Methodology for Adding Glycemic Index to the National Health and Nutrition Examination Survey Nutrient Database

Generating valid estimates of dietary glycemic index (GI) and glycemic load (GL) has been a challenge in nutritional epidemiology. The methodologic issues may have contributed to the wide variation of GI/GL associations with health outcomes observed in existing literature. We describe a standardized methodology for assigning GI values to items in the National Health and Nutrition Examination Survey (NHANES) nutrient database using the new International Tables to develop research-driven, systematic procedures and strategies to estimate dietary GI/GL exposures of a nationally representative population sample. Nutrient databases for NHANES 2003-2006 contain information on 3,155 unique foods derived from the US Department of Agriculture National Nutrient Database for Standard Reference versions 18 and 20. Assignment of GI values were made to a subset of 2,078 carbohydrate-containing foods using systematic food item matching procedures applied to 2008 international GI tables and online data sources. Matching protocols indicated that 45.4% of foods had identical matches with existing data sources, 31.9% had similar matches, 2.5% derived GI values calculated with the formula for combination foods, 13.6% were assigned a default GI value based on low carbohydrate content, and 6.7% of GI values were based on data extrapolation. Most GI values were derived from international sources; 36.1% were from North American product information. To confirm data assignments, dietary GI and GL intakes of the NHANES 2003-2006 adult participants were estimated from two 24-hour recalls and compared with published studies. Among the 3,689 men and 4,112 women studied, mean dietary GI was 56.2 (men 56.9, women 55.5), mean dietary GL was 138.1 (men 162.1, women 116.4); the distribution of dietary GI was approximately normal. Estimates of population GI and GL compare favorably with other published literature. This methodology of adding GI values to an existing population nutrient database utilized systematic matching protocols and the latest comprehensive data sources on food composition. The database can be applied in clinical and survey research settings where there is interest in estimating individual and population dietary exposures and relating them to health outcomes.     

Diet diversity and nutrient intake

Variety is espoused as a key to dietary adequacy, yet data from new shortcut dietary measures suggest that intakes of relatively few foods can accurately classify individuals according to nutrient intake. This study examines diet diversity, caloric intake, and nutrient density values as contributors to the level of selected nutrients in the diets of 1,747 white men and 1,898 white women, 18 to 34 years old, completing the 24-hour recall in NHANES II. Nutrient intake was directly related to both number of foods eaten and total calories consumed, as well as to nutrient density values. For fat, saturated fat, and potassium, higher caloric consumption alone may account for substantial differences in nutrient intakes between the lowest and highest quartiles. For cholesterol, calcium, and vitamin A, differences in dietary density were more important in explaining nutrient intake differences. Both caloric intake and nutrient density influence sodium intake from food sources. For some nutrients, an overall measure of diversity may be useful for estimating intakes. For others, nutrient-specific diversity indexes would likely be needed. Knowledge of specific foods in diets with high levels of nutrients could aid the construction of food frequency instruments.     

Agreement on nutrient intake between the databases of the First National Health and Nutrition Examination Survey and the ESHA Food Processor

The objective of this study was to assess agreement on nutrient intake between the nutrient database of the First National Health and Nutrition Examination Survey (NHANES I) and an up-to-date (December 1998) nutrient database, the ESHA Food Processor. Analysis was conducted among 11,303 NHANES I participants aged 25-74 years in 1971-1975 who had undergone dietary assessment. A list of all unique foods consumed was obtained from a single 24-hour dietary recall questionnaire administered during the baseline NHANES I visit. Foods on the list were matched to foods in the ESHA Food Processor software. Agreement between participants' nutrient intakes as calculated with the NHANES I and ESHA nutrient databases was assessed using intraclass correlation analysis, linear regression analysis, and graphic methods. Intraclass correlation analysis demonstrated excellent concordance between most nutrient intakes, with coefficients above 0.95 for intakes of energy, carbohydrates, protein, cholesterol, and calcium; coefficients between 0.90 and 0.95 for intakes of total fat, saturated fat, potassium, and vitamin C; and coefficients of approximately 0.85 for intakes of sodium and vitamin A. Graphic methods and regression analyses also showed good-to-excellent correspondence for most nutrients. These findings support the validity of expanding existing nutrient intake databases to explore current hypotheses, provided that food formulation, enrichment, and fortification practices have not changed substantially over time.     

