Joshua Petimar, ScD is a research fellow at the Harvard T.H. Chan School of Public Health who evaluates the effects of public health nutrition policies on diet quality. He primarily uses sales data from food retailers and longitudinal data from large cohort studies to investigate research questions related to calorie labeling, nutrition assistance programs, and effects of the food environment on diet and health. He pursues answers to these policy-relevant questions using natural experiments and epidemiologic methods for causal inference. He received his joint doctorate in Nutrition and Epidemiology from Harvard, where he previously studied relationships between diet, obesity, and cancer.