This application responds to RFA-DK-22012, Investigator Award to Support Mentoring of Early Career Researchers from Diverse Backgrounds to provide protected effort and resources to Dr. Gallagher, an established NIDDK-funded investigator and mentor to provide high quality mentoring to graduate students and postdoctoral fellows from diverse backgrounds and underrepresented groups. Dr. Gallagher has extensive experience mentoring fellows and junior faculty, including from underrepresented groups. Her leadership role as MPI in The Physiology of The Weight Reduced State (POWERS) study (5UH3DK128302-03: MPIs Gallagher, Mayer, Leibel, Rosenbaum) provides a rich environment for training with exposure to a diverse array of measures and methodologies. It is well known that obesity is a major contributor to human illness and health care costs. Modest weight loss can mitigate the severity – or entirely reverse - many of these phenotypes. Maintenance of a 7% reduced body in persons, lean and with obesity invokes homeostatic changes in energy expenditure (decreased) and hunger (increased) that tend to restore body weight. We hypothesize that the heterogeneity of response, currently not characterized, accounts for differences in long-term success for reduced weight loss maintenance. POWERS will prospectively interrogate the physiological/behavioral systems that contribute to variability in weight change following weight loss. Healthy adults with obesity will be studied before and immediately after weight loss (Phase 1), and during the follow-up 12 months observational Phase 2. Participants will be extensively phenotyped at 4 timepoints across the 18 months study: weight, body composition, total energy expenditure, energy intake, resting energy expenditure, physical activity, exercise efficiency, sleep quality, food choice, behavioral and psychosocial assessments. POWERS (within the New York Nutrition Obesity Research Center at Columbia) will serve as the framework through which the proposed K24 mentoring and training program will be integrated. Mentoring Aim 1-Research: within the framework of POWERS study, to provide the trainee with exposures and training in the conduct of clinical research involving advanced state-of- the art methods, training in rigor and reproducibility in research, human subject compliance, and scientific manuscript and grant writing; Mentoring Aim 2-Career Development: attend and give research presentations at local and national meeting (eg, ObesityWeek sponsored by The Obesity Society); attendance of seminars for exposure to current research on methodological, biological, psychological, and nutritional aspects of obesity, networking with experts in the related fields, career development, guidance on how to effectively collaborate with researchers from diverse backgrounds and disciplines. My primary training aim as a mentor is to develop skills to be a more culturally aware mentor to optimally mentor early career investigators from diver...