Estimated nutrient intakes and adequacies in Bangladesh change when newer values for vitamin A, iron and calcium in commonly consumed foods are applied

A food consumption survey was conducted in rural Bangladesh in January-March 1996 using a 24-h food weighing method. Intakes and adequacies of energy, vitamin A, vitamin C, iron and calcium were estimated for 81 children (aged 24-71 months) and 182 women (aged 18-45 years) using three sets of food composition tables. The local food composition table was modified with newer values for nutrient contents of foods identified as important for the contribution of vitamin A and iron. Significant differences in estimated dietary intakes and adequacies were found for vitamin A and iron when different sets of food composition values were used. This study shows that up-to-date chemical analyses of foods selected on the basis of a high frequency of consumption and a large contribution of the nutrients in focus is a useful approach in improving the quality of food composition tables, resulting in greater accuracy of estimates of nutrient intakes and adequacies.     

Dairy consumption and related nutrient intake in African-American adults and children in the United States: continuing survey of food intakes by individuals 1994-1996, 1998, and the National Health And Nutrition Examination Survey 1999-2000

OBJECTIVE: To establish the first baseline of dairy and related nutrient intake in African Americans, an at-risk population of public health concern in the United States. To document dairy consumption in African Americans by age and sex during 1994-1998 and 1999-2000 and compare it with concomitant dairy, calcium, and related nutrient intakes in non-African-American adults and children. DESIGN: Duplicate and single 24-hour recalls were analyzed to determine dietary intake during the Continuing Survey of Food Intakes by Individuals 1994-1996, 1998 (CSFII), and the National Health and Nutrition Examination Survey 1999-2000 (NHANES), respectively. SUBJECTS: African Americans and non-African Americans of all ages who participated in CSFII 1994-1996, 1998, and in NHANES 1999-2000; both surveys are a stratified random sample of the total civilian, noninstitutionalized US population. STATISTICAL ANALYSIS: Dairy food and nutrient intake per day were quantified according to age, sex, and ethnicity/race from CSFII 1994-1996, 1998, and NHANES 1999-2000. For NHANES, mean intakes from 1-day food records were sample-weighted, and standard errors estimated by the Taylor linearization method of SUDAAN (version 9.0, 2004, RTI International, Research Triangle Park, NC). Usual daily intakes of calcium, magnesium, and phosphorus were based on 2-day intake data from CSFII 1994-1996, 1998, and calculated using Software for Intake Distribution from Iowa State University. The percentage of individuals categorized as not meeting the Estimated Average Requirement for magnesium and phosphorus were calculated in the same way. RESULTS: CSFII 1994-1996, 1998, and NHANES 1999-2000 data both show that African Americans in all age groups consume fewer mean servings per day of total dairy, milk, cheese, and yogurt than non-African Americans, and have lower mean intakes of calcium, magnesium, and phosphorus. Significant differences were seen for men and women. CONCLUSIONS: In this analysis, young African-American women did not meet Dietary Reference Intakes for phosphorus, and all African Americans did not meet Dietary Reference Intakes for calcium and magnesium. African Americans in all age groups did not meet dairy recommendations from the 2005 US Dietary Guidelines and the 2004 National Medical Association Consensus Report on the role of dairy and dairy nutrients in the diet of African Americans.     

