With strong cardiac rehab experience and expertise in the areas of nutrition, training, and exercise physiology, they aim to provide the best possible support to our Pritikin ICR-licensed facilities from coast-to-coast.

Christina Lewis, MS, RD, LD is a Registered and Licensed Dietitian with over 20 years of experience in clinical dietetics, education, and program management. Prior to joining Pritikin, Christina served in the US Army, and held several positions in clinical nutrition. Most recently, Christina was responsible for education, training, and competencies for Allied Health professionals across 14 hospitals as part of a large healthcare organization in North Texas. Christina is based in the Dallas, Texas, area and proud to be a native of the Lone Star State.

Sharon Mattheisen, RD, LD brings ten years of experience in the fields of nutrition, health, and wellness to our team. Before joining Pritikin ICR, Sharon was the Registered Dietitian for Renown’s Pritikin ICR program in Reno, Nevada, presenting nutrition lectures, teaching Pritikin ICR Cooking School Workshops, and counseling patients one-on-one. Sharon currently lives with her husband and three children in Park City, Utah, where she enjoys trail running, mountain biking, camping, and spending time with her family.

Karyn Panek, MS is an ACSM Certified Clinical Exercise Physiologist with over ten years of direct care in Cardiac Rehab. Karyn received both her BS and MS in Exercise Physiology from the University of Illinois at Chicago. She is a strong advocate of lifestyle medicine and believer that exercise really is medicine. Originally from Chicago, Illinois, Karyn currently lives in Asheville, North Carolina, with her husband and dogs. She enjoys traveling, especially by bike, and thinks there’s no better way to see and experience a new area!