The objective of the dietary interview component is to obtain detailed dietary intake information from NHANES participants. The dietary intake data are used to estimate the types and amounts of foods and beverages (including all types of water) consumed during the 24-hour period prior to the interview (midnight to midnight), and to estimate intakes of energy, nutrients, and other food components from those foods and beverages. Following the dietary recall, participants are asked questions on salt use, whether the person’s overall intake on the previous day was much more than usual, usual or much less than usual, and whether the respondent is on any type of special diet. Questions on frequency of fish and shellfish consumed during the past 30 days were asked of survey participants 1 year or older, with the use of proxies for young children (see the MEC In-Person Dietary Interviewers Procedures Manual for more information on the proxy interview).
The dietary interview component, called What We Eat in America (WWEIA), is conducted as a partnership between the U.S. Department of Agriculture (USDA) and the U.S. Department of Health and Human Services (DHHS). Under this partnership, DHHS' National Center for Health Statistics (NCHS) is responsible for the survey sample design and all aspects of data collection and USDA’s Food Surveys Research Group (FSRG) is responsible for the dietary data collection methodology, maintenance of the databases used to code and process the data, and data review and processing.
All NHANES participant are eligible for two 24-hour dietary recall interviews. The first dietary recall interview is collected in-person in the Mobile Examination Center (MEC) and the second interview is collected by telephone 3 to 10 days later.
As in previous years, two types of dietary intake data are available for the 2011-2012 survey cycle: Individual Foods files and Total Nutrient Intakes files.
What's New with the 2011-2012 WWEIA Release:
In the Individual Foods files, the range of response options regarding the source from which each food/beverage was obtained (e.g., from a store, fast food restaurant, cafeteria, etc.) has been expanded. The former “store” code has been divided into three separate codes to specify whether the source was a grocery store/supermarket, a convenience store, or store—no additional information.
Appendix 1 provides a summary of changes among the 5 latest cycles of data collection.
New additions for analyzing WWEIA data include:
Expanded documentation on Combination codes.
The What We Eat in America Food Categories, available on the FSRG website (www.ars.usda.gov/ba/bhnrc/fsrg), are a new grouping scheme that combines foods and beverages together that have similar usage and nutrient content with the emphasis on how they are commonly consumed in the American diet. There are approximately 150 unique categories and each is assigned a 4-digit number and description. The WWEIA Food Categories contain discrete food items and are not disaggregated (e.g., pizza vs. grain, cheese, tomatoes, etc.). Designed to be flexible, the categories can be combined as needed to address specific research questions. A new version of the WWEIA Food Categories is produced for each 2-year release cycle of WWEIA, NHANES.
Distinguishing Between Foods/Beverages and Dietary Supplements in NHANES
The 24-hour dietary supplement use component is administered after the 24-hour dietary recall. All NHANES participants responding to the 24-hour dietary recall interview are eligible for the dietary supplement and non-prescription antacid use questions. Information is obtained on all vitamins, minerals, herbals, and other dietary supplements as well as non-prescription antacids that were consumed during a 24-hour time period (midnight to midnight), including the name and the amount of supplement or antacid taken.
Distinguishing between foods/beverages and supplements can be challenging. NCHS and FSRG review questionable items reported in the dietary supplement and dietary recall components to resolve disposition of these items into the appropriate component. Products that are labeled as a dietary supplement, that have a supplement facts panel on the label, and are in tablets, capsules, softgels, gelcaps, or other pill forms, are considered dietary supplements. Items that are powders or liquids can be hard to distinguish. General guidelines used state that if powders and liquid concentrates have product directions stating that they be added to a liquid, they are classified as beverages. Examples are teas and protein powders. An exception is made for fiber products, which are classified as dietary supplements. Along this same guideline, energy drinks are considered beverages, but “energy shot” type products are considered dietary supplements.
It is best to refer to the two databases that detail every food/beverage and dietary supplement reported in NHANES to identify exact determination used. The databases are:
Dietary Interview Data Files: Four data files were produced from the information collected in the dietary interviews: two Individual Foods files and two Total Nutrient Intakes files. Each file includes one day of intake data. The number “1” or “2” in the file name identifies the day (and mode) of the interview: 1 = first day (in-person), 2 = second day (phone). File names are as follows:
| File | Day 1 | Day 2 |
|---|---|---|
| Individual Foods File | DR1IFF_G | DR2IFF_G |
| Total Nutrient Intakes File | DR1TOT_G | DR2TOT_G |
The amounts in these files reflect only nutrients obtained from foods, beverages, and water including tap and bottled water. They do not include nutrients obtained from dietary supplement intakes, antacids, or medications. Data on intakes of dietary supplement use are available on the NHANES 2011-2012 Dietary Data page.
Individual Foods Files (DR1IFF_G and DR2IFF_G): Detailed information about each food/beverage item (including the description, amount of, and nutrient content) reported by each participant is included in the Individual Foods files. The names for both Day 1 and Day 2 variables are listed in Appendix 2.
The Individual Foods files include, for each interview day, one record for each food/beverage consumed by a survey participant. Each record is uniquely numbered within a person’s set of records and contains the information listed below:
The Individual Foods files include, for each interview day, one record for each food consumed by a survey participant. Each food record is sequentially numbered and contains the information listed below:
Descriptions for the USDA FNDDS food codes and modification codes are provided in two files: the Food Code Description file (DRXFCD_G) and the Modification Code Description file (DRXMCD_G). The DRXFCD_G file includes abbreviated descriptions (up to 80 characters) and complete descriptions (up to 200 characters) associated with each USDA food code in the FNDDS 2011-2012. The DRXMCD_G file includes descriptions (up to 240 characters) associated with each modification code identified in the Individual Foods files. Modification codes represent adjustments to predefined recipe ingredients that reflect more closely the food as described by the participant. Appendix 4 provides SAS code examples that may be used to link the food code or the modification code description to the Individual Foods file.
Total Nutrient Intakes Files (DR1TOT_G and DR2TOT_G): For each participant, daily total energy and nutrient intakes from foods and beverages, and whether the amount of food consumed was usual, much more than usual, or much less than usual, are included in the Total Nutrient Intakes files. The Day 1 file also includes information on salt use in cooking and at the table; whether the participant is currently on any kind of diet to lose weight or for another health-related reason and, if so, the type of diet; and information on frequency of fish and shellfish consumption for participants aged 1 or older. The names for both Day 1 and Day 2 variables are listed in Appendix 5.
The Total Nutrient Intakes files provide a summary record of total nutrient intakes for each individual. Each total intake record contains the following information:
All NHANES participants are eligible for the dietary interview component. However, only participants one year or older are eligible for the frequency of fish and shellfish consumption questions following the 24-hour recall.
The examination protocol and data collection methods are fully documented in the NHANES dietary interviewer procedures manuals (In-person interview: https://wwwn.cdc.gov/nchs/data/nhanes/2011-2012/manuals/mec_in_person_dietary_procedures_manual_jan_2012.pdf
phone follow-up interview: https://wwwn.cdc.gov/nchs/data/nhanes/2011-2012/manuals/phone_follow-up_dietary_procedures.pdf).
Interviews were conducted for survey participants less than six years of age with a proxy (who was generally the person most knowledgeable about the survey participant’s intake). Interviews of children ages 6 to 8, were conducted with a proxy and with the child present to assist in reporting intake information. Interviews of children ages 9-11, were conducted with the child and the assistance of an adult familiar with the child’s intake. Participants 12 years or older answered for themselves. Dietary interviewers conducted interviews in English and Spanish. Translators were used to conduct interviews in other languages.
