• Component Description
• Data Processing and Editing
• Analytic Notes
• Codebook
  • IFPID - Formula product ID number
  • IFNAME - Formula name
  • IFNID - Nutrient ID number
  • IFNUNAME - Nutrient name
  • NUOPER - Nutrient Operator
  • NUQNTY - Nutrient quantity
  • NUUNIT - Nutrient unit
  • NUCAT - Nutrient category
• Appendix 1: Rules for Classifying Nutrient Category

National Health and Nutrition Examination Survey

2019-March 2020 Data Documentation, Codebook, and Frequencies

Infant Formula Database – Nutrient Information (IFNI_K_R)

RDC Only Data File: IFNI_K_R.xpt

First Published: April 2023

Last Revised: NA

Due to disclosure issues, this dataset is not available publicly. Access may be obtained through the NCHS Research Data Center (https://www.cdc.gov/rdc).

Component Description

The NHANES program suspended field operations in March 2020 due to the coronavirus disease 2019 (COVID-19) pandemic. As a result, data collection for the NHANES 2019-2020 cycle was not completed. Data collected in 2019-March 2020 can be accessed as convenience samples through the NCHS Research Data Center (RDC). Any analyses based solely on the 2019-March 2020 data would not be generalizable to the U.S. civilian non-institutionalized population. Please refer to the Analytic Notes section for more details on the use of the data.

The Infant Formula Questionnaire (IFQ) section provides information on infant formula consumed by survey participants aged 0-24 months old during the 14-day period prior to the interview. In 2019, additional questions on infant feeding and introduction of first foods were added to the survey to fill gaps in scientific knowledge and support evidence-based programs and policies related to early childhood nutrition (see details at: DB24_K_R). To complement these data, the infant formula questions were also added in 2019 to capture infant formulas consumed by survey participants (see details at: IFQF_K_R). Analysts are encouraged to read the documentations to understand the structure of these files.

The NHANES Infant Formula Database (NHANES IFD) contains detailed information on the Infant Formulas (IF) reported in IFQ. The NHANES-IFD release consists of four datasets containing information on the following: Infant Formula Product Information (IFPI), Infant Formula Nutrient Information (IFNI), Infant Formula Ingredient Information (IFII), and Infant Formula Label Descriptor (IFLD). These files incorporate all products that have been reported by respondents in the 2019–March 2020 survey. 

The NHANES IFD is maintained by NHANES nutritionists. Attempts were made to obtain a product label for all reported infant formulas from sources such as the manufacturer or retailer, the Internet, and company catalogs. Selected label information was then entered into the IFD including, but not limited to: supplement name; manufacturer and/or distributor; serving size; form of serving size; nutrients and amounts; and ingredients. The nutrient information entered into the database was taken directly from the nutrient list on the label or carton. The IFD was used to assist with data editing and then made available to the public in four data files (IFPI, IFNI, IFII, and IFLD).

In addition to entering labels into the IF database, NHANES nutritionists also created and maintained generic infant formulas in the database. Generics were created in the database when a reported formula has partial information provided, such as a store brand formula name and the manufacturer, but no ingredient information available. Private label manufacturers often make products with identical ingredients and nutrient content for different brands. These generic IFs were linked to the ingredients and nutrient content of another product with identical manufacturer and product characteristics. For example, a Brand X Gentle Infant Formula Milk-based Powder was reported, but no label information on ingredient or nutrient content was located. However, there is a label for Brand Y Gentle Infant Formula Milk-based Powder, made by the same manufacturer, in the NHANES IFD. A generic record would be created in the IFD for the Brand X product with ingredient and nutrient content information from Brand Y. 

Data Processing and Editing

The NHANES IFD was used for processing and editing of the infant formula data.

IFPID: Infant Formula Product ID Number
A unique number assigned to each product entered in the NHANES IFD.

IFNAME: Name of Infant Formula
The name from the front of the product label. The brand name was generally entered first (i.e., Enfamil), followed by the actual product name (i.e., Gentle). Information such as the formula base (i.e., milk-based) of the product, formula form (i.e., Powder, Ready to Use), and other label descriptors that help distinguish a product from a similar product (i.e., DHA, Lutein, Vitamin E,) were also included if they were on the front of the product label. 

IFBASE: Formula Base
The base (i.e., Milk, Soy) of the formula from the front of the product label.

IFTARGET: Formula Target
The target (i.e., Newborn, Infant, Toddler, Combined Infant/Toddler) of the formula, usually found on the front of the label.

IFFORM: Formula Form
The form (i.e., Powder, Ready to Use, Liquid Concentrate) of the formula, usually found on the front of the label.

IFCONAG: Formula Consumer Age
The consumer age (i.e., 0-3 Months, 0-12 Months, 6-12 Months, 12 Months & Up, etc.) of the formula, usually found on the front of the label.

IFSERQNT: Formula Serving Quantity
The quantity of the formula serving size.

