Project Summary Obesity continues to pose a major public health problem, with approximately one-third of children and adolescents in the U.S. classified as overweight or obese. To combat this crisis, NIH has identified the need for novel research aimed at explicating modifiable factors that contribute to obesity in order to develop cutting-edge, evidence-based prevention and intervention strategies. Informed by theoretical frameworks and methodology from the field of developmental cognitive neuroscience, the proposed project is a response to NIH’s call to action and is comprised of two related studies aimed at investigating the role of executive control (EC; also known as “executive functioning”) in obesity etiology. Defined as a set of critical cognitive abilities responsible for directing attention and other behaviors, EC is a modifiable construct with links to chronic disease risk and health behaviors, including weight problems. However, the literature examining EC and obesity has yet to fully investigate the directionality of the EC-obesity association or appetitive EC, a related construct that may characterize a food specific variant of general EC abilities. Therefore, Study 1 of the proposed project leverages a combination of previously-collected data as well as data from an ongoing NIH-funded longitudinal study of adolescents (N=312) to investigate dynamic, reciprocal associations between EC and body mass index (BMI) across late childhood, pre-adolescence, and adolescence. Study 2 proposes to investigate individual differences in appetitive EC among adolescents (N=70) using a novel fMRI food cue task that teaches participants to regulate their responses to palatable foods. These projects strategically span consecutive developmental periods in order to inform the timing of obesity prevention and intervention strategies. Specifically, clarifying when EC influences obesity in the course of development will inform the timing of interventions, while identifying neural treatment targets will inform behavioral (e.g., inhibition and emotion regulation training) and medical (e.g., screening for neural biomarkers and using personalized interventions for high-risk individuals) strategies for reducing and preventing obesity. The proposed research will take place at the University of Nebraska-Lincoln (UNL), where the applicant is a graduate student in the Clinical Psychology Training Program. The environment at UNL provides state-of- the-art research facilities (including an MRI facility) and is ideally suited for supporting the candidate’s training plan, which was carefully designed to provide training in health behavior assessment, biological factors that contribute to obesity, MRI administration and data analysis, advanced statistical techniques, and grant writing in order to prepare her for a career as an NIH-funded clinical scientist.