Secular trends in regional differences in nutritional biomarkers and self-reported dietary intakes among American adults: National Health and Nutrition Examination Survey (NHANES) 1988-1994 to 2009-2010.

OBJECTIVE: To understand the contribution of regional differentials in dietary exposures to regional gradients in health, we examined 20-year trends in the association of US census region of residence with nutritional biomarkers and dietary intakes of American adults. DESIGN: Observational. SETTING: The biomarker and 24 h dietary recall data were from the National Health and Nutrition Examination Surveys (NHANES) conducted during 1988-1994 and 1999-2010. The US census region was operationalized as Northeast, Midwest, South and West. Nutritional biomarker outcomes were serum folate, vitamins B6, B12, C, D and E, and carotenoids; dietary outcomes were intakes of nutrients, food groups and eating patterns. SUBJECTS: US adults, n>8000-40 000 for biomarkers and >43 000 for dietary outcomes. RESULTS: The interactions of survey time period and region were not significant for the examined biomarker and dietary outcomes, indicating similar secular trends among regions. The main effect of region was significant for all nutritional biomarkers except serum vitamin B6, most dietary micronutrients, food groups and eating patterns (P<0·001). The mean serum folate, vitamins B12, C and E, and all carotenoid (except lycopene) biomarker levels, and intakes of dietary fibre, vitamins A, E, C and B6, folate, K, Ca, Mg and Fe, fruits, vegetables and whole grains, were higher in the West and Northeast regions, relative to the South and Midwest regions. CONCLUSIONS: Overall, the regional gradients in dietary exposure, expressed objectively as biomarkers or as self-reported nutrient and food group intakes, paralleled trajectories reported for health outcomes and were remarkably persistent over time.

Family income and education were related with 30-year time trends in dietary and meal behaviors of American children and adolescents.

Recent survey data reveal the persistence of long-acknowledged socioeconomic status (SES) differentials in the prevalence of obesity in U.S. children and adolescents. We examined 30-y changes in the association of dietary and meal behaviors with family income and education to understand the possible contribution of these trends to SES trends in obesity rates in 2- to 19-y-old Americans. We used dietary and SES data for 2- to 19-y olds from the NHANES 1971-1974 to 2003-2008 (n = 39,822). The secular changes in the independent association of family income and education with 24-h dietary behaviors [energy intake (kcal), amount of foods and beverages (g), percent energy from all beverages and from nutritive beverages, and energy density of foods] and 24-h meal behaviors [number of eating occasions, energy from snack episodes (%), and mention of breakfast] were examined using multivariable regression methods. The secular increase in energy intake and food and beverage amount was significant in the lowest family SES categories. The positive association of family income and education with intakes of energy, food amounts, and beverage energy, noted in 1971-1974 or 1976-1980, was not observed in later surveys. There was an age gradient in changes in most diet and SES associations over time, with largest adverse changes in 12- to 19-y olds. Higher education was associated with lower energy from snack episodes, breakfast skipping, and energy density of foods and these associations did not change over time. Overall, these results suggest both income and education differentials in secular increases in food amounts and energy intakes.

Race-ethnic, family income, and education differentials in nutritional and lipid biomarkers in US children and adolescents: NHANES 2003-2006.

