The National WIC Evaluation: evaluation of the Special Supplemental Food Program for Women, Infants, and Children. I. Background and introduction

The Special Supplemental Food Program for Women, Infants, and Children (WIC) aims to improve the nutrition and health of low-income, nutritionally at-risk pregnant women and preschool children with supplemental food, nutrition education, and coordination of health care. Started in 1972, it recently served greater than 3.4 million persons monthly and at a cost of $1.66 billion annually. The National WIC Evaluation (NWE) consisted of four studies: The historical study estimated changes in birth outcome attributable to WIC from 1972 to 1980 in 19 states and the District of Columbia from WIC program data and vital statistics. The longitudinal study of pregnant women compared dietary intake, weight gain, anthropometry, duration of gestation, birth weight, and infant length and head circumference between a representative national sample of WIC participants and economically comparable women. The cross-sectional study of preschool children related WIC to dietary intake, anthropometry, and psychological development. The food expenditures study estimated the impact of WIC on family grocery and other food expenditures.