Dr. Lindsay Jaacks is an Assistant Professor in the Department of Global Health and Population at the Harvard T.H. Chan School of Public Health (HSPH). The unifying theme of the candidate’s research to date is to advance our understanding of the relationship between food systems and obesity and diabetes through the lens of both nutrition and environmental health. Her long-term interest is to establish a multi-disciplinary research group that contributes enduring, high-impact knowledge to our scientific understanding of the etiologies of obesity and diabetes, and to translate that research into interventions to promote public health. The proposed career development plan incorporates a multi-disciplinary program designed to provide an intense, closely mentored research experience in association with a comprehensive structured didactic curriculum in clinical trial design and analysis, and behavioral science. Under the mentorship of Dr. David Christiani (HSPH Dept. of Environmental Health) and Dr. Karen Emmons (HSPH Dept. of Social and Behavioral Science) and with advising from Dr. Antonia Calafat (Centers for Disease Control and Prevention) and faculty at HSPH with expertise in clinical trials, biostatistics, and exposure biomonitoring, Dr. Jaacks will develop a behavioral nutrition intervention for pesticide reduction and test its efficacy in a parallel arm, randomized, controlled feasibility trial. A convenience sample of 120 participants will be randomized 1:1 to receive counseling and support tools for reducing dietary exposure to pesticides (“intervention”) or control. Urine and venous blood samples, height, weight, grocery and restaurant receipts, detailed dietary intake, and questionnaires will be collected at baseline, 3 months, and 6 months. The specific aims are: using an intent-to-treat analysis, determine the effect of the intervention on (1) urinary 3,5,6-trichloro-2-pyridinol concentration, a metabolite of the pesticides, chlorpyrifos and chlorpyrifos methyl (primary outcome) and (2) levels of fasting blood glucose, HbA1c, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, and body weight (secondary outcomes), among a convenience sample of adults living in Greater Boston, as compared to control; and (3) to assess acceptability of the intervention using focus groups (4 total, 2 with ~10 women each and 2 with ~10 men each). In addition to filling important gaps in the candidate’s training, this award aims to translate results from several previous small, controlled feeding studies of short duration to a “real world” setting to establish the impact of exposure reduction on urinary pesticide metabolites and metabolic health. Experience from this feasibility trial will be used to scale up the intervention to a larger, more diverse population, with the ultimate goal of providing actionable targets for addressing environmental risk factors and improving population health.