Nutrient intakes of older infants: effect of different milk feedings

Using 24-hour dietary and nutrient intake of 293 infants 7-12 months of age from NHANES II, 1976-80, we determined the hypothetical effects of different milk feedings on total intake of 12 nutrients. Infants were grouped by age at 7-8, 9-10, and 11-12 months. Human milk (HM), Fe-fortified infant formula (I-FM), whole cow's milk (WCM), and 2% lowfat milk (2%) were substituted to provide the same energy as that calculated from the difference between median energy intake provided by solid foods and the total diet. Nutrients from milk feedings were added to median nutrient intake from solid foods. Use of WCM or 2% resulted in low total intakes of Fe (6.3-11.1 mg) and linoleic acid (0.5-2.5 g) and high intakes of protein (32-47 g), Na (630-1,200 mg), K (1,400-1,900 mg), and Ca (920-1,170 mg) relative to the RDA. Feeding of HM provided total intakes that met the RDA for each nutrient except Fe (6.1-10.8 mg) and Ca (350-370 mg). When I-FM was fed, the RDA was met for each nutrient except Ca (370-490 mg) at all ages and Fe (13.1 mg) at 11-12 months. Estimated safe and adequate daily intake of Na was exceeded at 9-10 months by infants fed WCM/2% and at 11-12 months by all infants regardless of milk feeding, primarily because of the high Na content of solid foods. These data confirm that the milk feeding is still the major determinant of total nutrient intake in the second 6 months of life.     

Update on NHANES Dietary Data: Focus on Collection,Release, Analytical Considerations,and Uses to Inform Public Policy

NHANES is the cornerstone for national nutrition monitoring to inform nutrition and health policy. Nutritional assessment in NHANES is described with a focus on dietary data collection, analysis, and uses in nutrition monitoring. NHANES has been collecting thorough data on diet, nutritional status, and chronic disease in cross-sectional surveys with nationally representative samples since the early 1970s. Continuous data collection began in 1999 with public data release in 2-y cycles on ∼10,000 participants. In 2002, the Continuing Survey of Food Intakes by Individuals and the NHANES dietary component were merged, forming a consolidated dietary data collection known as What We Eat in America; since then, 24-h recalls have been collected on 2 d using the USDA’s Automated Multiple-Pass Method. Detailed and targeted food-frequency questionnaires have been collected in some NHANES cycles. Dietary supplement use data have been collected (in detail since 2007) so that total nutrient intakes can be described for the population. The continuous NHANES can adapt its content to address emerging public health needs and reflect federal priorities. Changes in data collection methods are made after expert input and validation/crossover studies. NHANES dietary data are used to describe intake of foods, nutrients, food groups, and dietary patterns by the US population and large sociodemographic groups to plan and evaluate nutrition programs and policies. Usual dietary intake distributions can be estimated after adjusting for day-to-day variation. NHANES remains open and flexible to incorporate improvements while maintaining data quality and providing timely data to track the nation’s nutrition and health status. In summary, NHANES collects dietary data in the context of its broad, multipurpose goals; the strengths and limitations of these data are also discussed in this review.     

Estimated nutrient intakes and adequacies in Bangladesh change when newer values for vitamin A,iron and calcium in commonly consumed foods are applied

A food consumption survey was conducted in rural Bangladesh in January–March 1996 using a 24-h food weighing method. Intakes and adequacies of energy, vitamin A, vitamin C, iron and calcium were estimated for 81 children (aged 24–71 months) and 182 women (aged 18–45 years) using three sets of food composition tables. The local food composition table was modified with newer values for nutrient contents of foods identified as important for the contribution of vitamin A and iron. Significant differences in estimated dietary intakes and adequacies were found for vitamin A and iron when different sets of food composition values were used. This study shows that up-to-date chemical analyses of foods selected on the basis of a high frequency of consumption and a large contribution of the nutrients in focus is a useful approach in improving the quality of food composition tables, resulting in greater accuracy of estimates of nutrient intakes and adequacies.     

