Background: TV viewing and computer game use may both limit physical activity, but only TV viewing may promote a poorer diet due to exposure to food advertising and availability of the hands for snacking. Purpose: The purpose of this study was to investigate relationships between the different screen times and type 2 diabetes markers among youth. Methods: A sample of 12- to 17-year-olds was obtained from the National Health and Nutrition Examination Survey (NHANES). A mediation analysis was initiated, but the null was retained between the screen time types and oral glucose tolerance test values. Relationships between screen time types and physical activity and diet behaviors were investigated using linear regression and adjustments for multiple comparisons. Results: A one-unit increase in square root-transformed hours spent playing computer games was associated with an increased consumption of 288 calories per day (P = 0.001), whereas TV viewing was not. Discussion: Computer game users might snack more often during pauses in game play or while watching friends play. Understanding more about US adolescents' eating during screen time could help address overeating. Translation to Health Education Practice: If other research corroborates these findings, Health Education professionals should promote physical activity among adolescents directly--instead of discouraging screen time--and promote healthy eating among computer game users.