consumption in adults. This trial was registered at clinicaltrials.gov as NCT02585102.

Impact of beef consumption on saturated fat intake in the United States adult population: Insights from modeling the influences of bovine genetics and nutrition.

We sought to determine the impact of breed and finishing ration that reduces the saturated fat (SFA) content of beef on SFA intake (%E) in adults. Using National Health and Nutrition Examination Surveys (2001-2016), we replaced the current fatty acid profile of beef with that from two breeds (Angus, Wagyu) and three finishing rations (pasture, 15% flaxseed supplementation, 35% wet distiller's grain (WDG) supplementation). Dietary replacement levels in the model were 10%, 25%, 50%, 100%. Overall, men consumed more beef fat than women (12.0 g (11.6-12.4 g, 95%CI) and 6.6 g (6.4-6.9 g, 95%CI), respectively). The contribution of beef fat to SFA intake was 2.1%E (2.1-2.2%E, 95%CI) in men and 1.6%E (1.6-1.7%E, 95%CI) in women. SFA intake decreased with each increased replacement level for all beef types. At 100% replacement, SFA intake decreased 0.5% (Angus), 2.8% (Wagyu), 1.9% (pasture), 4.1% (flaxseed), 2.6% (WDG). Our findings demonstrate that breed and finishing ration that reduces the SFA content of beef can decrease population-level SFA intake.

Criterion-Related Validity of Spectroscopy-Based Skin Carotenoid Measurements as a Proxy for Fruit and Vegetable Intake: A Systematic Review.

Carotenoids are a category of health-promoting phytonutrients that are found in a variety of fruits and vegetables and have been used as a biomarker to approximate dietary fruit and vegetable (F/V) intake. Carotenoids are consumed, metabolized, and deposited in blood, skin, and other tissues. Emerging evidence suggests spectroscopy-based skin carotenoid measurement is a noninvasive method to approximate F/V intake. Spectroscopy-based skin carotenoid measurement overcomes bias and error inherent in self-reported dietary recall methods, and the challenges in obtaining, storing, and processing invasive blood samples. The objective of this systematic review was to examine criterion-related validity of spectroscopy-based skin carotenoid measurement as a proxy for F/V intake. The 3 methods examined were resonance Raman spectroscopy (RRS), pressure-mediated reflection spectroscopy (RS), and spectrophotometers. A comprehensive literature search of PubMed, Excerpta Medica Database (Embase), Cumulative Index of Nursing and Allied Health Literature (CINAHL), ProQuest, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials (CENTRAL) was performed in December 2018, yielding 7931 citations. Studies that examined associations between spectroscopy, blood carotenoids, and/or dietary intake were identified and reviewed independently by ≥2 reviewers to determine eligibility for inclusion. Twenty-nine articles met the inclusion criteria and all 29 studies found significant correlations or associations between spectroscopy-based skin carotenoids and plasma or serum carotenoids and/or dietary F/V intake. A majority of the studies evaluated carotenoid concentration in adults; however, 4 studies were conducted in infants and 6 studies evaluated children. Twenty studies specified the racial/ethnic groups from which the samples were drawn, with 6 including ≥20% of the sample from a minority, nonwhite population. The findings of this systematic review support the use of spectroscopy for estimating F/V intake in diverse human populations, although additional validation is needed, particularly among racially/ethnically diverse populations and populations of varying ages.

Daily Protein Intake and Distribution of Daily Protein Consumed Decreases Odds for Functional Disability in Older Americans.

Objective: We sought to determine whether daily protein intake and protein distribution across eating occasions were associated with functional disability in a national sample of older Americans. Methods: Data from 8,070 adults aged ≥60 years from the 2007-2016 waves of the National Health and Nutrition Examination Survey were included. Protein intake and functional capacity was self-reported. A daily protein recommendation of ≥1.0 g/kg/day was utilized. The daily protein recommendation was then spread-out across four meals, whereby a ≥0.25 g/kg/meal threshold was used. Results: Those meeting the daily protein recommendation had 0.78 (95% confidence interval [CI] = [0.65, 0.93]) decreased odds for functional disability. Persons meeting the protein intake threshold per eating occasion for one, two, three, and four occasions had 0.60 (CI = [0.38, 0.95]), 0.48 (CI = [0.30, 0.77]), 0.47 (CI = [0.29, 0.77]), and 0.39 (CI = [0.20, 0.75]) decreased odds for functional disability, respectively. Discussion: Protein consumption seems to be important for preserving function in older Americans.