The in-person interview was conducted in a private room in the NHANES mobile examination center (MEC). A set of measuring guides (various glasses, bowls, mugs, drink boxes and bottles, household spoons, measuring cups and spoons, a ruler, thickness sticks, bean bags, and circles) was available in the MEC dietary interview room for the participant to use for reporting amounts of foods (NHANES Measuring Guides for the Dietary Recall Interview: https://www.cdc.gov/nchs/nhanes/measuring_guides_dri/measuringguides.htm). Upon completion of the in-person interview, participants were given measuring cups, spoons, a ruler, and a food model booklet, which contained two-dimensional drawings of the various measuring guides available in the MEC, to use for reporting food amounts during the telephone interview. Telephone dietary interviews were collected 3 to 10 days following the MEC dietary interview, but not on the same day of the week as the MEC interview. Any participant who did not have a telephone was given a toll-free number to call so that the recall could be conducted.
What We Eat in America data were collected using USDA's dietary data collection instrument, the Automated Multiple Pass Method (AMPM) (http://www.ars.usda.gov/ba/bhnrc/fsrg). The AMPM was designed to provide an efficient and accurate means of collecting intakes for large-scale national surveys. The AMPM is a fully computerized recall method that uses a 5-step interview outlined below:
The AMPM includes an extensive compilation of standardized food-specific questions and possible response options. Routing of questions is based on previous responses. The AMPM is updated for each 2-year collection of WWEIA to reflect the changing food supply and to address research needs from the data user community. Additional information about the AMPM is provided in Raper et al. (Raper et al., 2004).
The AMPM was validated in a large study and shown to be an effective method for collecting accurate group energy intake of adults. Completed in 2004, this extensive research project included 524 healthy, weight-stable volunteers, aged 30-69 years. The accuracy of the AMPM was evaluated by comparing reported energy intake (EI) to total energy expenditure (TEE) using the doubly labeled water technique (Moshfegh et al., 2008). Among the findings were that EI compared to TEE was under-reported by 11% overall, by less than 3% for normal weight subjects with body mass index (BMI) < 25 and 16% for overweight subjects with BMI ≥ 25.
Additional studies provide evidence that the AMPM accurately measures group energy intake. Blanton (Blanton et al., 2006) reported that EI was not significantly different from TEE for a sample of 20 adult females. Rumpler and colleagues found that mean EIs were accurately reported for a sample of 12 adult males (Rumpler et al., 2008).
Additional evidence for the accuracy of AMPM has been provided by analysis of the 24-hour urinary sodium data collected in the AMPM Validation Study, which suggest the AMPM is a valid measure for estimating sodium intake in adults. Dietary sodium intake calculated from 24-hour recall data of 465 subjects collected via AMPM was compared with sodium values from 24-hour urine collections measured during the same 24-hour period. The AMPM-derived mean dietary sodium estimates reflected over 90% of the biomarker-based estimates (Rhodes et al., 2013).
For additional information about the dietary interview component and related survey protocols, please go to the Survey Operations Manuals, Brochures, Consent Documents site at: https://wwwn.cdc.gov/nchs/nhanes/continuousnhanes/default.aspx?BeginYear=2011.
All dietary interviewers were required to complete an intensive one-week training course and to conduct supervised practice interviews before working independently in the field. Retraining sessions were conducted annually to reinforce the proper protocols and technique.
Interviewers were monitored throughout the data collection period. Monitoring consisted of the following:
Interview data files were sent electronically from the field and were imported into Survey Net, a computer-assisted food coding and data management system developed by USDA (Raper et al., 2004).
USDA's Food and Nutrient Database for Dietary Studies (FNDDS) 2011-2012 was used for processing the 2011-2012 intakes (http://www.ars.usda.gov/ba/bhnrc/fsrg). The FNDDS includes comprehensive information that can be used to code individual foods and portion sizes reported by participants and also includes nutrient values for calculating nutrient intakes. The underlying nutrient values for FNDDS 2011-2012 were based on values in the USDA National Nutrient Database for Standard Reference, release 26, produced by USDA’s Nutrient Data Lab (http://www.ars.usda.gov/nutrientdata). FNDDS values are updated for every 2-year WWEIA, NHANES release cycle.
FNDDS 2011-2012, which corresponds with WWEIA 2011-2012, now includes the addition of enhanced characterization of food and beverages indicating if the item is fortified or contains fortified ingredients. Another enhancement for FNDDS 2011-2012 is the incorporation of the Recipe Protocol Project, which provides a framework for the selection of ingredients and amounts across similar foods. The protocols standardize and modernize new and existing recipes for about 2,500 items in FNDDS 2011-2012. Additional information about the FNDDS and related tools is available on the Food Surveys Research Group website (Raper et al., 2004; Anand et al., 2006; Ahuja et al., 2008).
Coders were required to pass a certification test after the initial training. They were routinely monitored to ensure the quality and completeness of their work. Approximately 10 percent of the coder's work was randomly selected to be independently coded by another coder. Results from the two codings were compared and adjudicated, if necessary.
After intake data were coded, various types of reviews were conducted to ensure the quality of the data. An overview of quality assurance procedures conducted during the data processing stage is available in Anand, et al. (Anand et al., 2006). Examples of reviews include the following:
During data processing, the following edit was made to ensure the logical consistency and analytic usefulness of the data:
A data processing step called salt adjustment that was based on survey participants' responses to selected questions was discontinued in 2009-2010 (Sebastian et al. 2013; Sebastian et al. 2012). For participants whose households used salt in cooking occasionally or less often, some or all of the salt attributable to home preparation was removed from foods that typically have salt added during preparation and were obtained from the store.
Factors leading to the discontinuation of the data processing step of salt adjustment, include the following:
For more detail about the data processing step of salt adjustment and its discontinuation, see Sebastian et. al. (Sebastian et al. 2013; Sebastian et al. 2012).
Each Individual Foods file (Day 1 and Day 2) is comprised of food records. For most survey participants, there are multiple records in each file. For each Total Nutrient Intakes file (Day 1 and Day 2) there is one record for each participant. These files can be linked with other NHANES files by the respondent sequence number (SEQN).
Variable names: For data collected on both Day 1 and Day 2, variable names are differentiated by having the number "1" or "2" in the third position of the variable name to identify the collection day. For example, the USDA food code variable (in the Individual Foods File), which identifies the food reported by the participant, is named DR1IFDCD in the Day 1 file and DR2IFDCD in the Day 2 file. Appendices 2 and 5 list the Day 1 and Day 2 variable names for the Individual Foods file and the Total Nutrient Intakes file, respectively.
Names for the following variables are the same for both days in the Individual Foods file and the Total Nutrient Intakes file:
| Day 1 and Day 2 variable name | Label |
|---|---|
| SEQN | Respondent sequence number |
| WTDRD1 | Dietary day one sample weight |
| WTDR2D | Dietary two-day sample weight |
| DRABF | Breast-fed infant (either day) |
| DRDINT | Number of days of intake |
Number of days of intake: A variable has been included to indicate the number of days of intake collected from each participant. The variable name is DRDINT. In 2011-2012, 8,519 participants provided complete dietary intakes for Day 1. Of those providing the Day 1 data, 7,605 provided complete dietary intakes for Day 2.
Dietary recall status code: A status code (DR1DRSTZ or DR2DRSTZ) is used in both the Individual Foods and Total Nutrient Intakes files to indicate the quality and completeness of a survey participant's response to the dietary recall section. The codes are the following:
1 = Reliable and met the minimum criteria
For individuals with a code 1, all relevant variables associated with the 24-hour dietary recall contain a value.
