Our Bariatric Surgery Team
Alexander Morton, MD, FACS
Director of the Denver Health Bariatric Surgery Center
Dr. Morton is the Director of the Denver Health Bariatric Surgery Center. He is an Assistant Professor of Surgery at the University of Colorado School of Medicine and an Associate Program Director for the University of Colorado General Surgery Residency Program.
Originally from Montana, Dr. Morton received his Bachelor of Science from Montana State University, graduating with honors. He received his medical degree and general surgery residency training at the University of Colorado. He also completed a research fellowship in trauma and coagulopathy under the mentorship of Ernest Moore, MD at the University of Colorado Trauma Research Center. Dr. Morton has a strong interest in bariatric and minimally invasive surgery and expanding access to these services to the underserved populations of Denver. His other focus is surgical education and training the next generation of physicians and surgeons through his work with the University of Colorado School of Medicine and General Surgery Residency Program. Outside of work he enjoys spending time with his wife, Ashley, and skiing and hiking in the mountains of Colorado.
Sany Thomas, MBBCH
Bariatric and Minimally Invasive Surgeon
Dr. Thomas is a Bariatric and Minimally Invasive Surgeon and the newest member of the Denver Health Bariatric Surgery Center team. She is an Assistant Professor of Surgery at the University of Colorado School of Medicine.
Dr. Thomas was born and raised in South Africa. She completed medical school at the University of the Witwatersrand in Johannesburg, South Africa. After immigrating to America, she completed general surgery residency at the University of Illinois at Chicago and her Bariatric and Minimally Invasive Surgery fellowship at Scripps Green Hospital in La Jolla, California. She is a board-certified general surgeon and member of numerous national societies including the American College of Surgeons, Society of American Gastrointestinal and Endoscopic Surgeons and the American Society for Metabolic and Bariatric Surgery. Dr. Thomas is excited to bring her expertise to Denver Health and is passionate about improving the patient experience in surgery. In addition to her love of her work, Dr. Thomas is an avid traveler and foodie.
Fredric M. Pieracci, MD, MPH, FACS
Director of Surgery
Dr. Pieracci is the Director of Surgery at Denver Health and former director of the Bariatric Surgery Center. Born in Chicago, Illinois, he received both his Bachelor of Arts degree in biology and his medical degree from the University of Pennsylvania. Dr. Pieracci completed residencies in general surgery and general preventive medicine at the New York Presbyterian Hospital/Weill Cornell Medical College in New York City. During this time, he also obtained a Master’s Degree in Public Health from Columbia University. Additional fellowship training in trauma, acute care surgery and surgical critical care was completed at the University of Colorado and Denver Health. Dr. Pieracci is a Professor of Surgery at the University of Colorado. He is also a past president of the Denver Health Medical Staff. Dr. Pieracci is board certified in general surgery, general preventive medicine and surgical critical care. He is active in many national surgical societies, including the American College of Surgeons, the Surgical Infection Society, the Southwestern Surgical Society and the American Society for Metabolic and Bariatric Surgery.
Dr. Pieracci helped to build and achieve accreditation of the Denver Health Bariatric Surgery Center. He has performed more than 800 bariatric surgeries, published more than 150 peer reviewed articles, and has a deep passion for the life changing benefits of bariatric surgery, as well as the provision of high quality bariatric surgery in underserved communities.
Ann M. Kulungowski, MD, FACS
Director of Adolescent Bariatric Surgery
Dr. Kulungowski is the Director of Adolescent Bariatric Surgery at Denver Health and helped to launch the Adolescent Bariatric Surgery Center in 2022. She is originally from South Texas. She received her Bachelor of Science in biology from the University of the South in Sewanee, Tennessee. Prior to starting medical school, she was a scholar for the Rotary Foundation in Santiago, Chile. Dr. Kulungowski obtained her medical degree from the University of Texas Health Sciences Center at San Antonio. She trained in general surgery, pediatric surgery and surgical critical care through the Department of Surgery and the Division of Pediatric Surgery at the University of Colorado School of Medicine. As part of her training, Dr. Kulungowski was the Jane and Stuart Weitzman Fellow in Vascular Anomalies at Boston Children’s Hospital. She is deeply committed to helping teens – especially those from underserved communities – transform their young lives.
Mollie (Mary) Nardecchia, PA-C, MMSc
Lead Bariatric Advanced Practice Provider
Mollie Nardecchia is a surgical physician assistant with experience in bariatric, thoracic, general, endocrine, colorectal and pediatric surgery subspecialties. She grew up in Spokane, Washington and completed her undergraduate biology degree at the University of Washington in Seattle. Nardecchia earned her Master of Clinical Medical Sciences degree at Barry University in Miami, Florida in 2017. During her physician assistant program in Miami, she worked in several medically underserved communities which especially motivated her love of caring for vulnerable patient populations.