Concurrent validity of skin carotenoid status as a concentration biomarker of vegetable and fruit intake compared to multiple 24-h recalls and plasma carotenoid concentrations across one year: a cohort study.

BACKGROUND: Biological markers of vegetable and fruit (VF) intake are needed both for nutrition surveillance and for the evaluation of nutrition interventions. Optically assessed skin carotenoid status (SCS) has been proposed as a marker of intake but there are few published validity studies to date. Therefore, the objective of the study was to examine the concurrent validity of multiple methods of assessing VF intake cross-sectionally and seasonally over one year and to discuss the relative merits and limitations of each method. METHODS: Fifty-two 40-60 y old women completed a 1-year longitudinal study that included 1) SCS assessment using resonance Raman spectroscopy (RRS) and using pressure-mediated reflection spectroscopy (RS) at 12 timepoints, 2) thirty-six 24-h recalls using the Automated Self-Administered 24-Hour Dietary Assessment Tool (ASA24; total 1866 recalls), and 3) plasma carotenoid concentrations measured every 3 months. Pearson correlation coefficients and mixed linear models were used to estimate pairwise correlations between RRS, RS, ASA24, and plasma carotenoids. RESULTS: RS and RRS were strongly correlated at baseline and over the year (r = 0.86 and 0.76; respectively, P < 0.001). RS was strongly correlated with plasma carotenoids at baseline (r = 0.70) and moderately across the year (r = 0.65), as was RRS (r = 0.77 and 0.69, respectively, all P < 0.001). At baseline, self-reported VF was weakly correlated with RRS (r = 0.33; P = 0.016), but not with RS or plasma carotenoids. Across the year, self-reported VF intake was weakly correlated with both RS (r = 0.37; P = 0.008), RRS (r = 0.37; P = 0.007), and with plasma carotenoids (r = 0.36; P < 0.008). CONCLUSIONS: SCS as measured by RS and RRS is moderately to strongly correlated with plasma carotenoid concentrations both cross-sectionally and longitudinally, indicating that it can be a powerful tool to assess carotenoid-rich VF intake in populations. CLINICAL TRIAL REGISTRY: This trial was registered at ClinicalTrials.gov as NCT01674296.

Decreasing the Consumption of Foods with Sugar Increases Their Reinforcing Value: A Potential Barrier for Dietary Behavior Change.

BACKGROUND: The Dietary Guidelines for Americans (DGA) have recommended reducing added sugar intake since its inception in 1980. Nearly 40 years later, added sugar consumption still exceeds 2015-2020 DGA recommendations among most of the population. The reinforcing value of food influences eating behaviors, and foods high in added sugars are highly reinforcing. Restricting intake of foods high in added sugars as part of a low-sugar diet may increase their reinforcing value such that reducing consumption may be difficult to maintain. If so, this would present a mechanistic barrier to making the necessary dietary changes to meet 2015-2020 DGA recommendations. PURPOSE: To determine whether the relative reinforcing value of foods high in added sugars is altered when reducing intake of all foods high in sugars. METHODS: Obese (n=19) and normal weight (n=23) men and woman who habitually consumed over 10% of their calories from added sugars completed the study. Reinforcing value of foods high in added sugars was measured via progressive ratio schedules of reinforcement before and on day 7 of a weeklong controlled feeding intervention where added sugars comprised 2.5% to 4.0% of daily calories and total sugars 7.3% to 8.6% of daily calories. RESULTS: The reinforcing value of foods high in added sugars increased (P<0.01) after consuming a diet low in total added sugars for 1 week in both obese and normal weight participants. CONCLUSION: Adhering to a low-sugar diet for 1 week increases the reinforcing value of foods high in added sugars. Future studies should examine whether consuming a diet low in added sugars, but not other sugar, increases reinforcing value of foods high in added sugars and whether high-added sugar food reinforcement returns to baseline after longer-term reductions in added sugars.

Prospective Analysis of Vegetable Amount and Variety on the Risk of All-Cause and Cause-Specific Mortality among US Adults, 1999⁻2011.

