Our Providers

Michael Schuhknecht, DO

“I enjoy seeing the positive changes in my patients’ lives throughout their weight loss journeys. Their outlooks improve and they become more active. That’s the real joy my job brings to me – helping people get back to living life.”

Dr. Schuhknecht is one of Michigan’s most experienced bariatric surgeons, having performed procedures for nearly 20 years. During his career he served as chief of surgery at St. John Detroit Riverview Hospital and assistant program director of General Surgery for the St. John Detroit Riverview Hospital Medical Education Department. He is board-certified by the American Osteopathic Association (AOA) Board of Surgery, a Fellow of the American College of Osteopathic Surgeons (FACOS) and member of the American Society of Metabolic and Bariatric Surgeons.

Teri Peak, DNP, FNP

“It’s a privilege to develop a relationship and care for each of our patients throughout their weight loss journey. I find it particularly rewarding when they are able to reach a healthy place in their life and resolve co-morbidities they once faced.”

Teri Peak has been a nurse practitioner since 2005 and began her career at the Lakeland Comprehensive Weight Loss Center in 2010. In 2016, she earned a Doctor of Nursing Practice degree from Frontier Nursing University. Her research focused on shared medical appointments for bariatric patients prior to surgery – an idea she has begun to implement within the center.

Debora Tenter, NP

Debora earned her Master of Science in Nursing degree from Maryville University, located in St. Louis, Missouri. She graduated in the winter of 2015 with a focus in family medicine. For the last 27 years, Debora has been caring for patients locally as a registered nurse at Lakeland Medical Center, in St. Joseph. She has experience in the emergency department, critical care, and cardiology.

Jamie Birris, PsyD

“Every patient deserves personalized, compassionate care and the best opportunity to be successful in their weight loss and health goals. That is what I strive for with each of my patients.”

Dr. Birris will provide evidence based treatments to address psychological factors which may impact weight loss and health, both before and after surgery. Prior to working at Lakeland she worked as an Assistant Professor in the Department of Psychiatry and Behavioral Neurosciences at Loyola University Medical Center in Maywood, Illinois. Dr. Birris earned both her Master’s degree and a Doctoral degree in Clinical Psychology at the Chicago School of Professional Psychology and is a member of the American Psychological Association.

Marcia Wiinamaki, PsyD

“One of the best things that I really enjoy, is helping them get back on a better path to help them experience and realize the dreams that they had for their life.”

Dr. Wiinamaki has been practicing as a Therapist since 1988, and she received her Doctor of Psychology degree from George Fox University in Newberg, Oregon. Her experience as a therapist includes working with issues such as depression, anxiety, childhood sexual and physical abuse, premarital and marital therapy, family therapy, relationship problems, group psychotherapy, adjustment issues, psychiatric medications, divorce mediation and coaching services, and clinical supervision, as well as evaluations for surgical procedures.

Heather Collins, RD

“I have had a lifelong passion for health and nutrition. It is very rewarding to create long-lasting relationships while helping individuals better their lives through nutrition.”

Heather is a registered dietitian who is also board-certified in obesity and weight management. She completed her Bachelor’s Degree in the Science of Nutrition and Dietetics at Andrews University in Berrien Springs, Michigan, and an additional post-graduate internship in conjunction with Lakeland Health. She is a member of the Academy of Nutrition and Dietetics and an associate member of the American Society for Metabolic and Bariatric Surgery. She has been caring for patients at the Lakeland Comprehensive Weight Loss Center since 2015. Heather has been instrumental in developing the curriculum for, and facilitates the shared medical appointments.

Robin Hebard, RD

“I had the opportunity in a previous position to co-create a postpartum weight loss program for women that had just given birth. Through this experience, I knew that weight management and bariatric surgery was where I wanted to specialize. I love being a part of our patients' emotional and physical transformations, as they go through their journey!”

Robin is a registered dietitian who is also board-certified in obesity and weight management. She completed a Bachelor’s Degree in the Science of Nutrition and Dietetics through Andrews University in Berrien Springs, Michigan. She also finished a post-graduate internship at Indiana University (IU) Goshen Hospital. Robin is a member of the Academy of Nutrition and Dietetics, the Weight Management Dietetic Practice Group, and an associate member of the American Society for Metabolic and Bariatric Surgery. She has been caring for patients at the Lakeland Comprehensive Weight Loss Center since 2015.