2 = Not reliable or did not meet the minimum criteria
Individuals with a code 2 have incomplete records. No data on total nutrient intakes and the total number of foods reported are provided for these cases. These individuals have no records in the Individual Foods files.
3 [Code 3 is not included in the current datasets. It was only used for data from the 1999-2000 survey cycle.]
4 = Reported consuming breast milk
For infants and children who consumed human milk, there is a record in the Individual Foods files for each report of human milk. However, because amounts of human milk intake are not quantified, these records contain missing values for the amount consumed and for the amounts of energy and nutrients from human milk. Also, records of human milk have a missing value for the food source variable (DR1FS, DR2FS) and the eaten at home variable (DR1_040Z, DR2_040Z) in the Individual Foods files. Records for any other foods and beverages consumed by breast-fed infants and children are included in the Individual Foods files along with their amounts and nutrient information. Because of the missing amount or quantity information for human milk, no total nutrient intakes (contained in the Total Nutrient Intakes files) were computed for participants with a code 4.
A variable that identifies breast-fed children, DRABF, is included. This variable has a code of 1 if a child consumed human milk in either intake day.
5 = Not done
This code is assigned when the dietary recall section of the interview did not take place due to various reasons (such as arrived late/left early, refusal, illness, emergency, or equipment failure). These individuals have no records in the Individual Foods files. These individuals have a record in the Total Nutrients file with values only for the following variables: the respondent sequence number (SEQN), the dietary recall status code (DR1DRSTZ or DR2DRSTZ) and for participants one year or older, the fish and shellfish questions in the DR1TOT_G file (DRD340, DRD350A-K, DRD350AQ-JQ, DRD360, DRD370A-V, and DRD370AQ-UQ).
Although there are four possible values, only codes 1 and 4 appear in the Individual Foods file. In addition to the status code described above, the variable DR1_300 and DR2_300 in the Total Nutrients file, denotes the participant's assessment of whether the amount of food consumed on the recall day was usual, much more than usual, or much less than usual.
Participants who reported consuming only water, no food or other beverages: Records are included in the Individual Foods file for participants who consumed only water. There are 7 such individuals in the 2011-2012 datasets, 1 in the Day 1 data and 6 in the Day 2 data. Their dietary recall status variable for the day is coded as "1" (complete and reliable) in the Total Nutrients file and the total number of items is coded based on how many times water was reported. Individuals with just water intake and no food intake will have zero energy intake for the day.
Participants who reported consuming no water, food or other beverages: There can be survey participants whose intakes are determined to be complete even though they reported no water, food, or other beverage records for the day. For such participants there are no records in the Individual Foods file but their dietary recall status is coded as complete and reliable and the Total Nutrients file will include records with zero values for all nutrients. In the 2011-2012 datasets, there are no such participants.
Number of days between the intake day and the day of family interview: Each of the four intake files includes a variable (DR1DBIH for Day 1 files and DR2DBIH for Day 2 files) to indicate the number of days between the intake day (i.e., the period covered by the 24-hour recall) and the day that the family questionnaire was administered in the household. A positive value in DR1BHIH or DR2BHIH indicates the family interview occurred prior to the intake day. In the survey, most of the family interviews were done before the participant came to the MEC and participated in the dietary interview. A value of "0" in DR1BHIH or DR2BHIH indicates the family interview occurred on the same date as the intake day. A negative value (i.e., DR1BHIH<0 or DR2BHIH<0) means that the family interview occurred after the intake day.
Food source: The source from which each food was obtained (e.g., from a store, fast food restaurant, cafeteria) is identified by the variables DR1FS (day 1) and DR2FS (day 2) in the Individual Foods files.
In 2011-2012, the code for “store” (value=1) has been divided into three separate codes: “Store - grocery/supermarket” (value=1), “Store - convenience type” (value=27), and “Store - no additional info” (value=28). Additionally, descriptions “Cafeteria not at school” and “Cafeteria at school” have been revised to “Cafeteria NOT in a K-12 school” and “Cafeteria in a K-12 school.”
The code descriptions for this variable are:
| Code | Description |
|---|---|
| 1 | Store grocery/supermarket |
| 2 | Restaurant with waiter/waitress |
| 3 | Restaurant fast food/Pizza |
| 4 | Bar/Tavern/Lounge |
| 5 | Restaurant, no additional information |
| 6 | Cafeteria NOT in a K-12 school |
| 7 | Cafeteria in a K-12 school |
| 8 | Child care center |
| 9 | Family/Adult day care center |
| 10 | Soup kitchen/shelter/food pantry facility |
| 11 | Meals on Wheels Program |
| 12 | Community food program – other |
| 13 | Community program, no additional info |
| 14 | Vending machine |
| 15 | Common coffee pot or snack tray |
| 16 | From someone else/gift |
| 17 | Mail order purchase |
| 18 | Residential dining facility |
| 19 | Grown or caught by you or someone you know |
| 20 | Fish caught by you or someone you know |
| 24 | Sport, recreation, or entertainment |
| 25 | Street vendor, vending truck |
| 26 | Fundraiser sales |
| 27 | Store - convenience type |
| 28 | Store - no additional information |
| 91 | Other, specify |
Eating occasion: The variables DR1_030Z and DR2_030Z are located in the Individual Foods file. The code descriptions for the eating occasion variables are shown in the table below.
| Code | Description |
|---|---|
| 1 | Breakfast |
| 2 | Lunch |
| 3 | Dinner |
| 4 | Supper |
| 5 | Brunch |
| 6 | Snack |
| 7 | Beverage/Drink |
| 8 | Feeding-infant only |
| 9 | Extended consumption |
| 10 | Desayuno |
| 11 | Almuerzo |
| 12 | Comida |
| 13 | Merienda |
| 14 | Cena |
| 15 | Entre comida |
| 16 | Botana |
| 17 | Bocadillo |
| 18 | Tentempie |
| 19 | Bebida |
| 91 | Other |
Eating occasion was designated by the respondent. During the interview, a list of eating occasion names was available to the respondent for selection. However, eating occasion names were not defined for the respondent and the interpretation may differ from one person to another.
Foods and beverages coded as part of a combination: Forty-three percent of foods and beverages reported in WWEIA, NHANES 2011-2012 were identified as items consumed together as combinations. Items consumed as a combination were identified by one of fifteen unique "combination food types". Foods and beverages not coded in combination have the code "0" for the combination food type variable.
The combination types provide a linkage for:
| Combination Type | Code | Examples of Combination Type | % Items |
|---|---|---|---|
| Not in combination | 0 | NA | 57 |
| Beverage w/ additions | 1 | Coffee, tea with: milk, cream, sugar. Infant formula with: baby cereal. | 8 |
| Cereal w/ additions | 2 | Cereals (ready-to-eat, cooked, baby) with: milk, sugar, fruit, butter. | 5 |
| Bread/baked product w/additions | 3 | Breads, rolls, pancakes with: butter, jam, syrup, fruit . Cakes, pies with: ice cream, toppings. Crackers with: cheese, dip, peanut butter. | 4 |
| Salad | 4 | Components of salads that do not have a single code in FNDDS. It may also designate additional items to single code salads. | 4 |
| Sandwiches | 5 | Components of sandwiches that do not have a single code in FNDDS. It may also designate additional items added to single code sandwiches. | 10 |
| Soup | 6 | Soup with: crackers, croutons, cheese. | <1 |
| Frozen meals | 7 | Components of a prepackaged frozen meal and additions to the meal. | <1 |
| Ice cream/ frozen yogurt w/ additions | 8 | Ice cream with: syrup, nuts, toppings. | <1 |
| Dried beans or Vegetable w/ additions | 9 | French fries, potatoes with: catsup, gravy, butter, toppings. Beans with: sauce, butter. | 3 |
| Fruit w/ additions | 10 | Fruit with: toppings, milk, honey. Components of fruit mixtures or salads that do not have a single code in FNDDS. | <1 |
| Tortilla products | 11 | Components of tacos and tortilla products that do not have a single code in FNDDS. It may also designate additional items to single code tacos or tortilla products. | 1 |
| Meat, Poultry, Fish | 12 | Meat, poultry, fish with: gravy, sauce, and condiments. | 2 |
| Lunchables® | 13 | Components of pre-packaged lunch kits. | <1 |
| Chips w/ additions | 14 | Potato chips, corn chips with: dip, cheese, salsa. | <1 |
| Other mixtures | 90 | Rice, pasta, spaghetti, eggs, other mixtures with: butter, gravy, sauce, condiments. | 4 |
All items given a combination food type are given an additional variable to identify each of the items within the combination. This variable is the "combination food number" that is unique to the combination food type within the individual intake.