BACKGROUND: Children from ethnic minority and low-income families in the United States have higher rates of poor health and higher mortality rates. Diet, an acknowledged correlate of health, may mediate the known race-ethnic and socioeconomic differentials in the health of US children. OBJECTIVE: The objective was to examine the independent association of race-ethnicity, family income, and education with nutritional and lipid biomarkers in US children. DESIGN: We used data from the NHANES 2003-2006 to examine serum concentrations of vitamins A, D, E, C, B-6, and B-12; serum concentrations of folate, carotenoids, and lipids; and dietary intakes of corresponding nutrients for 2-19-y-old children (n = ~2700-7500). Multiple covariate-adjusted regression methods were used to examine the independent and joint associations of race-ethnicity, family income, and education with biomarker status. RESULTS: Non-Hispanic blacks had lower mean serum concentrations of vitamins A, B-6, and E and α-carotene than did non-Hispanic whites. Both non-Hispanic blacks and Mexican Americans had higher mean serum vitamin C, ß-cryptoxanthin, and lutein + zeaxanthin but lower folate and vitamin D concentrations compared with non-Hispanic whites. In comparison with non-Hispanic whites, non-Hispanic blacks were less likely to have low serum HDL cholesterol or high triglycerides. Family income and education predicted few biomarker or dietary outcomes, and the observed associations were weak. Moreover, modification of race-ethnic differentials by income or education (or vice versa) was noted for very few biomarkers. CONCLUSION: Race-ethnicity, but not family income or education, was a strong independent predictor of serum nutrient concentrations and dietary micronutrient intakes in US children and adolescents.

20-Year trends in dietary and meal behaviors were similar in U.S. children and adolescents of different race/ethnicity.

Recent survey data reveal persistent race/ethnic disparities in prevalence of adiposity in U.S. children and adolescents. We examined race/ethnic differentials in time trends in dietary behaviors of Americans 2-19 y of age to understand if these trends track those observed for body weight. We used dietary data from the NHANES 1988-1994, 1999-2002, and 2003-2008 (n = 24,131) to examine changes in reported energy intake, amount of foods and beverages, number of eating occasions, and percent of energy from foods and beverages, among non-Hispanic white, non-Hispanic black, and Mexican American 2-19 y olds. Multivariable regression analyses appropriate for complex surveys were used to examine these associations. The secular increase in mean number of eating occasions was significant (P-trend < 0.0001) in all age and race/ethnic groups; however, a corresponding increase in the amount of foods and beverages, or total energy intake was not observed. In non-Hispanic black and Mexican American 2-5 and 12-19 y olds, the secular increase in number of eating occasions, and in non-Hispanic black 12-19 y olds, the increase in percent of energy from all beverages or non-nutritive beverages were greater relative to non-Hispanic whites. In conclusion, the observed race/ethnic differences in trajectory of changes in dietary behaviors over past 20 y were modest and were not accompanied by a significant increase in energy intake. Cautious interpretation is urged due to potential underreporting of dietary intake in national surveys. There was a suggestion of convergence in some race/ethnic differentials in dietary behaviors due to greater relative changes in possibly adverse behaviors in non-Hispanic blacks, especially adolescents.

Contributors of water intake in US children and adolescents: associations with dietary and meal characteristics--National Health and Nutrition Examination Survey 2005-2006.

BACKGROUND: Little is known about the association of contributors of total water intake with dietary characteristics in US children. OBJECTIVE: We examined intakes of total water and its contributors and their associations with diet and meal reporting in children and adolescents. DESIGN: Dietary data for children 2-19 y of age (n = 3978) from the National Health and Nutrition Examination Survey 2005-2006 were used to compute usual intake of total water. The association of total water and its contributors with sociodemographic characteristics and dietary and meal attributes was examined by using multiple regression analysis. RESULTS: The adjusted mean intakes of total water in Americans aged 2-5, 6-11, and 12-19 y were 1.4, 1.6, and 2.4 L, respectively. The mean usual intake of total water was generally less than the Adequate Intake; overall, more boys reported intakes of at least the Adequate Intake. The percentage of total water intake from plain water increased with age. Plain water intake was inversely associated with the intake of beverage moisture and the energy density of foods; conversely, beverage moisture was positively associated with dietary energy, fat, and the energy density of foods. Associations of water contributors with meal patterns (number of eating occasions, reporting of breakfast or snack) were inconsistent across age groups. Nearly 80% of food moisture, >66% of beverage moisture, and ≈30% of plain water were reported with main meals. CONCLUSIONS: Intake of total water over 24 h from different contributors varied by age. Qualitative differences in dietary intake in association with the amount of plain water and beverage moisture in the recalls were observed. American children and adolescents consumed more than two-thirds of their daily beverages with main meals.