The Dietary Guidelines for Americans 2015⁻2020 (DGA) provides recommendations for consuming a specific amount and variety of vegetables, but no studies have assessed the relationship between DGA-recommended vegetable variety and risk of mortality. We prospectively assessed the relationship between vegetable amount and variety and the risk of mortality using nationally-representative survey data (n = 29,133). Hazard ratios were estimated using survey-weighted, multivariate, Cox-proportional hazards models. Mean follow-up time was 6.5 years (12.8 years maximum). Total deaths from all causes were 2861, which included 829 deaths from cardiometabolic disease (556 coronary heart disease, 170 stroke, and 103 diabetes). Compared to individuals who reported consuming the greatest amount of vegetables daily, those with the least intake had a 78% greater risk of mortality from all causes (HR: 1.78, 95% CI: 1.29⁻2.47), a 68% greater risk of death from cardiovascular disease (1.68, 1.08⁻2.62), and an 80% greater risk of death from coronary heart disease (1.80, 1.09⁻2.08). No relationships were observed between vegetable variety and risk of all-cause or cause-specific mortality. Greater vegetable amount, but not variety, was associated with a reduced risk of mortality from all causes, cardiovascular disease, and coronary heart disease. Additional large-scale longitudinal studies with repeated measures of dietary exposure are needed.

Recognition of Federal Dietary Guidance Icons Is Associated with Greater Diet Quality.

BACKGROUND: Although the purpose of federal dietary guidance is to improve eating habits, few studies have described awareness of guidance and concurrent diet quality. OBJECTIVE: The objective of the current study was to examine the prevalence of individuals who reported hearing of dietary guidance icons and to describe the association between having heard of the icons and diet quality. DESIGN: This study was a cross-sectional survey. PARTICIPANTS/SETTING: Participants (n=23,343) were from the National Health and Nutrition Examination-What We Eat in America survey 2005-2014 cycles. MAIN OUTCOME MEASURES: Awareness of the Food Guide Pyramid, MyPyramid, or MyPlate icons by sociodemographic characteristics and diet quality were measured using Healthy Eating Index (HEI) scores derived from 24-hour recall data. STATISTICAL ANALYSES PERFORMED: Global Wald tests were used to test for differences in awareness of the icons within sociodemographic groups. Total HEI scores were calculated using the population-ratio method. Z-scores were used to test differences in HEI total scores between those with knowledge of the icons and those who responded negatively. RESULTS: In all cycles, those with less than a high school diploma were the least likely to report having heard of the icons (P<0.001). In every wave except 2011 to 2012, participants with low or marginal food security status were less likely to report affirmatively (P<0.001), and Supplemental Nutrition Assistance Program (SNAP) participants and SNAP-eligible nonparticipants were least likely to report having heard of the icons (P<0.001) except for 2005 to 2006. HEI scores were higher among those who had heard of MyPyramid in 2007-2012 (P<0.05) and MyPlate in 2013-2014 (P<0.001) compared with those who had not heard of the icon. CONCLUSIONS: Recognition of federal dietary guidance icons was associated with higher diet quality recently, but the cross-sectional nature of the data precludes conclusions of causality. Further research is needed to identify barriers and promoters for translating awareness of the federal dietary guidance icons into healthful food purchasing and food consumption decisions.

Americans' Perceptions about Fast Food and How They Associate with Its Consumption and Obesity Risk.

We aimed to systematically examine Americans' perceptions of fast food (FF) and how these perceptions might affect fast food consumption (FFC) and obesity risk. We searched PubMed and Google for studies published in English until February 17, 2017 that reported on Americans' perceptions (defined as their beliefs, attitudes, and knowledge) regarding FF as well as those on their associations with FFC and obesity risk. Thirteen articles met inclusion criteria. Limited research has been conducted on these topics, and most studies were based on convenience samples. A 2013 nationally representative phone survey of about 2000 subjects showed that one-fifth of Americans thought FF was good for health, whereas two-thirds considered FF not good. Even over two-thirds of weekly FF consumers (47% of the total population) thought FF not good. Americans seem to have limited knowledge of calories in FF. Negative and positive FF perceptions were associated with FFC. Those who consumed less FF seemed more likely to view FF negatively. When Americans valued the convenience and taste of FF and preferred FF restaurants with kid's menus and play areas, they were likely to purchase more FF. Available research indicates neither perceived availability of FF nor Geographical Information System (GIS)-based FF presence in the neighborhood has significant associations with weekly FFC. No studies examined potential links between FF perceptions and obesity risk. Americans' perceptions of FF and how they might associate with FFC and obesity risk are understudied. Considerable variation was observed in Americans' perceptions and FFC.

Modeled replacement of traditional soybean and canola oil with high-oleic varieties increases monounsaturated fatty acid and reduces both saturated fatty acid and polyunsaturated fatty acid intake in the US adult population.