| Combination Coding | Variable Name, Day 1 | Variable Name, Day 2 |
|---|---|---|
| Combination food type | DR1CCMTX | DR2CCMTX |
| Combination food number | DR1CCMNM | DR2CCMNM |
Special diet: Information on whether the participant is currently on any kind of diet to lose weight or for other health-related reason and, if so, the type of diet, was provided by the variable DRQSDIET identifies whether a participant was on a special diet. The variables DRQSDT1 through DRQSDT12 and DRQSDT91 identify the type of diet(s) that the participant was following. These variables can be found in the Total Nutrient Intakes file.
Note: A participant could report more than one type of diet, and all the responses were recorded. For researchers studying this topic using data from more than one survey cycle, it is important to note that the number of response options increased from 2003-2004 to 2009-2010. There was no change in response options between 2009-2010 and 2011-2012.
Sample weights for dietary intake data: The NHANES participants were selected on the basis of a national probability design. In order to increase the number of participants for specific demographic groups, a multi-stage, unequal probability of selection design was implemented. Beginning with 2011-2012 collection the sample design includes an oversample of Asian Americans.
Sample weights are constructed that encompass the unequal probabilities of selection, as well as adjustments for non-participation by selected sample persons. In order to produce national, representative estimates, the appropriate sample weights must be used.
For the 2011-2012 NHANES, there were 13,431 persons selected; of these 9,338 were considered participants to the MEC examination and data collection. 8,519 of the MEC participants provided complete dietary intakes for Day 1 and of those providing the Day 1 data, 7,605 provided complete dietary intakes for Day 2.
Most analyses of NHANES data use data collected in the MEC and the variable WTMEC2YR should be used for the sample weights. However, for the WWEIA dietary data, different sample weights are recommended for analysis. Although attempts are made to schedule MEC exams uniformly throughout the week, proportionally more exams occur on weekend days than on weekdays. Because food intake can vary by day of the week, use of the MEC weights would disproportionately represent intakes on weekends.
A set of weights (WTDRD1) is provided that should be used when an analysis uses the Day 1 dietary recall data (either alone or when Day 1 nutrient data are used in conjunction with MEC data). The set of weights (WTDRD1) is applicable to the 8,519 participants with Day 1 data. Day 1 weights were constructed by taking the MEC sample weights (WTMEC2YR) and further adjusting for (a) the additional non-response and (b) the differential allocation by day of the week for the dietary intake data collection. These Day 1 weights are more variable than the MEC weights, and the sample size is smaller, so estimated standard errors using Day 1 data and Day 1 weights are larger than standard errors for similar estimates based on MEC weights.
When analysis is based on both days of dietary intake, only 7,605 sample participants have complete data. The NHANES protocol requires an attempt to collect the second day of dietary data at least 3 days after the first day, but the actual number of days between the two interviews is variable. A set of adjusted weights, WTDR2D, is to be used only when an analysis uses both Day 1 and Day 2 dietary data. This two-day weight was constructed for the 7,605 participants by taking the Day 1 weights (WTDRD1) and further adjusting for (a) the additional non-response for the second recall and (b) for the proportion of weekend-weekday combinations of Day 1 and Day 2 recalls.
Note that all sample weights are person-level weights and each set of dietary weights should sum to the same population control total as the MEC weights (WTMEC2YR). In addition, the MEC weights (WTMEC2YR) are appropriate for use in the analysis of the fish and shellfish consumption data (i.e., variables DRD340, DRD350A-K, DRD350AQ-JQ DRD360, DRD370A-V, and DRD370AQ-UQ) located in the Day 1 Total Nutrient Intake File (DR1TOT_G), if no other dietary data are included in the analysis. Additional explanation of sample weights and appropriate uses are included in the NHANES Analytic Guidelines. Please also refer to the on-line NHANES Tutorial for further details on other analytic issues.
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1852.3028731 to 443805.73786 | Range of Values | 8519 | 8519 | |
| . | Missing | 819 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1531.3308619 to 499271.52935 | Range of Values | 7605 | 7605 | |
| . | Missing | 1733 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1 | Reliable and met the minimum criteria | 7496 | 7496 | |
| 2 | Not reliable or not met the minimum criteria | 56 | 7552 | |
| 4 | Reported consuming breast-milk | 109 | 7661 | |
| 5 | Not done | 1677 | 9338 | |
| . | Missing | 0 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 32 to 92 | Range of Values | 7661 | 7661 | |
| . | Missing | 1677 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1 | Yes | 130 | 130 | |
| 2 | No | 8389 | 8519 | |
| . | Missing | 819 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1 | Day 1 only | 914 | 914 | |
| 2 | Day 1 and day 2 | 7605 | 8519 | |
| . | Missing | 819 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| -38 to 178 | Range of Values | 7638 | 7638 | |
| . | Missing | 1700 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1 | Sunday | 1257 | 1257 | |
| 2 | Monday | 1556 | 2813 | |
| 3 | Tuesday | 1455 | 4268 | |
| 4 | Wednesday | 1771 | 6039 | |
| 5 | Thursday | 726 | 6765 | |
| 6 | Friday | 716 | 7481 | |
| 7 | Saturday | 180 | 7661 | |
| . | Missing | 1677 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1 | English | 6813 | 6813 | |
| 2 | Spanish | 769 | 7582 | |
| 3 | English and Spanish | 75 | 7657 | |
| 4 | Other | 2 | 7659 | |
| 5 | Asian Languages | 93 | 7752 | |
| 6 | Asian Languages and English | 5 | 7757 | |
| . | Missing | 1581 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1 | SP | 5436 | 5436 | |
| 2 | Mother of SP | 1807 | 7243 | |
| 3 | Father of SP | 182 | 7425 | |
| 4 | Wife of SP | 30 | 7455 | |
| 5 | Husband of SP | 6 | 7461 | |
| 6 | Daughter of SP | 35 | 7496 | |
| 7 | Son of SP | 10 | 7506 | |
| 8 | Grandparent of SP | 42 | 7548 | |
| 9 | Friend, Partner, Non Relative | 5 | 7553 | |
| 10 | Translator, not a HH member | 1 | 7554 | |
| 11 | Child care provider, Caretaker | 10 | 7564 | |
| 12 | Other Relative | 40 | 7604 | |
| 14 | Other specify | 0 | 7604 | |
| 77 | Refused | 0 | 7604 | |
| 99 | Don't know | 0 | 7604 | |
| . | Missing | 1734 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1 | SP | 270 | 270 | |
| 2 | Mother of SP | 198 | 468 | |
| 3 | Father of SP | 32 | 500 | |
| 4 | Wife of SP | 83 | 583 | |
| 5 | Husband of SP | 17 | 600 | |
| 6 | Daughter of SP | 7 | 607 | |
| 7 | Son of SP | 2 | 609 | |
| 8 | Grandparent of SP | 5 | 614 | |
| 9 | Friend, Partner, Non Relative | 3 | 617 | |
| 10 | Translator, not a HH member | 4 | 621 | |
| 11 | Child care provider, Caretaker | 6 | 627 | |
| 12 | Other Relative | 24 | 651 | |