Patterns of recommended dietary behaviors predict subsequent risk of mortality in a large cohort of men and women in the United States.

Recommendations for intake of fruits and vegetables, whole grains, lean meats, and low-fat dairy form the underpinning of dietary guidance for health promotion. We examined the association of a summary index of food consumption behaviors compatible with the spirit of prevailing dietary guidance and mortality. We used data from the NIH-American Association of Retired Persons cohort (n = 350,886), aged 50-71 y and disease free at baseline in 1995-1996, to examine the association of a dietary behavior score (DBS) with mortality after 10.5 y of follow-up (deaths, n = 29,838). The DBS included 6 equally weighted components derived from responses to questions on usual dietary behaviors related to consumption of fruits, vegetables, low-fat dairy, whole grains, lean meat and poultry, and discretionary fat. The covariate-adjusted association of DBS and mortality from all causes, cancer, and coronary heart disease was examined using Cox proportional hazards regression methods. Compared with those in the lowest one-fifth of DBS, the multivariate-adjusted relative risk of mortality in the highest one-fifth of the DBS was 0.75 (95% CI, 0.70-0.80) in women and 0.79 (95% CI, 0.75-0.83) in men (P-trend < 0.0001). The inverse association of DBS and mortality was significant in both genders in nearly all categories of covariates. Similar trends were observed for DBS associations with mortality from cancer and heart disease. Nearly 12% of the covariate-adjusted population risk of mortality was attributable to nonconformity with dietary recommendations. Adoption of recommended dietary behaviors was associated with lower mortality in both men and women independent of other lifestyle risk factors.

Ethnic and socioeconomic differences in variability in nutritional biomarkers.

BACKGROUND: Several studies have reported ethnic, education, and income differentials in concentrations of selected nutritional biomarkers in the US population. Although biomarker measurements are not subject to biased self-reports, biologic variability due to individual characteristics and behaviors related to dietary exposures contributes to within-subject variability and measurement error. OBJECTIVE: We aimed to establish whether the magnitude of components of variance for nutritional biomarkers also differs in these high-risk groups. DESIGN: We used data from 2 replicate measurements of serum concentrations of vitamins A, C, D, and E; folate; carotenoids; ferritin; and selenium in the third National Health and Nutrition Examination Survey second examination subsample (n = 948) to examine the within-subject and between-subject components of variance. We used multivariate regression methods with log-transformed analyte concentrations as outcomes to estimate the ratios of the within-subject to between-subject components of variance by categories of ethnicity, income, and education. RESULTS: In non-Hispanic blacks, the within-subject to between-subject variance ratio for beta-cryptoxanthin concentration was higher (0.23; 95% CI: 0.17, 0.29) relative to non-Hispanic whites (0.13; 0.11, 0.16) and Mexican Americans (0.11; 0.07, 0.14), and the lutein + zeaxanthin ratio was higher (0.29; 0.21, 0.38) relative to Mexican Americans (0.15; 0.10, 0.19). Higher income was associated with larger within-subject to between-subject variance ratios for serum vitamin C and red blood cell folate concentrations but smaller ratios for serum vitamin A. Overall, there were few consistent up- or down-trends in the direction of covariate-adjusted variability by ethnicity, income, or education. CONCLUSION: Population groups at high risk of adverse nutritional profiles did not have larger variance ratios for most of the examined biomarkers.

Ethnicity is an independent correlate of biomarkers of micronutrient intake and status in American adults.

