Our Orange County Weight Loss Surgery Team

Allison Merriman, MMSc, PA-C

Physician Assistant, Clinical Program Director
Allison is a board certified Physician Assistant who completed her medical education and training at Yale University School of Medicine in New Haven, Connecticut. She has been in practice since 2002. Allison also holds a bachelors degree in exercise science from Western Washington University. She has been involved with weight loss surgery for many years. Allison has completed and published research in the field of bariatrics and is an active member of the American Society for Metabolic and Bariatric Surgery.

Kay Phoenix Tran, M.S., PA-C

Physician Assistant
Kay earned her Master of Science in Physician Assistant Studies at Western University of Health Sciences and her undergraduate degree at University of California, Irvine. She has a background in vascular surgery practicing in the East Bay. She assists in surgery and is very involved in clinical perioperative care. She strives to give superior patient care. Outside of work she enjoys the gym and the outdoors.

Danielle Garcia, Psy.D

Psychologist
Dr. Danielle Garcia is a California licensed clinical psychologist who completed her doctoral degree in psychology at Rosemead School of Psychology in La Mirada. Dr. Garcia performs psychological evaluations before surgery and provides psychological support as needed after surgery. She is also a frequent moderator at our support group meetings. Her dedication to helping patients through the entire weight loss process makes her an indispensable member of the team. When she is not working, Danielle loves spending time with her husband and three young children.

Alexandra Mark, MS, RD

Registered Dietitian
Alexandra earned her Bachelor’s degree in Psychology from Columbia University. She later enrolled at Florida International University where she received a Master of Science degree in Dietetics & Nutrition. Alexandra is a Registered Dietitian, an active member of the American Dietetic Association, the California Dietetic Association, and The Sports, Cardiovascular and Wellness Nutrition Practice Group. She is an avid runner and enjoys competing in local races.

Jennifer Oliak, CPA

Practice Director
As our Director, Jennifer oversees the business side of the Practice. With quality health care and premier customer service as our main priorities, Jennifer's goals are continual growth and development of the Practice. She is a CPA with 8 years experience in Health Care Management. Prior to her role at the Oliak Center, Jennifer was a VP in Corporate Restructuring at Ernst & Young. She holds a Bachelors of Science degree from the University of Maryland where she graduated with Magna Cum Laude distinction. Jennifer has completed coursework toward her MBA at UCLA's Anderson School of Business.

Lorraine Tiffany-Malone, MS

Practice Manager
Lorraine Tiffany-Malone, M.S. is a graduate of UCLA with a master’s degree in Physiological Sciences.  For over 20 years, she was employed in a variety of capacities for the Pritikin Longevity Center in Santa Monica.   Lorraine served as the Director of a large bariatric surgical practice with Michigan Medical Physician’s Corporation.   Most recently, she was a Medical Practice Manager at Helen DeVos Children’s Hospital in Michigan.  Lorraine sings soprano in a local church choir, raises Kuvasz dogs (Brando and Denali), and drives sports cars with her husband Bob. 

Melanie Santos

Senior Patient Coordinator
Melanie obtained her Bachelors of Science degree in biological sciences from the University of California, Irvine. She has been in the medical field since 2005 and has extensive knowledge regarding insurance approvals and protocols. She is always willing to answer your questions as she guides you through the entire process to surgery. Melanie is passionate about health and nutrition and is continuing her education in this field. She currently hosts a healthy cooking class as part of our support group program.

Esmeralda Cruz

Medical Assistant
Esmeralda is a certified Medical Assistant who graduated in 2009 from Newbridge Collge in Santa Ana. She enjoys working at the Oliak Center for Weight Loss, and is always willing to learn new things to improve her career. Esmeralda strives to provide excellent customer service, and in her spare time, she enjoys exercising and spending time with her friends and family.

Katie Heyman

Administrative Assistant
Prior to becoming the newest member at the Oliak center, Katie worked for a number of years as a radiology assistant for a multi-physician practice. She is very excited to be a part of the team and eager to contribute. Katie believes it is important to keep both the body and the mind active. She loves books and crossword puzzles, and likes to spend time at the batting cages, and the driving range. She is currently pursuing a degree in psychology and hopes to one day become a clinical psychologist.