At A Glance

Noteworthy Characteristics

  • Tracks feeding behaviors of infants through the first year of life.
  • Provides detailed information on infant feeding patterns.
  • Large sample size.
  • Includes mothers and infants participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).
  • Data were collected at 1 to 2 month intervals.
  • Prospective design.
  • Includes data on prenatal maternal diet and maternal diet when infant is age 3 months.
  • Includes data on infant sleep and sleep environment.
  • Year six follow-up provides ability to link early feeding patterns with outcomes at age 6 years



To collect data about feeding practices and patterns for infants in their first year of life in the United States (U.S.).

Target Population

Women and their healthy, full-term infants weighing 5 pounds or more at birth in the U.S.


Began in 2005. Conducted every 1 to 2 months for 15 months. Most recent year conducted was 2007. Survey ended in 2007. A follow-up study was conducted in 2012.

The Neonatal Questionnaire was sent to the mother when her infant was approximately 3 weeks old. Postnatal questionnaires were mailed to the mother approximately monthly from the time her infant was 2 months through 7 months of age, then three times (about every 7 weeks) until 12 months of age.


Centers for Disease Control and Prevention, U.S. Department of Health and Human Services; Food and Drug Administration, U.S. Department of Health and Human Services

Special Note(s)

Between March and June of 2012, FDA and CDC conducted the Year Six Follow-Up Study (Y6FU) to characterize the health, development, and diet quality of children who participated in the IFPS II. To qualify for Y6FU, the mother had to have answered at least the prenatal and neonatal IFPS II questionnaires and not have been disqualified afterwards due to some medical reasons that affected infant feeding.


Sample Design

Longitudinal survey with convenience sample. To maximize participation rates, the study selected the sample from a national consumer opinion panel of 500,000 households across the U.S. Learn more about the sampling design.

Sample Size

Approximately 2,000 women and their infants in 2006. Of 2,958 mothers who qualified for Y6FU based on IFPS II, 1,542 women participated in the follow-up study yielding a response rate of 52.1%.

Special Note(s)

The sample is not representative of the U.S. population.

Key Variables


NameMethods of Assessment
Age of all household membersInterview/questionnaire
Disability (general)Interview/questionnaire
Household incomeInterview/questionnaire
Household sizeInterview/questionnaire
Marital statusInterview/questionnaire
Mother’s educationInterview/questionnaire
Mother’s employment statusInterview/questionnaire
Mother’s race/ethnicityInterview/questionnaire
Participation in Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)Interview/questionnaire
Sex of all household membersInterview/questionnaire
State of residenceInterview/questionnaire


NameMethods of Assessment
Breastfeeding and formula feeding practicesInterview/questionnaire
Dietary supplement and herbal intakes by infantsProxy report (mother)
Maternal diet (prenatal and 3 months after birth)Modified food frequency questionnaire
Other feeding practices and patterns at different times during the first yearProxy report (mother)
Relative contribution to infant’s diet of breast milk and formulaInterview/questionnaire
Types of solid foods consumed by childProxy report (mother) – infant food frequency checklist
Availability of healthful snacks*Interview/questionnaire

Physical Activity-Related

NameMethods of Assessment
Mother’s physical activity level*Interview/questionnaire
Child's physical activity level*Interview/questionnaire
Child's screen time*Interview/questionnaire


NameMethods of Assessment
Daytime fatigue/sleepiness and/or alertnessQuestionnaire
Physical sleep environment: Items needed for sleep (e.g., stuffed animal, pacifier)Questionnaire
Sleep-related behaviors: Infant sleep positionQuestionnaire
Sleep disturbances and quality: Other (list variable)Questionnaire
Sleep duration and quantity: Total sleep timeQuestionnaire
Social determinants of health (e.g., income, racial discrimination)Questionnaire
Social sleep environment: Co-sleeping with infantQuestionnaire
Social sleep environment: Shared bedroom/bedQuestionnaire
Social sleep environment: Sleep location (e.g., living room)Questionnaire
Social sleep environment: Other (list variable)Questionnaire


NameMethods of Assessment
Infant weight and lengthProxy report (mother)
Mother’s weight and heightSelf report


NameMethods of Assessment

Special Note(s)

* Included in Y6FU data.

Data Access and Cost

Data Availability

Obtain data by sending an e-mail request to stating the purpose of the study and briefly describing the planned analysis.


Free of charge.


Geocode Variable(s)

State of residence.

Existing Linkages

None noted.

Selected Publications


Fein, SB, Mandal B, Roe BE. Success of strategies for combining employment and breastfeeding. Pediatrics 2008:122(2):S56-S62.

Grimm KA, Kim SA, Yaroch AL, Scanlon KS. Fruit and vegetable intake during infancy and early childhood. Pediatrics. 2014 Sep;134 Suppl 1:S63-9.

Li R, Fein SB, Chen J, Grummer-Strawn LM. Why mothers stop breastfeeding: Mothers' self-reported reasons for stopping during the first year. Pediatrics 2008;122(Suppl 2):S69-S76.

Li R, Fein SB, Grummer-Strawn LM. Do infants fed from a bottle lack self-regulation of milk intake compared with infants fed directly from the breast? Pediatrics 2010;125(6):e1386-e1393.

Li R, Fein SB, Grummer-Strawn LM. Association of breastfeeding intensity and bottle emptying behaviors at early infancy with infants' risk for excess weight at late infancy. Pediatrics 2008;122(Suppl 2):S77-S84.

Mandal B, Roe BE, Fein SB. The differential effects of full-time and part-time work status on breastfeeding. Health Policy 2010;97(1):79-86.

Shealy, KR, Scanlon KS, Labiner-Wolfe J, Fein SB, Grummer-Strawn LM. Characteristics of breastfeeding practices among U.S. mothers. Pediatrics 2008;122(Suppl 2):S50-S55.


Leonard SA, Labiner-Wolfe J, Geraghty SR, Rasmussen KM. Associations between high prepregnancy body mass index, breast-milk expression, and breast-milk production and feeding. American Journal of Clinical Nutrition 2011;93:556-563.

Leonard SA, Rasmussen KM. Larger infant size at birth reduces the negative association between maternal prepregnancy body mass index and breastfeeding duration. The Journal of Nutrition 2011;141:645-653.

Li R, Magadia J, Fein SB, Grummer-Strawn LM. “The Risk of Bottle Feeding for Rapid Weight Gain during the First Year of Life.” Archives of Pediatrics and Adolescent Medicine. 2012; (May).


Fein, SB, Labiner-Wolfe J, Shealy K, Li R, Chen J, Grummer-Strawn LM. Infant Feeding Practices Study II: Study methods. Pediatrics 2008;122(Suppl 2):S28-S35.