Nutritional status of U.S. elite female heptathletes during training

This study describes the body composition, dietary nutrient intake, dietary practices, and biochemical indices of iron status of elite female American heptathletes during training. Four-day diet records and dietary practice questionnaires were obtained from 19 female heptathletes (26 +/- 3 years) during the training season. Anthropometric measurements and fasting blood samples were obtained at the lowest phase of the training cycle. These athletes had a low body fat (13.8 +/- 2.7%) and high fat-free mass to height ratios (33.0 +/- 2.0 kg/m). Average nutrient intakes were > 67% of the reference intakes for all nutrients except vitamin E. Most dietary nutrient densities were higher than NHANES III nutrient densities for women 20-29 years old. More than 50% of the athletes took vitamin supplements and monitored their hydration status. Fifteen of the 17 athletes reported a normal menstrual cycle. Markers of biochemical iron status were all within the normal range. On average, these athletes were lean with high levels of fat free mass, adequate nutrient intakes, and normal biochemical indices of iron status. However, individual data reveals considerable variability within this group.     

Estimation of conjugated linoleic acid intake by written dietary assessment methodologies underestimates actual intake evaluated by food duplicate methodology

Conjugated linoleic acids (CLA) are conjugated isomers of linoleic acid, which may promote health with regard to cancer, heart disease, diabetes, bone formation, growth modulation and immunity. The c9,t11 isomer of CLA, rumenic acid (RA), is the major isomer present in the diet. However, dietary intakes of CLA and RA by humans have not been examined rigorously, nor has the relationship between dietary CLA or RA and health (e.g., body composition). Three-day dietary records (DR) were collected from adult men (n = 46) and women (n = 47) and analyzed using a nutrient database modified to contain total CLA and RA. Simultaneously, 3-d food duplicates (FD) were collected to determine analytically individual fatty acid intakes, including those of total CLA and RA. Chronic total CLA and RA intakes were estimated using a semiquantitative food-frequency questionnaire (FFQ). Body composition was estimated using body mass index and percentage of body fat. Total CLA intake was estimated from FD to be 212 +/- 14 and 151 +/- 14 mg/d (mean +/- SEM) for men and women, respectively; RA intake was estimated to be 193 +/- 13 and 140 +/- 14 mg/d for men and women, respectively. In general, CLA and RA intakes estimated by DR and FFQ were significantly lower than those estimated by FD. Body composition was not significantly related to dietary total CLA or RA intake. In conclusion, results suggest that DR and FFQ methodologies are not reliable estimators of individual total CLA and RA intakes and may underestimate total CLA and RA intakes of groups. Intake of total CLA and RA was found to be significantly lower than that suggested previously by others.     

Collection of food and dietary supplement intake data: What We Eat in America-NHANES

This paper describes the collection process for the integrated dietary component of the National Health and Nutrition Examination Survey(NHANES) 2002 (entitled What We Eat in America-NHANES), referred to here as the integrated survey. The dietary components of previous NHANES cycles and the Continuing Survey of Food Intake in Individuals (CSFII) are also described. The collection process for foods in the integrated survey consists of an in-person 24-h recall using a computerized 5-step method and a second nonconsecutive 24-h recall via telephone. A food frequency questionnaire is being pilot-tested to provide information on the propensity to consume certain foods. Dietary supplement intakes over the past 30 d are assessed for all persons during the household interview. Other diet-related data are also obtained. Strengths of the integrated survey include information on food and supplement intakes in a representative sample of the civilian noninstitutionalized population of the United States that can be linked to anthropometric, biochemical, clinical and disease history information in NHANES. After reviewing the current state of the art on dietary and dietary supplement data collection, discussion groups consisting of members of key stakeholder community concluded that, although the most advanced methods for dietary data collection available are being used, the differences between how information on food and dietary supplement intakes is collected make it challenging to combine data describing nutrients from both sources to obtain estimates of total nutrient intakes. The discussion groups concluded that more research is needed on these issues and provided key recommendations for future efforts in this important area of public health surveillance.     

