Department of Community Health Sciences, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA, United States. Electronic address: maywang@g.ucla.edu. Department of Biostatistics, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA, United States. Department of Community Health Sciences, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA, United States. Evaluation Consultant, Los Angeles, CA, United States. Nutrition Policy Institute, University of California, Berkeley, CA, United States. Division of Chronic Disease and Injury Prevention, Los Angeles County Department of Public Health, Los Angeles, CA, United States. Abt Associates, Cambridge, MA, United States. Kaiser Permanente Southern California Community Benefit, Pasadena, CA, United States. Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health, Seattle, WA, United States. Public Health Foundation Enterprises-Special Supplemental Nutrition Program for Women, Infants and Children (PHFE-WIC), Irwindale, CA, United States.