IFSERUNT: Formula Serving Unit
The unit (scoop, fluid ounces, bottle, cup, etc.) of the formula serving size.

IFVERSION: Formula Version
The formula version. All formulas started at version 1.

IFSOURCE: Formula Source
The source (i.e., Product Label, Product Catalog, Internet, etc.) of each formula label recorded in the IFD.

IFNID: Nutrient ID Number
The new unique nutrient ID created by the IFD for each nutrient recorded from the product label’s nutrient list.

IFNUNAME: Nutrient Name
Nutrient names were recorded from the product label’s nutrient list.

NUOPER: Nutrient Operator
A symbol =, <, or > that came from the product label’s nutrient list.

NUQNTY: Nutrient Quantity
Nutrient quantity were recorded for each nutrient listed from the product label’s nutrient list. 

NUUNIT: Nutrient Unit
Nutrient unit were recorded for each nutrient listed from the product label’s nutrient list.

NUCAT: Nutrient Category
Nutrient categories included: Vitamin, Mineral, Amino Acid, Essential Fatty Acid, Prebiotic, Probiotic, Other. These were assigned by NHANES staff. (Please see Appendix 1: Rules for Classifying Nutrient Category.)

IFIID: Ingredient ID Number
The new unique ingredient ID created by the IFD for each ingredient recorded from the product label.

IFINNAME: Ingredient Name
Ingredient names were recorded from the product label.

IFLDID: Label Descriptor ID Number
The new unique label descriptor ID created by the IFD for each description recorded from the product label.

IFLDNAME: Label Descriptor Name
Label descriptor names were recorded from the product label.

The NHANES IFD contains information on all IF reported from 2019-March 2020. These data are made available to the public in four files. See below for the file layout for each individual dataset. These four datasets can be linked by infant formula product ID number (IFPID), which is a unique product identifier. 

 

(IFPI): Infant Formula Product Information

Variable Name	Variable Description
IFPID	Formula product ID number
IFNAME	Formula name
IFBASE	Formula base
IFTARGET	Formula target
IFFORM	Formula form
IFCONAG	Formula consumer age
IFSERQNT	Formula serving quantity
IFSERUNT	Formula Serving unit
IFVERSION	Formula version
IFSOURCE	Formula source

 

(IFNI): Infant Formula Nutrient Information

Variable Name	Variable Description
IFPID	Formula product ID number
IFNAME	Formula name
IFNID	Nutrient ID number
IFNUNAME	Nutrient name
NUOPER	Nutrient Operator
NUQNTY	Nutrient quantity
NUUNIT	Nutrient unit
NUCAT	Nutrient category

 

(IFII): Infant Formula Ingredient Information

Variable Name	Variable Description
IFPID	Formula product ID number
IFNAME	Formula name
IFIID	Ingredient ID number
IFINNAME	Ingredient name

 

(IFLD): Infant Formula Label Descriptor

Variable Name	Variable Description
IFPID	Formula product ID number
IFNAME	Formula name
IFLDID	Label Descriptor ID number
IFLDNAME	Label Descriptor name

 

Analytic Notes

The COVID-19 pandemic required suspension of NHANES 2019-2020 field operations in March 2020 after data were collected in 18 of the 30 survey locations in the 2019-2020 sample. Data collection was cancelled for the remaining 12 locations. Calculation of survey weights for this partial cycle is not possible due to incomplete data collection. Therefore, data from survey components that were only collected in 2019-March 2020 are made available as convenience samples through NCHS's Research Data Center (RDC) because unbiased estimates for the NHANES target population cannot be produced with these samples.

For survey components conducted in both 2017-2018 and 2019-2020 cycles, data collected from 2019 to March 2020 were combined with data from 2017 to 2018 to form a nationally representative sample of NHANES 2017-March 2020 pre-pandemic data. Please see the NHANES 2017-March 2020 pre-pandemic data page for detailed information on this combined sample.

Source of Product Information
The best source of product information is the label itself, but when this cannot be obtained, other sources are used. Information from other sources may not always be an accurate reflection of what is actually on the infant formula label. This is true for the infant formula’s apparent name as well as for the nutrients. The apparent name on the container is most important, since interviewers see the infant formula container and record the name as it appears to them. Differences from what appears on the label are particularly noted for information from the Internet (name and nutrients), and infant formula carton (name). In addition, infant formula companies may change the appearance of a label and thus the apparent name without changing the content or may change content with minimal change to the label, or may change both. Attempts were made to obtain updated labels as they come onto the market, but cannot guarantee complete success. The source of the infant formula information (i.e., IFSOURCE) is included in the IFPI dataset.

Using Self-Reported Data
NHANES data are self-reported and recorded by interviewers, and thus may contain inconsistencies or errors. Some inconsistencies have been edited; however, users may notice additional inconsistencies. Users are advised to assess the data and edit it as deemed appropriate for the analyses being undertaken.

Codebook and Frequencies