BACKGROUND: High-oleic (HO) seed oils are being introduced as replacements for trans fatty acid (TFA)-containing fats and oils. Negative health effects associated with TFAs led to their removal from the US Generally Recognized As Safe list. HO oils formulated for use in food production may result in changes in fatty acid intake at population levels. Objectives: The purposes of this study were to 1) identify major food sources of soybean oil (SO) and canola oil (CO), 2) estimate effects of replacing SO and CO with HO varieties on fatty acid intake overall and by age and sex strata, and 3) compare predicted intakes with the Dietary Reference Intakes and Adequate Intakes (AIs) for the essential fatty acids (EFAs) α-linolenic acid (ALA) and linoleic acid (LA). Design: Food and nutrient intakes from NHANES waves 2007-2008, 2009-2010, 2011-2012, and 2013-2014 in 21,029 individuals aged ≥20 y were used to model dietary changes. We estimated the intake of fatty acid with the replacement of HO-SO and HO-CO for commodity SO and CO at 10%, 25%, and 50% and evaluated the potential for meeting the AI at these levels. RESULTS: Each modeling scenario decreased saturated fatty acids (SFAs), although intakes remained greater than recommended for all age and sex groups. Models of all levels increased the intake of total monounsaturated fatty acids (MUFAs), especially oleic acid, and decreased the intake of total polyunsaturated fatty acids (PUFAs), particularly LA and ALA. Replacement of traditional with HO oils at 25-50% places specific adult age and sex groups at risk of not meeting the AI for LA and ALA. Conclusions: The replacement of traditional oils with HO varieties will increase MUFA intake and reduce both SFA and PUFA intakes, including EFAs, and may place specific age and sex groups at risk of inadequate LA and ALA intake.

Depletion and repletion of fruit and vegetable intake alters serum bone turnover markers: a 28-week single-arm experimental feeding intervention.

This study was designed to evaluate the effects of elevated fruit and vegetable intake on bone turnover markers. In all, twenty-nine subjects (nine male and twenty female, with a mean age of 32·1 (sem 2·5) years) participated in a 28-week single-arm experimental feeding intervention trial and consumed a prescribed low-fruit and vegetable diet for 6 weeks (depletion-1), a provided high-fruit and vegetable diet for 8 weeks (fruit: 360-560 g; vegetables: 450-705 g), another prescribed low-fruit and vegetable diet for 6 weeks (depletion-2) and then their usual diets for 8 weeks (repletion). Serum bone-related biomarkers were analysed with commercial ELISA kits. Plasma carotenoid levels decreased as a result of the depletion phase and increased with the high-fruit and vegetable diet. Compared with the baseline, depletion-1 resulted in higher serum bone resorption marker C-terminal telopeptide of type 1 collagen (CTX) and lower bone formation marker alkaline phosphatase (BAP) (CTX, 0·68 (sem 0·05) v. 0·97 (sem 0·08) ng/ml and BAP, 10·7 (sem 0·7) v. 9·5 (sem 0·8) µg/l for the baseline and the depletion-1, respectively, P<0·05). High intake of fruit and vegetables decreased serum CTX (P<0·05) to 0·60 (sem 0·04) ng/ml and increased serum BAP to 11·3 (sem 0·7) µg/l (P<0·05), compared with the depletion-1 phase. Serum concentrations of CTX were inversely correlated and those of BAP were positively correlated with blood lycopene. These data show that increased fruit and vegetable consumption at or above federal dietary guidance may be beneficial to bone health.

Study design for a clinical trial to examine food price elasticity among participants in federal food assistance programs: A laboratory-based grocery store study.

We present a protocol for a study investigating the effect of food price changes on purchasing decisions among individuals participating in federal food assistance programs and among those not participating in these programs. We use a laboratory-based grocery store design, which provides greater control over factors influencing food purchasing than in situ experiments in actual grocery stores. We focus primarily, but not exclusively, on eggs because they are highly nutritious, easy to prepare, can be included in many different dishes, and are a part of a wide range of cultural food menus. The primary aim of this study is to compare the own-and cross-price elasticity of eggs between individuals participating in federal food assistance programs and those not participating in these programs. Our secondary aims are to 1) compare the own- and cross-price elasticity of eggs between overweight/obese individuals and non-overweight/obese individuals, 2) examine whether delay discounting moderates the effect of income on own- and cross-price elasticity, 3) examine whether subjective social status moderates the effect of participation in federal food assistance programs on the purchase of high nutrient-dense foods, and 4) examine whether usual psychological stress level moderates the effect of subjective social status on the purchase of high-nutrient dense foods. The results of this study will provide information about the drivers of food demand among low-income adults. A better understanding of these drivers is needed to develop effective nutrition interventions for this large population.

