1. Healthy Eating Research Program, School of Public Health, University of Minnesota, Minneapolis, Minnesota 55454-1015;
2. Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota 55454-1015,
3. Adolescent Health Protection Research Training Program, School of Public Health, University of Minnesota, Minneapolis, Minnesota 55454-1015,
4. Emory Prevention Research Center, Department of Behavioral Sciences and Health Education, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322;