Diet may be among the factors that mediate the acknowledged ethnicity and socioeconomic differentials in health. Biomarkers of nutritional exposure avoid reliance on biased self-reports of diet and allow an objective assessment of dietary differentials associated with ethnicity and socioeconomic position. We used data from the NHANES III (n = 13113) and NHANES 1999-2002 (n = 7246) to examine ethnic, education, and income differentials in serum concentrations of nutrients of putative public health importance (vitamins C, D, and E, folate, carotenoids, selenium, and ferritin) in U.S. adults. Multiple regression methods were used to adjust for covariates and complex survey design to examine these associations. The serum beta-cryptoxanthin and lutein + zeaxanthin concentrations, adjusted for education and income, were higher in nonwhites (P < 0.0001) relative to non-Hispanic whites. Non-Hispanic blacks had lower serum vitamins C and D, folate, and selenium concentrations relative to non-Hispanic-whites. The biomarker profile (except vitamin D, and folate and ferritin in women) of Mexican-Americans was comparable or better relative to non-Hispanic-whites. Ethnicity associations with mean biomarker concentrations generally paralleled these associations with the proportion of the population at risk of marginal concentrations. Education was an independent positive predictor of serum concentrations of several carotenoids and vitamin C (P

Trends in black-white differentials in dietary intakes of U.S. adults, 1971-2002.

BACKGROUND: Disparities in the health status of blacks and whites have persisted despite considerable gains in improved health of the U.S. population. Tracking changes in black-white differentials in dietary attributes over time may help in understanding the contribution of diet to these disparities. METHODS: Data were used from four National Health and Nutrition Examination Surveys conducted between 1971 and 2002 for trends in self-reported intakes of energy, macronutrients, micronutrients, fruits and vegetables, and the energy density of foods among U.S. non-Hispanic black (n=7099) and white (n=23,314) men and women aged 25 to 74 years. Logistic and linear regression methods were used to adjust for multiple covariates and survey design. RESULTS: Energy intake, amount of food, and carbohydrate energy increased, whereas percentage of energy from protein, fat, and saturated fat decreased over time in all race and gender groups (p<0.001). In whites and in black women, energy density increased (p<0.001) in parallel to increases in obesity prevalence. In all surveys, black men and women reported lower intakes of vegetables, potassium, and calcium (p<0.001) than their white counterparts. In men, the race differential in calcium intake increased across surveys (p=0.004). CONCLUSIONS: Dietary intake trends in blacks and whites from 1971 to 2002 were similar, which suggests that previously identified dietary risk factors that differentially affect black Americans have not improved in a relative sense.

Secular trends in the association of socio-economic position with self-reported dietary attributes and biomarkers in the US population: National Health and Nutrition Examination Survey (NHANES) 1971-1975 to NHANES 1999-2002.

OBJECTIVE: Recent reports suggest persistence of health disparities related to socio-economic position (SEP). To understand if diet may be a contributor to these trends, we examined secular trends in the association of diet and indicators of SEP from 1971-1975 to 1999-2002. DESIGN: We used data from the National Health and Nutrition Examination Surveys (NHANES) I (1971-1975), II (1976-1980), III (1988-1994) and 1999-2002 to examine the independent associations of poverty income ratio (PIR) and education with diet and biomarkers of diet and disease in 25-74-year-olds (n = 36,600). We used logistic and linear regression methods to adjust for multiple covariates and survey design to examine these associations. RESULTS: A large PIR differential in the likelihood of reporting a fruit or all five food groups and vitamin C intake, and an education differential in likelihood of obesity and carbohydrate intake, was noted in 1971-1975 but narrowed in 1999-2002 (P < 0.007). The positive association of education with intake of a fruit, vegetable or all five food groups, vitamins A and C, calcium and potassium intake remained unchanged across surveys (P < 0.001). Similarly, the positive association of PIR with the amount of foods and intakes of energy and potassium remained unchanged over three decades (P < 0.001). The education and the PIR differential in energy density, and the PIR differential in the likelihood of obesity, persisted over the period of the four surveys (P < 0.001). CONCLUSIONS: Persistence of unfavourable dietary and biomarker profiles in Americans with low income and education suggests continued need for improvement in the quality of diets of these high-risk groups.

A comparison of three dietary pattern indexes for predicting biomarkers of diet and disease.

