Marina R Sweeney1, Katie M Applebaum2, Hannah Arem1, Barbara H Braffett1,3, Jenny N Poynter4, Kim Robien5,6. 1. Department of Epidemiology and Biostatistics, Milken Institute School of Public Health, George Washington University, Washington, D.C. 2. Department of Environmental and Occupational Health, Milken Institute School of Public Health, George Washington University, Washington D.C. 3. Biostatistics Center, George Washington University, Rockville, Maryland. 4. Division of Epidemiology and Clinical Research, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota. 5. Department of Epidemiology and Biostatistics, Milken Institute School of Public Health, George Washington University, Washington, D.C. krobien@gwu.edu. 6. Department of Exercise and Nutrition Sciences, Milken Institute School of Public Health, George Washington University, Washington, D.C.