Your Journey Team

Aaron Siegel, MD - Bariatric Surgeon

Dr. Siegel is an independent, board-certified general surgeon with extensive experience in a variety of gastrointestinal operations. He has been performing bariatric surgery at Vista Medical Center East since 2004.

He performs laparoscopic bariatric procedures including gastric bypass, sleeve gastrectomy, adjustable gastric band placement, duodenal switch and SADI-S, as well as revisional operations. He is certified in the use of an intragastric balloon system, a non-surgical weight loss treatment for those with a BMI between 30 and 40. Dr. Siegel is a member of the American Society for Metabolic and Bariatric Surgery. He is the medical director of the bariatric surgery program at Vista Health System.

Janine Pruett, MS, RDN, LDN - Bariatric Coordinator and Dietitian

Janine is a registered and licensed dietitian. As the Bariatric Coordinator, she works collaboratively with the bariatric team, patients, and community to facilitate services and maintain compliance with national accreditation standards for metabolic and bariatric surgery centers. In addition, Janine provides pre and postoperative nutrition assessment and weight management counseling. Janine recognizes there is not a single approach to weight loss and works with each patient individually to help them reach their weight loss goals and improve their quality of life.

Roberta Maller Hartman, PhD - Clinical Psychologist

Dr. Robbie is a licensed clinical psychologist and holds the certification of Professional Certified Coach (PCC) awarded by the International Coach Federation (ICF). Dr. Robbie is an expert on wellness coaching for bariatric patients, focusing on stress management, managing emotional eating issues, and mindfulness training. As part of the bariatric and non-surgical Weight Management Options team, she is responsible for preoperative psychological evaluations. She also leads bariatric support groups, weight management classes, and is available for individual sessions with patients.

Stacey Van Zeyl, MS, EP, ATC - Exercise Physiologist

Stacey is a certified Exercise Physiologist who has been working at Vista for 18 years. She works with bariatric, cardiac and pulmonary rehab patients out of our Lindenhurst location. As part of the Weight Management Options team she does pre-surgery fitness evaluations and consultations to help people start or improve their exercise program: this includes teaching strength, stretching, balance, and aerobic exercises. She also helps people with knee, hip and low back pain learn exercises that will improve their activity level. In addition, she works with bariatric support groups and weight management classes to teach exercise basics and work through barriers to exercise.

* Medical information provided here, in the absence of a visit with a health care professional, must be considered as an educational service only. Patient results may vary. Consult your physician about the benefits and risks of any surgical procedure or treatment.