This paper describes the results of the first national study to describe Head Start program practices in three areas: assessing body mass index (BMI), addressing food insecurity, and determining children’s portion sizes. Researchers found that nearly all programs (99.5%) reported obtaining height and weight data, but not all calculated BMI or discussed height and weight measurements with families. Many program directors reported that their staff saw children who appeared not to be getting enough food to eat at home, and described subsequent forms of direct and indirect assistance provided to the families. Differing strategies were reported for how programs determined portion size, including food arriving already portioned on children’s plates (6%), staff determining portion sizes for children (39%), and programs allowing children to decide their own portions (55%).