Inadequate sleep has been associated with increased adiposity and BMI among adolescents . Lack of sleep may influence dietary behaviors. The aim of this study is to determine the association between sleep , and dietary habits and exercise among adolescents . In this cross-sectional study, 581 adolescents (47% males) ages 11-19 years from 10 selected middle and high schools in Southern California and Michigan completed an online survey, which included a food frequency questionnaire and questions on lifestyle and sleep habits . Anthropometric measurements were taken during school visits. Data was analyzed using descriptives, t-tests, ANOVA and χ 2 with adjustment for relevant confounders. Physical activity was significantly associated with sleep duration (p=0.0431). Subjects who slept less than 8-9 hours per night were more likely to exercise 蠅90 minutes per week compared to those who slept <8 or >9 hours. Sleep duration was significantly associated with breakfast consumption (p<0.0001). 74% of those who slept >9 hours always ate breakfast compared to 61% and 41% of those who slept for 8-9 hours and <8 hours, respectively. Sleep duration was significantly associated with snack consumption after dinner in male subjects (p=0.035). Male subjects who slept 8-9 hours were less likely to eat a snack after bedtime compared with those who slept <8 hours or >9 hours. Bedtime was significantly associated with type of lunch eaten (p=0.02). Students who went to bed after 9 pm were less likely to consume a convenience lunch (fast food or store-bought) when compared to those who went to bed before nine. Sleeping patterns are associated with physical activity and dietary habits , which may have implications in weight management.