Dietary Intake and Representativeness of a Diverse College-Attending Population Compared with an Age-Matched US Population

Young adults typically gain more dietary autonomy as they start college, though this can also present nutritional challenges; however, research on the generalizability of their dietary intake data is scarce. To address this representativeness concern, we compared food and nutrient intakes reported by college freshmen attending a large, diverse university to an age-matched sample from the National Health and Nutrition Examination Survey (NHANES). We studied 269 students 18–24 years old recruited through the Mason: Health Start Here (HSH) study, a population-based cohort study of college students. Diet was assessed using a diet history questionnaire (DHQ-III) and estimated with food source composition tables. The NHANES sample of 835 adults was the reference dataset. Reported dietary intakes were weighted and compared with national intakes via t-tests. We observed comparable energy, carbohydrate, fat, and protein intakes in both groups; however, the HSH cohort reported a higher density intake of most micronutrients than the NHANES sample. Differences between these samples in intake, mode of dietary assessment administration, and reactivity may help explain the differences detected. These results demonstrate that when appropriately contextualized in terms of methodology and potential sources of bias, single college studies can be useful for understanding nutrition in young adults more broadly.     

A comparative study of two nutrient data bases

Reported dietary intake records of 18 infants, 22 young children, and 20 women were analyzed using the nutrient data base systems of the Second National Health and Nutrition Examination Survey (NHANES II) and the Nutrient Dietary Data Analysis (NDDA) System. Significant differences between the nutrient data bases were found in the calculations of potassium and niacin for infants and of energy and nine nutrients for women and children. The energy and nutrient composition of many commonly consumed food items in the two nutrient data base systems was different, even though the systems shared common data sources. Differences in the nutrient data bases were primarily due to the timing of data base updates, as well as to the differential use of industry, private, and government food analysis sources, procedural differences in data base updating, and random data entry error. Resolution of differences among nutrient data base systems may depend upon comprehensive reviews of all data base systems or the establishment of a national nutrient data base to serve as a standard for the professional.     

Dietary exposure and trends of exposure to nutrient elements iodine, iron, selenium and sodium from the 2003-4 New Zealand Total Diet Survey

The mean dietary exposure to the nutrient elements iodine, Fe, Se and Na by eight age-sex groups of the New Zealand population was estimated from foods purchased and prepared as for consumption. A total of 968 samples comprising 121 foods were collected and analysed. Mean daily exposures were calculated from mean concentration levels of the selected nutrients in each food combined with simulated diets for a 25+-year-old male and female, a 19-24-year-old male, a 11-14-year-old boy and girl, a 5-6-year-old child, a 1-3-year-old toddler and a 6-12-month-old infant. Food concentrations and dietary exposures are reported and compared with nutrient reference values (for example, recommended daily intakes, adequate intakes or upper limits). Dietary iodine exposures for all age-sex groups were well below recommended levels and have steadily decreased since 1982, raising concern especially for the physical and mental development of infants and young children. Fe exposures meet the recommended daily intake for the average male and 11-14 year olds but are only about half that recommended for adult females. Se exposure is about 20 % less than optimal for females. Na exposures, excluding discretionary salt, are above the acceptable exposure level for all age-sex groups, and exceed the upper intake limits for 25+-year-old males, 19-24-year-old young males, and 11-14-year-old boys and girls by up to 125 % for an average consumer.     

Trace element intakes of women

1. Energy, protein, zinc, copper, manganese, selenium and dietary fibre intakes of 100 pre-menopausal women (mean age 30.0 +/- 6.1 years) from a university community, and consuming self-selected diets, were calculated using 3 d dietary records and food composition values. Subjects also collected a 24 h food composite during the 3 d record period for analysis of Zn, Cu and Mn by atomic absorption spectrophotometry. Daily analysed intakes were compared with those calculated from the corresponding record day. 2. Mean daily calculated intakes of energy, protein, Zn, Cu, Mn, Se and dietary fibre were 7.54 +/- 1.61 MJ, 74 +/- 18 g protein, 10.1 +/- 3.3 mg Zn, 1.9 +/- 0.6 mg Cu, 3.1 +/- 1.5 mg Mn, 131 +/- 53 micrograms Se, 19.4 +/- 6.6 g dietary fibre. 3. Major food sources for each of the trace elements were (%): Zn meat + substitutes 43, dairy products 23.7; Cu breads and cereals 22, vegetables 21; Mn breads and cereals 47, fruits 12, Se meat + substitutes 38, breads and cereals 30. 4. Highly significant correlations (P = 0.001) were noted for analysed intakes of Zn, Cu and Mn and those calculated from the corresponding record day. Mean calculated intakes were higher (%): Zn 138, Cu 142, Mn 121, than corresponding mean analysed intakes (P = 0.01). However, the mean nutrient densities (mg/MJ) were comparable: Zn analysed 1.2, calculated 1.4; Cu analysed 0.2, calculated 0.2; Mn analysed 0.4, calculated 0.4. 5. All subjects met the Canadian Dietary Standard (CDS) recommended level for Cu but 48% received less than the CDS for Zn, 6% obtaining less than two-thirds of this recommended level. Daily Mn and Se intakes were similar to recent values for North American diets.     

