Lab Members

Dr. Jonathan Krakoff is the section chief of the Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch and a board-certified endocrinologist and internist. His research investigates the etiology of type 2 diabetes and obesity, primarily by focusing on issues that affect energy balance, energy expenditure, and energy intake.

Dr. Douglas Chang is Medical Director of the Clinical Research Unit in the Obesity and Diabetes Clinical Research Section of NIDDK Phoenix.  Dr. Chang is board certified in both Internal Medicine and Obesity Medicine.  Current research interests include understanding determinants of energy intake and expenditure with a special emphasis on examining the interaction between hydration and obesity which is characterized by prolonged energy imbalance. Additional research examines the role of insulin and glucose regulation in metabolism and investigates novel biomarkers of type 2 diabetes.

Dr. Marci Gluck is Director of Behavioral Sciences in the Obesity and Diabetes Clinical Research section of the NIDDK. She is a trained clinical health psychologist, having completed her graduate training from the Albert Einstein College of Medicine from Yeshiva University, her predoctoral internship at Yale University School of Medicine, and her NIH postdoctoral fellowship at Columbia University College of Physicians and Surgeons. Dr. Gluck has over 20 years of experience conducting clinical studies in adults with obesity and disordered eating behaviors. Her research focuses on the integration of behavioral, neuropsychological and physiological mechanisms that influence appetitive behavior and body weight regulation.  In her spare time, Dr. Gluck enjoys hiking, spending time with her two dogs Ben & Jerry and complaining about the Arizona heat!

Dr. Votruba has a Ph.D. in Nutritional Sciences and is a Registered Dietitian. She is the only R.D./Ph.D. at NIDDK PECRB, and is responsible for the oversight of the metabolic kitchen and also functions as a PI on several studies. Her research interests include improving measurement of food intake and establishing determinants of weight loss and gain. Her broader research interests are in the metabolic determinants of obesity, obesity phenotypes, the measurement of food intake, the development of biomarkers of food intake, and the interaction of the microbiome with the physiology of metabolism.

Tomás Cabeza de Baca, Ph.D., is an associate scientist for the Obesity and Diabetes Clinical Research Section in Phoenix, Arizona. He received his doctoral degree from the University of Arizona and completed his postdoctoral training at the University of California, San Francisco. His research interests include the examination of psychosocial, ecological, and physiological determinants of energy intake and expenditure and their underlying effects on cardiometabolic risk and physiological deterioration. In his spare time, Tommy enjoys shortening his telomeres with cheeseburgers and tequila.

Paolo Piaggi, Ph.D. is interested in the physiological and genetic determinants of the energy balance equation (energy intake and expenditure) and the role these play in contributing to weight change and in predisposing individuals to obesity.

Emma J. Stinson, M.P.H. is a statistician for the Obesity and Diabetes Clinical Research Section in Phoenix, Arizona. She received her master’s degree in Biostatistics from Drexel University in March of 2020. Her research interests include the development and application of statistical methodology in the study of obesity and eating behaviors with an emphasis on the psychosocial and behavioral determinants of energy intake and energy expenditure.

Beyza Aydin, M.D., is a visiting fellow in the Obesity and Diabetes Clinical Research Section in Phoenix, Arizona. She earned her M.D. from Istanbul University, Istanbul Faculty of Medicine, Turkey, in 2019. She practiced as a physician in an emergency department in Turkey for two years. Beyza's primary research focuses on the effects of gallbladder disease and cholecystectomy on spontaneous physical activity, 24-hour energy expenditure, and substrate oxidation, measured in an indirect calorimetry metabolic chamber. She is also interested in studying t-DCS brain stimulation as a potential mediator of weight loss and its long-term effects on caloric intake.

Manuel Dote Montero, Ph.D., is a visiting fellow at the Obesity and Diabetes Clinical Research Section in Phoenix, Arizona. He received his doctoral degree from the University of Granada, Spain. His research focuses on elucidating the physiological mechanisms controlling energy balance, including both energy intake and expenditure. His work aims to uncover the roles these mechanisms play in weight fluctuation and obesity susceptibility. Ultimately, he strives to develop innovative and effective interventions for obesity treatment.

Keizer is a post bac IRTA fellow working in the Obesity and Diabetes Clinical Research Section. He graduated with degrees in Biology and Spanish from Northern Arizona University in Spring 2021. Prior to his current position, he worked as a medical scribe for a bariatric surgeon. This sparked his initial interest in research regarding weight loss, metabolism, and energy expenditure. After completing his fellowship, Keizer plans to attend medical school and is interested in primary care. In his free time, he likes to explore the Phoenix metro area’s restaurants and cafes during the winter and immerse himself in a new fantasy book during the summer.

Ashley is a post bac IRTA working in the Obesity and Diabetes Clinical Research Section. She graduated with her B.S. in Psychological Sciences from Northern Arizona University in May 2024. Prior to her current position, Ashley engaged in health disparity research at Northern Arizona University and National Institute of Neurological Disorder & Stroke. Ultimately, she strives to become a health care provider/scientist for her community. In her free time, she loves going back to the rez & spending time with family.