| 13 | No one | 6935 | 7586 | |
| 14 | Other specify | 0 | 7586 | |
| 77 | Refused | 0 | 7586 | |
| 99 | Don't know | 2 | 7588 | |
| . | Missing | 1750 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1 to 46 | Range of Values | 7605 | 7605 | |
| . | Missing | 1733 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 8213 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 355.95 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 1117.53 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 874.31 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 133.3 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 409.32 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 165.304 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 167.256 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 123.657 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 2235 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 139.35 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 118.91 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 8135 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 27618 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 82544 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 288727 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 7302 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 120068 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 182931 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 22.795 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 20.082 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 222.552 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 22.545 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 4186 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 3737 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 4186 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 6483 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 1461.9 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 75.33 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 50.03 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 3257.8 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 138.4 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 22805.3 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 14 to 9150 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 5556 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 5 to 1962 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 161.1 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 182.36 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0.02 to 14.045 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 19 to 13483 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 26156 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 701.7 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 1800 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 877 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 325.2 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 102.06 to 13123.16 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 5.426 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 3.368 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 19.576 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 10.856 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 56.725 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 23.766 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 90.398 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 41.828 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 13.764 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 150.118 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 3.687 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 3.058 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 108.42 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 17.231 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 0.642 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 3.18 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 2.562 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 2.524 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 4.942 | Range of Values | 7496 | 7496 | |
| . | Missing | 1842 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1 | Much more than usual | 427 | 427 | |
| 2 | Usual | 6263 | 6690 | |
| 3 | Much less than usual | 935 | 7625 | |
| 7 | Refused | 0 | 7625 | |
| 9 | Don't know | 36 | 7661 | |
| . | Missing | 1677 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 10665 | Range of Values | 7605 | 7605 | |
| . | Missing | 1733 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 10665 | Range of Values | 7605 | 7605 | |
| . | Missing | 1733 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 10000 | Range of Values | 7605 | 7605 | |
| . | Missing | 1733 | 9338 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1 | Community supply | 4935 | 4935 | |
| 2 | Well or rain cistern | 595 | 5530 | |
| 3 | Spring | 79 | 5609 | |
| 4 | Don't drink tap water | 1639 | 7248 | |
| 91 | Other | 0 | 7248 | |
| 99 | Don't know | 413 | 7661 | |
| . | Missing | 1677 | 9338 |
| Variable or feature | WWEIA 2003-2004 | WWEIA 2005-2006 | WWEIA 2007-2008 | WWEIA 2009-2010 | WWEIA 2011-2012 |
|---|---|---|---|---|---|
| Number of days of intake data per respondent | 2 days | 2 days | 2 days | 2 days | 2 days |
| Nutrients included | Food energy and 62 nutrients/food components. "Added vitamin E" and "Added vitamin B12" were added. | Food energy and 63 nutrients/food components. Total choline added. | Food energy and 64 nutrients/food components. Vitamin D added. | Same as 2007-2008 | Same as 2007-2008 |
| Food source (where food was obtained) |
Collected and released. Codes for 23 food sources. | Collected and released. Codes for 24 food sources; added “fundraiser sales”. | Same as 2005-2006 | Same as 2005-2006 | "Store" (value=1) has been split into three values – 1, 27 and 28. Codes 6 and 7 for cafeterias have revised descriptions. |
| Combination food types | Codes for 15 combination types; added “chips with additions”. | Same as 2003-2004 | Same as 2003-2004 | Same as 2003-2004 | Same as 2003-2004 |
| Eating occasion names | 20 codes; 3 existing codes modified and 2 new codes. | Same as 2003-2004 | Same as 2003-2004 | Same as 2003-2004 | Same as 2003-2004 |
| Special diet variables | Collected and released. | Same as 2003-2004 | Collected and released; 2 new codes: Low carbohydrate diet and High protein diet. | Same as 2005-2006 | Same as 2009-2010 |
| Plain drinking water collected in same manner as other foods and beverages | Total amount of non-sweetened water collected after the 24-hour recall and reported in the Total Nutrient Intake files. Minerals in tap water and plain bottled water not included. | All waters, including tap water and bottled water, were collected during the 24-hour recall and reported in the Individual Foods file, complete with food codes, gram weights and nutrient values. Summary water variables compatible with previous data cycles are included in the Total Nutrient Intake files with the exception of plain carbonated water. | Same as 2005-2006 | Same as 2005-2006 | Same as 2005-2006 |