Food components and dietary patterns of two different groups of Mexican lactating women

OBJECTIVE: To evaluate the energy, nutrient intakes and dietary patterns of Mexican lactating women at one month postpartum, and the associations of maternal age and region on their intakes. METHODS: A total of 60 women were studied: 41 from Northwest and 19 from Central Mexico, 33 adolescent and 27 adult women. Data were collected through two quantitative 24 h recalls. Two more recalls were used in a sub sample to calculate the coefficient of variation of intakes. Menus were based on the consumption frequency of foods. RESULTS: The mean energy intake of the adolescent women (2354 +/- 1199 kcal) and those of Central Mexico (1690 +/- 981 kcal) was lower than the recommendations. Zinc, calcium, vitamin E, C and folate were inadequate (55 to 85% prevalence of inadequacy). Energy, dietary fiber, sodium, potassium, iron and folate intakes were higher (P < 0.05) in Northwest Mexico. Northwestern women consumed less variety of vegetables or fruits compared to Mexico City region women. Wheat tortillas and beans were from Northwestern but not from the Mexico City region diet. CONCLUSIONS: The energy and nutrient intakes of women were different by regional hospital and not by age. Education about the importance of the maternal diet during lactation should be directed toward increasing consumption of foods rich in micronutrients.     

A data-based approach to diet questionnaire design and testing

A self-administered diet history questionnaire has been developed for epidemiologic and clinical use. Both the food list and the nutrient values to be associated with it were developed using dietary data from 11,658 adult respondents to the Second National Health and Nutrition Examination Survey (NHANES II). Food items were selected on the basis of their contribution to total population intake of energy and each of 17 nutrients in the NHANES II data, and represent over 90% of each of those nutrients. Associated nutrient composition values were determined from the NHANES II database using frequency of consumption data in that survey. Portion sizes to be associated with each food item were derived from observed portion size distributions in NHANES II, based on three-dimensional models. The resulting food list and its corresponding brief data base, when used to calculate nutrients from a diet record, yielded correlations of r greater than 0.70 with the more detailed method. Field administration produced mean values comparable to national data.     

Multivitamin-multimineral supplements: who uses them?

Dietary supplement use is increasingly common in the United States. Multivitamin formulations with or without minerals are typically the most common type of dietary supplement reported in surveys and studies that collect data relating to dietary supplement use. In the National Health and Nutrition Examination Survey (NHANES) 1999-2000, 52% of adults reported taking a dietary supplement in the past month, and 35% reported regular use of a multivitamin-multimineral (MVMM) product. NHANES III data indicate an overall prevalence of dietary supplement usage of 40%, with prevalence rates of 35% in NHANES II and 23% in NHANES I. Women (versus men), older age groups, non-Hispanic whites (versus non-Hispanic blacks or Mexican Americans), and those with a higher education level, lower body mass index, higher physical activity level, and more frequent consumption of wine had a greater likelihood of reporting use of MVMM supplements in NHANES 1999-2000. Data from children suggest a similar prevalence rate, but lower prevalence rates of usage were reported in studies of adolescents. Individuals who use dietary supplements (including MVMM formulations) generally report higher dietary nutrient intakes and healthier diets in studies in which dietary data were also collected. Among adults with a history of breast or prostate cancer, usage rates for dietary supplements in general and MVMMs are considerably higher (eg, 56-57% for MVMMs), and these subgroups are more likely to also report use of single vitamin and mineral supplements. Thus, MVMM use contributes a considerable proportion of nutrient intakes in the United States and may contribute to risk of excessive intakes.     

