In 2007, USDA introduced a new set of food packages via an Interim Rule based on recommendations from the Institute of Medicine, which were implemented by October 2009. The contents of the food packages were finalized via a Final Rule in 2014. The Final Rule clarified some provisions in the Interim Rule and allowed some additional options and substitutions.

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.