Outside of work, Nardecchia enjoys traveling with her husband and exploring Colorado's beautiful outdoors with their dog, Sydney. Nardecchia has a large family, and after several years of living away from them, she is very happy to be closer to her family in Denver.
Dr. Love-Osborne attended the University of California, Davis for undergraduate (psychology) and medical school, and came to Colorado for pediatric residency and adolescent medicine fellowship. She moved back to Colorado in 1999 and joined Denver Health. Dr. Love-Osborne was one of the pediatric providers who started Denver Health’s Healthy Lifestyle clinic in 2014, serving as a consultant for youth with medical problems related to weight such as prediabetes and non-alcoholic fatty liver disease. As part of the bariatric surgery team, she wants to make sure that patients have all available options to help them live healthy lives. Dr. Love-Osborne’s hobbies include cooking, singing, hiking and skiing. She also volunteers at Demi’s Animal Rescue and fosters cats to help them get adopted.
Dr. Kugelmas is originally from Los Angeles, California and received her Bachelor of Arts from the University of California, Berkeley and her Medical Degree from the University of Southern California. She completed her first two years of pediatric residency at Rainbow Babies and Children’s Hospital in Cleveland, Ohio and then joined her husband at the University of Kentucky in Lexington to complete her third year. After practicing general pediatrics in the Denver area for 15 years, Dr. Kugelmas completed a clinical fellowship in Pediatric Nutrition at Children’s Hospital Colorado. She is board certified in Pediatrics and Obesity Medicine and is an active member of the Obesity Society and the Colorado Obesity Society. Dr. Kugelmas helped develop the Adolescent Bariatric Surgery Center in 2022 and is passionate about helping underserved children and adolescents with obesity improve their health and quality of life. She is fluent in Spanish. When she’s not working she enjoys traveling and exploring new cultures as well as spending time with her husband and three daughters.
Alison Lieberman, PsyD
Clinical Psychologist, Integrated Behavioral Health Consultant
Dr. Lieberman is a Behavioral Health Consultant at Denver Health. She graduated from the University of Denver Graduate School of Professional Psychology. She completed her predoctoral internship in behavioral medicine at the Miami VA Medical Center. She has been at Denver Health since 2005 and is currently working with adults at the Bariatric Surgery Center, Hematology/Oncology clinic, Palliative Care clinic and Women’s Care clinic. She is an instructor at the University of Colorado in the Department of Family Medicine and the Department of Psychiatry at the University of Colorado School of Medicine.
Megan Twomey, PhD
Michelle Darr, RD (in photo - on right)
Registered Dietitian (Adult Bariatrics)
Michelle Darr is a registered dietitian with the Bariatric Surgery Center. She is originally from San Diego, California and received a Bachelor of Science in Clinical Nutrition from the University of California, Davis. After graduating college, she worked in the Food and Nutrition Services department at UC Davis Medical Center and later completed her dietetic internship at UC Davis Medical Center. She then worked for the WIC (Women, Infants, Children) program in Sacramento, California where she loved teaching about early childhood nutrition. Darr relocated to Denver in 2020 and joined Denver Health in early 2021, working with the team as both a full-time and on-call dietitian. Now solely full-time, she is very excited to see patients through the entire surgery process. Darr loves teaching patients about nutrition for bariatric surgery and helping patients overcome barriers to reach their goals. When she isn’t working, she loves to go on long walks with her husband, son and two dogs.
Tara Gray, MS, RD (in photo - on left)
Adult and Adolescent Bariatric Dietitian
Tara Gray obtained her Bachelor of Science degree in Dietetics from Miami University of Ohio in 2015. In 2016, she completed her dietetic internship and received her Master of Science in Medical Dietetics from Saint Louis University. She has been working with the Bariatric Surgery Center since March of 2022 and is passionate about helping patients make healthy, sustainable diet and lifestyle changes. Gray is originally from Columbus, Ohio and moved to Colorado in 2018. Some of her hobbies include hiking, cycling, yoga, cooking, baking and spending time with friends and family.
Tammy Vigil, RD (in photo - in middle)
Registered Dietitian (Adult Bariatrics)
Tammy Vigil obtained her Bachelor of Science in Health Sciences from Rutgers University. She joined Denver Health in 2008 and has been working at the Bariatric Surgery Center since 2014. She enjoys working with bariatric patients and seeing the positive changes that take place in their lives and in their health after surgery.
Leigh Rieder, RN
Leigh Rieder obtained her Bachelor of Science in nursing from North Dakota State University. She joined Denver Health in 1999 and has been working with the Bariatric Surgery Center since 2009. She enjoys working with the bariatric patients and seeing the positive changes that take place in their lives and in their health after bariatric surgery.
Bariatric Administrator and Medical Assistant