Dietary intakes of nutrients thought to modify cardiovascular risk from three groups of American Indians: The Strong Heart Dietary Study, Phase II

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of mortality among American Indians. Rates of CVD appear to be increasing among American Indians while they are decreasing among other racial and ethnic groups in the United States. Rates of comorbid conditions associated with CVD, such as obesity, impaired glucose tolerance, and hypertension, are also higher among American Indians than among other racial and ethnic groups in the United States. Dietary factors play a role in the development of CVD and associated comorbid conditions, yet surprisingly few data exist to describe the dietary intakes and nutritional adequacy of American Indian adults at risk for CVD. OBJECTIVE: To describe intakes of nutrients that may affect CVD risk consumed by members of 13 nations of American Indian adults, aged 45 to 70 years, who reside in tribal communities in Arizona, North Dakota, South Dakota, and Oklahoma. A secondary objective was to compare dietary intake estimates to nationally representative data from adults of similar age to determine potential dietary differences that may account for the disparities seen in rates of CVD and related conditions. Finally, dietary intake estimates were compared with national dietary guidance to determine areas for improvement. METHODS: Data from a 24-hour dietary recall provided by 3,482 adults who participated in the Strong Heart Dietary Study, Phase II, were analyzed to describe dietary intakes of nutrients that may alter CVD risk. Nonparametric analyses of variance were used to compare data by center, age, and sex. Dietary intake data for each sex/center group were compared with data from the Third National Health and Nutrition Examination Survey (NHANES III), Phase I, dietary estimates, and to national dietary guidelines. RESULTS: Nutrient intakes varied little between centers. Sex differences were noted in energy and nutrient intakes across all centers. Age-related decreases in energy and total and saturated fat intakes were noted among all sex/center groups. Median intakes of vitamins A and C and folate were low among all sex/center groups. Remarkably few differences in dietary intake were noted between NHANES III and Strong Heart Dietary Study, Phase II, participants. Carbohydrate and sodium intakes were higher among participants compared with NHANES III estimates, whereas intakes of several vitamins were lower. CONCLUSIONS: Dietary intakes of American Indians vary by age, sex, and geographic location, but do not differ substantially from national estimates of dietary intake. The dietary differences noted between NHANES III and Strong Heart Dietary Study, Phase II, participants are not consistent with the remarkably different rates of CVD and associated comorbidities that currently exist.     

The Dietary Variety Score: Assessing Diet Quality in Healthy Young and Older Adults

Objective To develop a new dietary variety score (DVS) and link it to other measures of diet quality, including a modified diet quality index (DQI).Subjects The subjects were 24 healthy young (ages 20 to 30 years) and 24 healthy older (ages 60 to 75 years) adults, including 24 men and 24 women. Their dietary intake assessments were based on one 24-hour food recall interview and 14 consecutive days of food records.Design and measures Energy and nutrient intakes were estimated using Nutritionist IV software. DVS was based on the cumulative number of different foods consumed over the 15-day period. DQI was a 5-potnt scale based on conformity with the key US dietary recommendations. Full score was awarded for diets deriving 30% or less of energy from fat, 10% or less of energy from saturated fat, more than 50% of energy from carbohydrate, and containing less than 300 mg cholesterol and 2,400 mg sodium per day. Analytic measures included analyses of variance, correlation analyses, and χ² tests.Results Older subjects consumed more varied diets than did young subjects. Higher DVS values were linked positively to vitamin C intakes and negatively to the consumption of salt, sugar, and saturated fat. However, a high DVS was not linked to a high score on the DQI in this subject sample. Discussion/conclusions Few studies have addressed the issue of how many different foods constitute a varied diet. The present classification scheme offers a new way of assessing dietary variety at the individual or group level. Measures of dietary variety may represent an additional facet of diet quality and their relationship to selected health outcomes should be examined further. J Am Diet Assoc. 1997;97:266–271.