OBJECTIVE: Examination of dietary indexes in association with objective biomarkers of dietary intake and chronic disease risk is an important step in their validation. We compared three dietary pattern indexes-Healthy Eating Index (HEI), Recommended Foods Score (RFS-24 hour recall), and Dietary Diversity Score for recommended foods (DDS-R)-for their ability to predict biomarkers of dietary intake, obesity, cardiovascular disease, and diabetes. METHODS: We used dietary and laboratory data from the third National Health and Nutrition Examination Survey to study these associations in 8719 disease-free adults aged > or =20 y. The HEI, developed by the USDA, was a sum of scores on consideration of ten individual components; the RFS was a sum of all recommended foods (lean meat, poultry and fish, whole grains, fruits and juices, low-fat dairy, and vegetables) mentioned in the recall; the DDS-R examined whether or not a recommended food was mentioned from each of the five major food groups. The independent association of the dietary pattern indexes with body mass index (BMI), blood pressure, and serum concentrations of several biomarkers were examined using regression methods to adjust for multiple covariates. RESULTS: All indexes were strong independent positive predictors of serum concentrations of vitamin C, E, folate, and all carotenoids (p < or = 0.00001), except lycopene, and were negative predictors of BMI, serum homocysteine, C-reactive protein, plasma glucose, and hemoglobin A1C (p < 0.05). The RFS and DDS-R were inversely associated with blood pressure and serum cholesterol (p < or = 0.03). CONCLUSIONS: The RFS and DDS-R performed as well or better than the HEI for predicting serum concentration of nutrients and biomarkers of disease risk.

Dietary patterns and health outcomes.

A systematic review of the literature on dietary patterns (multiple dietary components operationalized as a single exposure) in relation to nutrient adequacy, lifestyle and demographic variables, and health outcome was conducted. Most of the published reports on the subject have used one of two methods to determine dietary patterns: (a) diet indexes or scores that assess compliance with prevailing dietary guidance as dietary patterns, and (b) data-driven methods that use factor or cluster analysis to derive dietary patterns. Irrespective of the approach used, patterns characterized by fruit/vegetable/whole grain/fish/poultry consumption generally have been reported to relate to micronutrient intake, and to selected biomarkers of dietary exposure and disease risk in the expected direction. Age, income, and education have been reported to be among positive predictors of the so-called more healthful dietary patterns. An inverse association of healthful dietary patterns with all-cause mortality and cardiovascular disease risk was reported in most studies. However, the magnitude of risk reduction was modest and was attenuated after control for confounders. Few published studies showed an association between risk of most incident cancers and dietary patterns. Both of the currently used approaches for extracting dietary patterns have limitations, are subject to dietary measurement errors, and have not generated new diet and disease hypotheses.

Predictors of reported consumption of low-nutrient-density foods in a 24-h recall by 8-16 year old US children and adolescents.

The purpose of this study was to develop an explanatory model to predict the number of low-nutrient-density (LND) foods reported in a 24-h recall by US children and adolescents using data from the third National Health and Nutrition Examination Survey. The reported number of LND foods was estimated from 24-h dietary recall data for 8-16 year old respondents (n=4137; 2024 males and 2113 females). The LND foods included--baked and dairy desserts, sweeteners, salty snacks, visible/discretionary fat, and miscellaneous. The predictive ability of socio-demographic, family, weight/dieting related, life-style or food consumption related subject characteristics was determined using multiple linear regression analyses. The strongest independent negative predictor of the reported number of LND foods was the amount of nutrient-dense foods from the five major food groups. In addition, number of eating occasions reported was a significant independent positive predictor, and the weekly frequency of consuming a complete school lunch was a significant independent negative predictor of the reported number of LND foods. These models explained approximately 55% of the variance in LND food reporting in both males and females. Socio-demographic, family, body weight, or lifestyle characteristics contributed little to predicting the number of LND foods reported in a 24-h recall.