Our Bariatric Surgeons

Dr. Robin Blackstone, MD

Robin Blackstone MD, FACS, FASMBS

Medical Director, HonorHealth Bariatric Center

Dr. Blackstone is one of the few women surgeons in the world specializing in the Laparoscopic Gastric Bypass Surgery. With her practice focused entirely on weight loss surgery, she is committed to providing patients with the very best care possible.

From a fourth generation Arizona family, Dr. Blackstone grew up in the Grand Canyon National Park. She attended the University of Arizona in Tucson after high school and graduated with a Bachelor's degree in Philosophy. After being accepted as a medical student at the University of Texas in San Antonio, she graduated and received her Doctor of Medicine in 1988. Dr. Blackstone then completed her General Surgery residency at the University of Colorado, graduating in 1993 as a general surgeon specializing in the leading-edge field of advanced laparoscopic surgery.

Read more on Dr. Robin Blackstone


Dr. Jason Reynoso, MD

Jason Reynoso, MD, FACS

HonorHealth Bariatric Center

Prior to joining the HonorHealth Bariatric Center, Dr. Reynoso held appointments as Clinical Attending General Surgery at the VA Medical Center in Omaha and Research Associate at the Center for Advanced Surgical Technology at the University of Nebraska Medical Center.

A graduate of Arizona State University, he earned his Doctor of Medicine from the Creighton University School of Medicine in Omaha, Neb. Dr. Reynoso then returned to Arizona, serving progressively as intern, resident and chief resident of general surgery at the University of Arizona College of Medicine. While there, he was honored with the General Surgery Residency Program’s Wendell B. Whitacre MD Outstanding Chief Resident Award.

Following his residency, Dr. Reynoso completed a fellowship in advanced minimally invasive surgery at the University of Nebraska Medical Center.

Read more on Dr. Jason Reynoso

Dr. Reynoso in the News

Obesity: A weighty problem

I’m obese, but when I lose weight, I gain it back and more. Why?


Dr. James Swain, MD

James Swain, MD, FACS, FASMBS

HonorHealth Bariatric Center

Prior to joining the HonorHealth Bariatric Center, Dr. Swain served as Director of Bariatric Surgery at the Mayo Clinic in Rochester, Minnesota and Assistant Professor of Surgery at the Mayo Clinic College of Medicine. Board-certified by the American Board of Surgery, his areas of specialty include minimally invasive surgery, bariatric surgery, anti-reflux and general surgery.

After graduating from Wichita State University, Dr. Swain received his medical degree from the University of Kansas School of Medicine in Kansas City. He then completed his residency in general surgery at the Mayo Clinic in Scottsdale, Arizona, during which he was awarded the Society of Laparoendoscopic Surgeons Laparoendoscopic Resident Achievement Award. Following his residency, Dr. Swain completed a fellowship in minimally invasive surgery at the Mayo Clinic in Jacksonville, Florida.

Read more on Dr. James Swain


Our Bariatric Coordinator

Tammi Burns, ANP - Bariatric Program Coordinator

Tammi Burns, RN, MSN, FNP

Tammi Burns is excited to be a part of HonorHealth Bariatric Center as the Bariatric Program Coordinator. She has a Master’s degree in nursing and is a Family Nurse Practitioner.

Tammi has previously worked as nurse practice consultant with the Arizona State Board of Nursing and was a nurse manager of two surgical units at a hospital in Tucson. In her current position as Bariatric Program Coordinator, she is responsible for overseeing and managing the operations of the bariatric program. This includes coordination of care for patients; patient and staff education; oversight of on-going bariatric surgery Center of Excellence compliance and acts as a liaison between hospital and surgical practice. She is inspired by the patients’ successful weight loss and improved quality of life after bariatric surgery and looks forward to being additional support to every one of you. Outside of work, she enjoys traveling and spending time with her family. Tammi can be reached at 480-882-7443.


Our Bariatric Nurse Practitioners

Marcia Cunningham, MSN, CWCN, FNP-C

Marcia Cunningham, MSN, CWCN, FNP-C

HonorHealth Bariatric Center is proud to introduce the newest addition to its medical staff, Marcia Cunningham. Marcia is a Family Nurse Practitioner and is certified by the American Academy of Nurse Practioners (FNP-C) as well as a Certified Wound Care Nurse (CWCN).

Marcia began her career as a Registered Nurse in ICU and was also a captain in the Air Force. Marcia’s other previous clinical experiences includes occupational health and wound care. Marcia has been an RN for over 20 years and has worked in a variety of settings, most recently she worked as a Nurse Practitioner for two years at a primary care clinic.

Read more on Marcia Cunningham, FNP


Melissa Davis, DNP

Melissa Davis, DNP, MSN, ANP-C, CNS, CNOR, RNFA

Melissa is a board certified nurse practitioner (ANP-BC), clinical nurse specialist (CNS), and assistant in surgery (RNFA). She earned her BSN from Seton Hall University and post-master’s nurse practitioner from Saint Louis University. Most recently, she earned a doctorate in nursing practice (DNP) from Northern Arizona University, where her project “Transparency and Advanced Practice Nurse Value on an Interprofessional Team by Time-Driven Activity-Based Costing” was awarded “best doctoral project” by the school of nursing faculty.

Melissa has been caring for bariatric medical and surgical patients since 2001 when she joined Dr. Robin Blackstone at the Scottsdale Bariatric Center, which, in 2010, became HonorHealth Bariatric Center. Melissa truly loves everything about her position as an advanced practice nurse, including assisting Dr. Robin Blackstone on all surgical cases, hospital rounding, clinic exams, education, and research. 