| Number of intakes that include only water consumption for the day | 3 intakes (1 intake in Day 1 and 2 intakes in Day 2 data), no records in Individual Foods file. | 3 intakes (1 intake in Day 1 and 2 intakes in Day 2 data), records are included in Individual Foods file. | 5 intakes (all in Day 2 data), records are included in Individual Foods file. | 4 intakes (all in Day 2 data), records are included in Individual Foods file. | 7 intakes (1 in Day 1, 6 in Day 2), records are included in Individual Foods file. |
| Number of intakes that include no water or food consumption for the day | No such intake reported. | No such intake reported. | 2 intakes (1 intake in Day 1 and 1 intake in Day 2) with no food or water records for the day. Records are not included in the Individual Foods File for these intakes. | 1 intake in Day 2 with no food or water records for the day. Record is not included in the Individual Foods File for this intake. | No such intake reported. |
| Eligible sample for questions on fish/ shellfish consumption in the past 30 days | Children 1-5 years and women 16-49 years of age. | All participants one year or older. | Same as 2005-2006 | Same as 2005-2006 | Same as 2005-2006 |
| Number of days between the intake day and the day of family interview | Not calculated | Not calculated | Calculated and released; 2 new continuous variables calculated for both Day 1 and Day 2 | Same as 2007-2008 | Same as 2007-2008 |
| Data processing step on salt adjustment | Applied | Applied | Applied | No longer applied—for details, go to www.ars.usda.gov/ba/bhnrc/fsrg | Same as 2009-2010 |
| Day1 Name | Day2 Name | Variable Label |
|---|---|---|
| SEQN | SEQN | Respondent sequence number |
| WTDRD1 | WTDRD1 | Dietary day one sample weight |
| WTDR2D | WTDR2D | Dietary two-day sample weight |
| DR1ILINE | DR2ILINE | Food/Individual component number |
| DR1DRSTZ | DR2DRSTZ | Dietary recall status |
| DR1EXMER | DR2EXMER | Interviewer ID code |
| DRABF | DRABF | Breast-fed infant (either day) |
| DRDINT | DRDINT | Number of days of intake |
| DR1DBIH | DR2DBIH | # of days b/w intake and HH interview |
| DR1DAY | DR2DAY | Intake day of the week |
| DR1LANG | DR2LANG | Language respondent used mostly |
| DR1CCMNM | DR2CCMNM | Combination food number |
| DR1CCMTX | DR2CCMTX | Combination food type |
| DR1_020 | DR2_020 | Time of eating occasion (HH:MM) |
| DR1_030Z | DR2_030Z | Name of eating occasion |
| DR1FS | DR2FS | Source of food |
| DR1_040Z | DR2_040Z | Did you eat this meal at home? |
| DR1IFDCD | DR2IFDCD | USDA food code |
| DR1MC | DR2MC | Modification code |
| DR1IGRMS | DR2IGRMS | Grams |
| DR1IKCAL | DR2IKCAL | Energy (kcal) |
| DR1IPROT | DR2IPROT | Protein (gm) |
| DR1ICARB | DR2ICARB | Carbohydrate (gm) |
| DR1ISUGR | DR2ISUGR | Total sugars (gm) |
| DR1IFIBE | DR2IFIBE | Dietary fiber (gm) |
| DR1ITFAT | DR2ITFAT | Total fat (gm) |
| DR1ISFAT | DR2ISFAT | Total saturated fatty acids (gm) |
| DR1IMFAT | DR2IMFAT | Total monounsaturated fatty acids (gm) |
| DR1IPFAT | DR2IPFAT | Total polyunsaturated fatty acids (gm) |
| DR1ICHOL | DR2ICHOL | Cholesterol (mg) |
| DR1IATOC | DR2IATOC | Vitamin E as alpha-tocopherol (mg) |
| DR1IATOA | DR2IATOA | Added alpha-tocopherol (Vitamin E) (mg) |
| DR1IRET | DR2IRET | Retinol (mcg) |
| DR1IVARA | DR2IVARA | Vitamin A, RAE (mcg) |
| DR1IACAR | DR2IACAR | Alpha-carotene (mcg) |
| DR1IBCAR | DR2IBCAR | Beta-carotene (mcg) |
| DR1ICRYP | DR2ICRYP | Beta-cryptoxanthin (mcg) |
| DR1ILYCO | DR2ILYCO | Lycopene (mcg) |
| DR1ILZ | DR2ILZ | Lutein + zeaxanthin (mcg) |
| DR1IVB1 | DR2IVB1 | Thiamin (Vitamin B1) (mg) |
| DR1IVB2 | DR2IVB2 | Riboflavin (Vitamin B2) (mg) |
| DR1INIAC | DR2INIAC | Niacin (mg) |
| DR1IVB6 | DR2IVB6 | Vitamin B6 (mg) |
| DR1IFOLA | DR2IFOLA | Total folate (mcg) |
| DR1IFA | DR2IFA | Folic acid (mcg) |
| DR1IFF | DR2IFF | Food folate (mcg) |
| DR1IFDFE | DR2IFDFE | Folate, DFE (mcg) |
| DR1ICHL | DR2ICHL | Total choline (mg) |
| DR1IVB12 | DR2IVB12 | Vitamin B12 (mcg) |
| DR1IB12A | DR2IB12A | Added vitamin B12 (mcg) |
| DR1IVC | DR2IVC | Vitamin C (mg) |
| DR1IVD | DR2IVD | Vitamin D (D2 + D3) (mcg) |
| DR1IVK | DR2IVK | Vitamin K (mcg) |
| DR1ICALC | DR2ICALC | Calcium (mg) |
| DR1IPHOS | DR2IPHOS | Phosphorus (mg) |
| DR1IMAGN | DR2IMAGN | Magnesium (mg) |
| DR1IIRON | DR2IIRON | Iron (mg) |
| DR1IZINC | DR2IZINC | Zinc (mg) |
| DR1ICOPP | DR2ICOPP | Copper (mg) |
| DR1ISODI | DR2ISODI | Sodium (mg) |
| DR1IPOTA | DR2IPOTA | Potassium (mg) |
| DR1ISELE | DR2ISELE | Selenium (mcg) |
| DR1ICAFF | DR2ICAFF | Caffeine (mg) |
| DR1ITHEO | DR2ITHEO | Theobromine (mg) |
| DR1IALCO | DR2IALCO | Alcohol (gm) |
| DR1IMOIS | DR2IMOIS | Moisture (gm) |
| DR1IS040 | DR2IS040 | SFA 4:0 (Butanoic) (gm) |
| DR1IS060 | DR2IS060 | SFA 6:0 (Hexanoic) (gm) |
| DR1IS080 | DR2IS080 | SFA 8:0 (Octanoic) (gm) |
| DR1IS100 | DR2IS100 | SFA 10:0 (Decanoic) (gm) |
| DR1IS120 | DR2IS120 | SFA 12:0 (Dodecanoic) (gm) |
| DR1IS140 | DR2IS140 | SFA 14:0 (Tetradecanoic) (gm) |
| DR1IS160 | DR2IS160 | SFA 16:0 (Hexadecanoic) (gm) |
| DR1IS180 | DR2IS180 | SFA 18:0 (Octadecanoic) (gm) |
| DR1IM161 | DR2IM161 | MFA 16:1 (Hexadecenoic) (gm) |
| DR1IM181 | DR2IM181 | MFA 18:1 (Octadecenoic) (gm) |
| DR1IM201 | DR2IM201 | MFA 20:1 (Eicosenoic) (gm) |
| DR1IM221 | DR2IM221 | MFA 22:1 (Docosenoic) (gm) |
| DR1IP182 | DR2IP182 | PFA 18:2 (Octadecadienoic) (gm) |
| DR1IP183 | DR2IP183 | PFA 18:3 (Octadecatrienoic) (gm) |
| DR1IP184 | DR2IP184 | PFA 18:4 (Octadecatetraenoic) (gm) |
| DR1IP204 | DR2IP204 | PFA 20:4 (Eicosatetraenoic) (gm) |
| DR1IP205 | DR2IP205 | PFA 20:5 (Eicosapentaenoic) (gm) |
| DR1IP225 | DR2IP225 | PFA 22:5 (Docosapentaenoic) (gm) |
| DR1IP226 | DR2IP226 | PFA 22:6 (Docosahexaenoic) (gm) |
Energy and Macronutrients
Food energy (kcal)
Protein (gm)
Carbohydrate (gm)
Fat, total (gm)
Alcohol (gm)
Sugars, total (gm)
Dietary fiber, total (gm)
Water (moisture) (gm)*
Saturated fatty acids, total (gm)
Monounsaturated fatty acids, total (gm)
Polyunsaturated fatty acids, total (gm)
Cholesterol (mg)
Individual fatty acids:
4:0 (gm)
6:0 (gm)
8:0 (gm)
10:0 (gm)
12:0 (gm)
14:0 (gm)
16:0 (gm)
18:0 (gm)
16:1 (gm)
18:1 (gm)
20:1 (gm)
22:1 (gm)
18:2 (gm)
18:3 (gm)
18:4 (gm)
20:4 (gm)
20:5 n-3 (gm)
22:5 n-3 (gm)
22:6 n-3 (gm)
Vitamins, Minerals, and Other Components
Vitamin A as retinol activity equivalents (mcg)
Retinol (mcg)
Carotenoids:
Carotene, alpha (mcg)
Carotene, beta (mcg)
Cryptoxanthin, beta (mcg)
Lycopene (mcg)
Lutein + zeaxanthin (mcg)
Vitamin E as alpha-tocopherol (mg)
Added vitamin E as alpha-tocopherol (mg)
Vitamin D (D2 + D3) (mcg)
Vitamin K as phylloquinone (mcg)
Vitamin C (mg)
Thiamin (mg)
Riboflavin (mg)
Niacin (mg)
Vitamin B-6 (mg)
Folate, total (mcg)
Folate as dietary folate equivalents (mcg)
Folic acid (mcg)
Food folate (mcg)
Choline, total (mg)
Vitamin B-12 (mcg)
Added vitamin B-12 (mcg)
Calcium (mg)
Iron (mg)
Magnesium (mg)
Phosphorus (mg)
Potassium (mg)
Sodium (mg)
Zinc (mg)
Copper (mg)
Selenium (mcg)
Caffeine (mg)
Theobromine (mg)
__________________________________________________________________________
* Value reflects moisture present in all foods, beverages, and water consumed as a beverage (variables DR1IMOIS, DR2IMOIS, DR1TMOIS, DR2TMOIS)
Two supporting files are also included with the Individual Foods files: the Food Code Description file (DRXFCD_G) and the Modification Code Description file (DRXMCD_G).
