In 2006, FNS asked the Institute of Medicine to review the WIC food packages. The IOM proposed major changes to improve nutrition and encourage breastfeeding but also expressed the concern that changes related to partial breastfeeding may have unintended consequences. The IOM recommended that FNS conduct an impact study evaluating the birth month breastfeeding changes to the WIC food packages. 

WIC Participant and Program Characteristics summarizes the demographic characteristics of nationwide participants in April 2010. It includes information on participant income and nutrition risk characteristics, estimates breastfeeding initiation rates for WIC infants, and describes WIC members of migrant farm-worker families.