The WIC program offers supplemental foods to low-income women, infants, and children. This study compared consumption patterns of WIC children with those of three different comparison groups: eligible nonparticipating children living in non-WIC households, eligible nonparticipating children living in WIC households, and children living in households whose income is too high to be eligible for WIC. The study provides strong evidence that participation in the WIC program increases consumption of at least some types of WIC-approved foods. Although WIC-participating children consumed significantly more calories from WIC-approved foods than children in the two comparison groups of eligible nonparticipants, there was no significant difference in total calories consumed. The results suggest that WIC foods replace non-WIC foods in the diets of children participating in WIC rather than adding to their food consumption. This is the first study to examine in detail children's consumption of WIC-approved foods by WIC status. Understanding WIC's effect on the consumption of foods contained in the WIC food packages can help inform decisions on possible changes to the packages.