The DRXFCD_G file includes abbreviated descriptions (up to 80 characters) and complete descriptions (up to 200 characters) associated with each USDA food code identified in the Individual Foods files. The DRXMCD_G file includes descriptions (up to 200 characters) associated with each modification code identified in the Individual Foods files. Modification codes represent adjustments to predefined recipe ingredients that reflect more closely the food as described by the respondent.
The Food Code Description file (DRXFCD_G) contains three variables:
DRXFDCD a numeric value corresponding to DR1IFDCD in the file DR1IFF_G or DR2IFDCD in the file DR2IFF_G;
DRXFCSD a short description (up to 80 characters) of the food code;
DRXFDLD a long description (up to 200 characters) of the food code.
The Modification Code Description file (DRXMCD_G) contains two variables:
DRXMC a numeric value corresponding to DR1MC in the file DR1IFF_G or DR2MC in the file DR2IFF_G;
DRXMCD a description (up to 200 characters) of the modification code.
The following SQL code is an example of appending the modifications code description (here called DR1MCD) to one of the Individual Foods files. This code is for SAS® Proc SQL. Other SQL implementations may be different. This same technique may be used for the Food Code Description file as well.
proc sql; create table DR1IFF_G_PLUS as select a.*, b.DRXMCD as DR1MCD from NHANES.DR1IFF_G a left join NHANES.DRXMCD_G b on a.DR1MC = b.DRXMC order by SEQN, DR1ILINE; quit;
SAS® users may wish to use Proc Format to assign labels to the food codes or to the modification codes. The following example assigns a permanent format to the food code based on the short description. It is assumed that the user has stored the Individual Foods files and the Food Code Description file in a library called NHANES and wishes to store the formats there as well.
options fmtsearch = (NHANES);
data DRXFMT;
set NHANES.DRXFCD_G;
retain FMTNAME 'DRIFDCD';
rename DRDIFDCD = start;
rename DRXFCSD = value;
drop DRXFCLD;
run;
proc format cntlin = DRXFMT
library = NHANES;
run;
proc datasets lib = NHANES;
modify DR1IFFC;
format DR1IFDCD DRDIFDCD.;
modify DR2IFFC;
format DR2IFDCD DRDIFDCD.;
quit;
__________________________________________________________________________
SAS® is a registered trademark of SAS Institute, Inc.
| Day1 Name | Day2 Name | Variable Label |
|---|---|---|
| SEQN | SEQN | Respondent sequence number |
| WTDRD1 | WTDRD1 | Dietary day one sample weight |
| WTDR2D | WTDR2D | Dietary two-day sample weight |
| DR1DRSTZ | DR2DRSTZ | Dietary recall status |
| DR1EXMER | DR2EXMER | Interviewer ID code |
| DRABF | DRABF | Breast-fed infant (either day) |
| DRDINT | DRDINT | Number of days of intake |
| DR1DBIH | DR2DBIH | # of days b/w intake and HH interview |
| DR1DAY | DR2DAY | Intake day of the week |
| DR1LANG | DR2LANG | Language respondent used mostly |
| DR1MNRSP | DR2MNRSP | Main respondent for this interview |
| DR1HELPD | DR2HELPD | Helped in responding for this interview |
| DBQ095Z | N/A | Type of table salt used |
| DBD100 | N/A | How often add salt to food at table |
| DRQSPREP | N/A | Salt used in preparation? |
| DRQSDIET | N/A | On special diet? |
| DRQSDT1 | N/A | Weight loss/Low calorie diet |
| DRQSDT2 | N/A | Low fat/Low cholesterol diet |
| DRQSDT3 | N/A | Low salt/Low sodium diet |
| DRQSDT4 | N/A | Sugar free/Low sugar diet |
| DRQSDT5 | N/A | Low fiber diet |
| DRQSDT6 | N/A | High fiber diet |
| DRQSDT7 | N/A | Diabetic diet |
| DRQSDT8 | N/A | Weight gain/Muscle building diet |
| DRQSDT9 | N/A | Low carbohydrate diet |
| DRQSDT10 | N/A | High protein diet |
| DRQSDT11 | N/A | Gluten-free/Celiac diet |
| DRQSDT12 | N/A | Renal/Kidney diet |
| DRQSDT91 | N/A | Other special diet |
| DR1TNUMF | DR2TNUMF | Number of foods reported |
| DR1TKCAL | DR2TKCAL | Energy (kcal) |
| DR1TPROT | DR2TPROT | Protein (gm) |
| DR1TCARB | DR2TCARB | Carbohydrate (gm) |
| DR1TSUGR | DR2TSUGR | Total sugars (gm) |
| DR1TFIBE | DR2TFIBE | Dietary fiber (gm) |
| DR1TTFAT | DR2TTFAT | Total fat (gm) |
| DR1TSFAT | DR2TSFAT | Total saturated fatty acids (gm) |
| DR1TMFAT | DR2TMFAT | Total monounsaturated fatty acids (gm) |
| DR1TPFAT | DR2TPFAT | Total polyunsaturated fatty acids (gm) |
| DR1TCHOL | DR2TCHOL | Cholesterol (mg) |
| DR1TATOC | DR2TATOC | Vitamin E as alpha-tocopherol (mg) |
| DR1TATOA | DR2TATOA | Added alpha-tocopherol (Vitamin E) (mg) |
| DR1TRET | DR2TRET | Retinol (mcg) |
| DR1TVARA | DR2TVARA | Vitamin A, RAE (mcg) |
| DR1TACAR | DR2TACAR | Alpha-carotene (mcg) |
| DR1TBCAR | DR2TBCAR | Beta-carotene (mcg) |
| DR1TCRYP | DR2TCRYP | Beta-cryptoxanthin (mcg) |
| DR1TLYCO | DR2TLYCO | Lycopene (mcg) |
| DR1TLZ | DR2TLZ | Lutein + zeaxanthin (mcg) |
| DR1TVB1 | DR2TVB1 | Thiamin (Vitamin B1) (mg) |
| DR1TVB2 | DR2TVB2 | Riboflavin (Vitamin B2) (mg) |
| DR1TNIAC | DR2TNIAC | Niacin (mg) |
| DR1TVB6 | DR2TVB6 | Vitamin B6 (mg) |
| DR1TFOLA | DR2TFOLA | Total folate (mcg) |
| DR1TFA | DR2TFA | Folic acid (mcg) |
| DR1TFF | DR2TFF | Food folate (mcg) |
| DR1TFDFE | DR2TFDFE | Folate, DFE (mcg) |
| DR1TCHL | DR2TCHL | Total choline (mg) |
| DR1TVB12 | DR2TVB12 | Vitamin B12 (mcg) |
| DR1TB12A | DR2TB12A | Added vitamin B12 (mcg) |
| DR1TVC | DR2TVC | Vitamin C (mg) |
| DR1TVD | DR2TVD | Vitamin D (D2 + D3) (mcg) |
| DR1TVK | DR2TVK | Vitamin K (mcg) |
| DR1TCALC | DR2TCALC | Calcium (mg) |
| DR1TPHOS | DR2TPHOS | Phosphorus (mg) |
| DR1TMAGN | DR2TMAGN | Magnesium (mg) |
