My overall goals are to investigate the role of lifestyle factors, including diet, physical activity and energy balance, in the etiology and prevention of cancer. To meet these goals, my research portfolio includes a variety of observational and intervention studies focused on: 1) improving methods for dietary and physical activity assessment; 2) understanding the extent to which diet and physical activity patterns influence intermediate endpoints or biomarkers that may be on the causal pathway to cancer and; 3) investigating whether adoption or maintenance of specific lifestyle habits will decrease risk of cancer incidence, cancer recurrence or cancer-specific mortality. I focus particularly on breast and prostate cancer.