Read more on Melissa Davis, DNP


Our Registered Dietitians

Bebe Brown, RD, MAEd - Our Registered Dietician

Bebe Brown, MAED, RD

Bebe Brown received her Bachelor’s degree in Nutrition from the University of Montevallo, just outside of Birmingham, AL. She completed her supervised dietetic internship program as well as her Masters in Health Education at the University of Alabama/Birmingham. Bebe then had the opportunity to live in Kampala, Uganda where she taught and supervised third and fourth year university students in nutrition-related courses. She moved back to the Valley of the Sun shortly after the birth of her daughter in 2006 and has worked at HonorHealth ever since. She has been employed as both an inpatient and outpatient dietitian counseling both children and adults in various areas of nutrition including but not limited to, weight management, food allergies, liver disease and diabetes. In her spare time, Bebe enjoys traveling, reading, pilates and spending time with her husband and 6 year old daughter.


Samantha Easterly, RD

Samantha Easterly, RD, CWC

Samantha Easterly received her Bachelor’s degree in Nutrition from Arizona State University in 2003. She completed a supervised dietetic internship program through the Maricopa County Department of Public Health. After completing her internship, she received her Certificate of Training in Adult and Childhood Weight Management through the Academy of Nutrition and Dietetics and has also become a Certified Wellness and Health Coach. Currently, she is a member of ASMBS (American Society for Metabolic and Bariatric Surgery), OAC (Obesity Action Coalition), and The Academy of Nutrition and Dietetics.

Mrs. Easterly has been a Registered Dietician Educator at HonorHealth Bariatric Center since 2005. 

Read more on Samantha Easterly, RD


Our Exercise Physiologists

Arrin Larson BS

Arrin Larson, BS, NSCA-CPT, CWC

Arrin believes fitness begins right now! She understands physical and emotional factors can lead people to exercise or not. She is devoted to assisting you in finding joy and satisfaction in movement and in life. She will help you break through your barriers and take charge with a plan you can live with!

Arrin is an exercise specialist and wellness coach. Her broad scope of practice includes expertise in the areas of arthritis, osteoporosis, fibromyalgia, chronic fatigue and other health related issues. With over 10 years of experience she has helped thousands of individuals to experience physical and mental transformation.

Read more on Arrin Larson, BS


Dorrie Wilson BS

Dorrie Wilson, BS, ACE, CWC

Dorrie Wilson received her Bachelor’s of Interdisciplinary Studies Degree, with concentrations in Exercise and Wellness and Sociology, from Arizona State University. Dorrie holds her Personal Training certification from the American Council on Exercise (ACE-PT) and is a certified Wellcoach (Wellcoaches Corporation). Dorrie has a true passion for motivating people to feel confident with themselves when it comes to movement and exercise. She finds great fulfillment working with the Bariatric patient and encouraging them through their surgical process and life changes. She has been part of the HonorHealth Weight Management team and Scottsdale Bariatric Center team since April of 2005. Here she is finding incredible gratification working with all the patients and employees.

Dorrie is available for personal training, wellness evaluations, and wellness coaching.


Our Clinical Psychologists

Dave Engstrom, PhD

Dave Engstrom, PhD, ABPP

David Engstrom, Ph.D. is a Clinical Health Psychologist with over 10 years of experience with bariatric surgery patients in California and Arizona. He received his A.B. degree in Psychology from The George Washington University and earned his Ph.D. from The University of Southern California. He served his Internship at L.A. County-USC Medical Center and has relocated to Scottsdale six years ago. He is Board Certified in Clinical Psychology and works closely with HonorHealth Bariatric Center, where his offices are located. Dr. Engstrom has authored many publications in health psychology and has an active schedule of public speaking. He has presented papers at the American Society for Metabolic and Bariatric Surgery and contributed to articles in their journal. In addition to his passion for helping people with weight management, his other primary interests are motivational coaching, stress management and sleep disorders. In his spare time, he enjoys spending time with family, hiking, running, fly fishing, African hand drumming and Tai-Chi.


Buddy Messer PsyD

Buddy Messer, PsyD

Buddy Messer, Psy.D. is a Clinical Psychologist who has worked closely with bariatric patients for the last 13 years. He has provided assessment and clinical support at HonorHealth since 2003. Buddy earned his Doctorate in Clinical Psychology from Biola University and has practiced in Arizona throughout his professional career. Over the last decade with HonorHealth Bariatric Center, he has participated in research and presented talks at several national conferences of the American Society for Metabolic and Bariatric Surgery. In addition to his work with HonorHealth, he also works with individuals and families impacted by serious mental illness in Arizona. He actively serves on professional panels working to improve the state of mental healthcare in the state. Buddy has a wife and three beautiful daughters who are the light of his life


Free Bariatric Surgery Seminar

Learn everything you need to know about obesity and how to get the help you deserve.

  • What causes obesity both genetically and environmentally?

  • What other health risks (called co-morbidities) does obesity pose?

  • What are your obesity treatment options and how do each of them work?

  • What are the chances of success for each type of treatment?

  • What are the risks associated with with each type of treatment?

  • How long will you be in the hospital?

  • When will you be back to work?

  • What are the costs involved?  Is it covered by insurance or Medicare?

  • What makes HonorHealth Bariatric Center the best place to have my weight loss surgery?

Get answers to these and many more questions today. Attend our free seminar on weight loss surgery options.