| DR1TIRON | DR2TIRON | Iron (mg) |
| DR1TZINC | DR2TZINC | Zinc (mg) |
| DR1TCOPP | DR2TCOPP | Copper (mg) |
| DR1TSODI | DR2TSODI | Sodium (mg) |
| DR1TPOTA | DR2TPOTA | Potassium (mg) |
| DR1TSELE | DR2TSELE | Selenium (mcg) |
| DR1TCAFF | DR2TCAFF | Caffeine (mg) |
| DR1TTHEO | DR2TTHEO | Theobromine (mg) |
| DR1TALCO | DR2TALCO | Alcohol (gm) |
| DR1TMOIS | DR2TMOIS | Moisture (gm) |
| DR1TS040 | DR2TS040 | SFA 4:0 (Butanoic) (gm) |
| DR1TS060 | DR2TS060 | SFA 6:0 (Hexanoic) (gm) |
| DR1TS080 | DR2TS080 | SFA 8:0 (Octanoic) (gm) |
| DR1TS100 | DR2TS100 | SFA 10:0 (Decanoic) (gm) |
| DR1TS120 | DR2TS120 | SFA 12:0 (Dodecanoic) (gm) |
| DR1TS140 | DR2TS140 | SFA 14:0 (Tetradecanoic) (gm) |
| DR1TS160 | DR2TS160 | SFA 16:0 (Hexadecanoic) (gm) |
| DR1TS180 | DR2TS180 | SFA 18:0 (Octadecanoic) (gm) |
| DR1TM161 | DR2TM161 | MFA 16:1 (Hexadecenoic) (gm) |
| DR1TM181 | DR2TM181 | MFA 18:1 (Octadecenoic) (gm) |
| DR1TM201 | DR2TM201 | MFA 20:1 (Eicosenoic) (gm) |
| DR1TM221 | DR2TM221 | MFA 22:1 (Docosenoic) (gm) |
| DR1TP182 | DR2TP182 | PFA 18:2 (Octadecadienoic) (gm) |
| DR1TP183 | DR2TP183 | PFA 18:3 (Octadecatrienoic) (gm) |
| DR1TP184 | DR2TP184 | PFA 18:4 (Octadecatetraenoic) (gm) |
| DR1TP204 | DR2TP204 | PFA 20:4 (Eicosatetraenoic) (gm) |
| DR1TP205 | DR2TP205 | PFA 20:5 (Eicosapentaenoic) (gm) |
| DR1TP225 | DR2TP225 | PFA 22:5 (Docosapentaenoic) (gm) |
| DR1TP226 | DR2TP226 | PFA 22:6 (Docosahexaenoic) (gm) |
| DR1_300 | DR2_300 | Compare food consumed yesterday to usual |
| DR1_320Z | DR2_320Z | Total plain water drank yesterday (gm) |
| DR1_330Z | DR2_330Z | Total tap water drank yesterday (gm) |
| DR1BWATZ | DR2BWATZ | Total bottled water drank yesterday (gm) |
| DR1TWS | DR2TWS | Tap water source |
| DRD340 | N/A | Shellfish eaten during past 30 days |
| DRD350A | N/A | Clams eaten during past 30 days |
| DRD350AQ | N/A | # of times clams eaten in past 30 days |
| DRD350B | N/A | Crabs eaten during past 30 days |
| DRD350BQ | N/A | # of times crabs eaten in past 30 days |
| DRD350C | N/A | Crayfish eaten during past 30 days |
| DRD350CQ | N/A | # of times crayfish eaten past 30 days |
| DRD350D | N/A | Lobsters eaten during past 30 days |
| DRD350DQ | N/A | # of times lobsters eaten past 30 days |
| DRD350E | N/A | Mussels eaten during past 30 days |
| DRD350EQ | N/A | # of times mussels eaten in past 30 days |
| DRD350F | N/A | Oysters eaten during past 30 days |
| DRD350FQ | N/A | # of times oysters eaten in past 30 days |
| DRD350G | N/A | Scallops eaten during past 30 days |
| DRD350GQ | N/A | # of times scallops eaten past 30 days |
| DRD350H | N/A | Shrimp eaten during past 30 days |
| DRD350HQ | N/A | # of times shrimp eaten in past 30 days |
| DRD350I | N/A | Other shellfish eaten past 30 days |
| DRD350IQ | N/A | # of times other shellfish eaten |
| DRD350J | N/A | Other unknown shellfish eaten past 30 d |
| DRD350JQ | N/A | # of times other unknown shellfish eaten |
| DRD350K | N/A | Refused on shellfish eaten past 30 days |
| DRD360 | N/A | Fish eaten during past 30 days |
| DRD370A | N/A | Breaded fish products eaten past 30 days |
| DRD370AQ | N/A | # of times breaded fish products eaten |
| DRD370B | N/A | Tuna eaten during past 30 days |
| DRD370BQ | N/A | # of times tuna eaten in past 30 days |
| DRD370C | N/A | Bass eaten during past 30 days |
| DRD370CQ | N/A | # of times bass eaten in past 30 days |
| DRD370D | N/A | Catfish eaten during past 30 days |
| DRD370DQ | N/A | # of times catfish eaten in past 30 days |
| DRD370E | N/A | Cod eaten during past 30 days |
| DRD370EQ | N/A | # of times cod eaten in past 30 days |
| DRD370F | N/A | Flatfish eaten during past 30 days |
| DRD370FQ | N/A | # of times flatfish eaten past 30 days |
| DRD370G | N/A | Haddock eaten during past 30 days |
| DRD370GQ | N/A | # of times haddock eaten in past 30 days |
| DRD370H | N/A | Mackerel eaten during past 30 days |
| DRD370HQ | N/A | # of times mackerel eaten past 30 days |
| DRD370I | N/A | Perch eaten during past 30 days |
| DRD370IQ | N/A | # of times perch eaten in past 30 days |
| DRD370J | N/A | Pike eaten during past 30 days |
| DRD370JQ | N/A | # of times pike eaten in past 30 days |
| DRD370K | N/A | Pollock eaten during past 30 days |
| DRD370KQ | N/A | # of times pollock eaten in past 30 days |
| DRD370L | N/A | Porgy eaten during past 30 days |
| DRD370LQ | N/A | # of times porgy eaten in past 30 days |
| DRD370M | N/A | Salmon eaten during past 30 days |
| DRD370MQ | N/A | # of times salmon eaten in past 30 days |
| DRD370N | N/A | Sardines eaten during past 30 days |
| DRD370NQ | N/A | # of times sardines eaten past 30 days |
| DRD370O | N/A | Sea bass eaten during past 30 days |
| DRD370OQ | N/A | # of times sea bass eaten past 30 days |
| DRD370P | N/A | Shark eaten during past 30 days |
| DRD370PQ | N/A | # of times shark eaten in past 30 days |
| DRD370Q | N/A | Swordfish eaten during past 30 days |
| DRD370QQ | N/A | # of times swordfish eaten past 30 days |
| DRD370R | N/A | Trout eaten during past 30 days |
| DRD370RQ | N/A | # of times trout eaten in past 30 days |
| DRD370S | N/A | Walleye eaten during past 30 days |
| DRD370SQ | N/A | # of times walleye eaten in past 30 days |
| DRD370T | N/A | Other fish eaten during past 30 days |
| DRD370TQ | N/A | # of times other fish eaten past 30 days |
| DRD370U | N/A | Other unknown fish eaten in past 30 days |
| DRD370UQ | N/A | # of times other unknown fish eaten |
| DRD370V | N/A | Refused on fish eaten past 30 days |