may include overcrowded conditions or the need for students to use other food sources, such as school stores or vending machines, to obtain food, thus increasing the relative attractiveness of competitive foods.

Closely related to issues concerning cafeteria space are broader constraints that schools face for scheduling. Under pressure to ensure high academic performance (or to provide time for other school priorities), some schools schedule relatively short lunch periods. This may lead some students to choose competitive foods and beverages rather than NSLP meals if these can be purchased more quickly. A related timing issue involves whether schedules are such that students choose between buying and consuming an NSLP meal or having more recess time. Also, for high school students, there may be choices between having time for lunch and having time for an extra class or other academic opportunity.

Some schools, particularly high schools, choose to “open” their campuses to allow students to be away from school during lunch periods and, in some instances, during other times when the students do not have classes scheduled. Nationally, 94 percent of elementary, 89 percent of middle, and 73 percent of high schools have closed campuses (Wechsler et al., 2001). Some schools have an open campus because of space constraints such as those noted above; in other instances, the school district may have made a conscious decision to allow older students to come and go from campus based on the assumption that they have a higher level of responsibility.

The open campus environment affects the dynamic of the interaction between the NSLP and competitive foods and beverages. In large part this is true because being able to leave the campus at lunchtime opens up additional lunch alternatives, thus reducing student use of both the NSLP and school competitive foods and beverages. Having an open campus likely undermines the nutrition objectives of the NSLP, because the foods and beverages bought by students off campus are probably not as nutritious as those served within the NSLP.

To compensate for facility constraints and other issues, some schools have developed “express” versions of the NSLP that provide students with meals more quickly. Similar efforts to serve meals more quickly include “grab and go” breakfasts and breakfasts in the classroom. These alterna-