Capacity of the US Food System to Accommodate Improved Diet Quality: A Biophysical Model Projecting to 2030.

BACKGROUND: Increasing Americans' diet quality will require changes to the food supply. Due to the complex nature of the food system, this is not as straightforward as simply increasing the production of healthy foods and decreasing the production of unhealthy foods. Little is known about whether the US food system can produce enough food, given finite agricultural resources, to support shifts toward healthier eating patterns. OBJECTIVE: The aim of this study was to model the capacity of the US food system to accommodate a shift toward a healthier diet by 2030. METHODS: A biophysical simulation model estimated the proportion of the US population that could be fed a given diet based on food system constraints, currently and projected to 2030. The model accepted data inputs on food intake, crop yields, and population size. Linear and nonlinear regression models were used to estimate projected food intake and crop yields based on recent historical data (1980-2014). Diet quality was estimated using the Healthy Eating Index-2015. RESULTS: The US agricultural system can produce enough food to feed 146% of the population by 2030. A greater proportion of the population can be fed a high-quality diet than a low-quality diet (178% compared to 119%). To accommodate increased diet quality, substantial increases in cropland acreage would be needed for fruits (P < 0.001), vegetables (P = 0.002), legumes (P = 0.002), and nuts (P = 0.007); and decreased cropland acreage would be needed for grains (P = 0.002) and sweeteners (P < 0.001). CONCLUSIONS: The US can produce more than enough food to accommodate a shift toward a healthier diet pattern, but even moderate shifts in diet quality would require major transitions in cropland use. The success of this transition is dependent on several factors, like individuals' ease of entry into the agricultural sector, producers' ability to shift production to other crops, and modifications to the food supply chain.

Greater vegetable variety and amount are associated with lower prevalence of coronary heart disease: National Health and Nutrition Examination Survey, 1999-2014.

BACKGROUND: The 2015-2020 Dietary Guidelines for Americans (DGA) provides specific intake recommendations for vegetable variety and amount in order to protect against chronic disease. However, to the best of our knowledge, no studies have examined the link between DGA recommended vegetable variety and cardiometabolic disease. To address this research gap, our aim was to estimate the relationship between vegetable variety, vegetable amount, and prevalent cardiometabolic disease subtypes, and to assess potential determinants of vegetable variety. METHODS: Data on food intake and reported cardiometabolic disease status were acquired for 38,981 adults from the National Health and Nutrition Examination Survey (1999-2014). Vegetable variety was measured using a modified dietary diversity index that was adjusted for the potential confounding effects of vegetable amount. Temporal trends in vegetable variety and amount were assessed using univariate linear regression models. Multivariate logistic regression models were used to estimate the relationship between vegetable variety and prevalent disease, and between vegetable amount and prevalent disease. Multivariate ordered logistic regression models were used to assess the relationship between vegetable variety and explanatory variables. RESULTS: Overall, vegetable variety decreased (P = 0.035) from 1999 to 2014, but vegetable amount did not (P = 0.864). Intake of starchy vegetables decreased (P < 0.001), and intake of dark green vegetables increased (P < 0.001) over this 16-year period, but no trends were observed for other subgroups. An inverse linear relationship was observed between vegetable variety and prevalent coronary heart disease (P-trend = 0.032) but not other prevalent diseases; and between vegetable amount and coronary heart disease (P-trend = 0.026) but not other prevalent diseases. Individuals who reported consuming dark green vegetables had lower odds of having cardiovascular disease (0.86, 95% CI: 0.74-0.99) and coronary heart disease (0.78, 0.65-0.94) compared to individuals who reported not consuming any green vegetables. Living with a domestic partner was associated with greater vegetable variety (P = < 0.001), and currently smoking was associated with lower vegetable variety (P = < 0.001). Vegetable variety and amount were positively associated (P < 0.001). CONCLUSIONS: Vegetable variety and amount were inversely associated with prevalent coronary heart disease. Vegetable variety was strongly associated with vegetable amount, likely mediated by reduced habituation and increased liking. Increasing vegetable variety and amount are still important messages for the public.