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Meet our KADDI Team

Sara Hallgren-Tillery, MA, RD, LD

Sara Hallgren-Tillery, MA, RD, LD is the Program Director. She has spent the last 15 years working as lead clinical dietitian at an academic medical center hospital in Tulsa, OK.  During that time she provided nutrition to diverse groups, organizations and individuals. She has specialized training in neonatal nutrition and child and adolescent weight management.  In addition to excellent patient care, she has used her positive attitude and energy to teach nutrition to medical residents, nurses, ancillary staff, and interns.

Sara loves spending quality time with her family and French Bulldog Molly.  She also enjoys hiking, swimming, crafting, trying new recipes and playing the piano.  

KADDI Program Director 

KADDI & KACAD Founder & Advisor

Patti Landers, PhD, RD, LD, FAND is the Associate Director and Clinical Instructor. Dr. Landers is very experienced and was awarded Professor Emeritus status from the Department of Nutritional Sciences at the University of Oklahoma Health Sciences Center. In 17 years at OUHSC, she served as director of the dietetic internship program as well as the didactic and coordinated programs.

Patti is a native Texan who adopted Ohio, then Arkansas, and now Oklahoma as home. After a career at the University of Oklahoma, she moved to Tulsa and became a consultant dietitian with K&A Nutrition. She is the founding director of KADDI and KACAD and immensely enjoys mentoring dietetic interns and students and working with the other faculty instructors.

Patti Landers, PhD, RD, LD, FAND

KADDI Faculty Instructor

Tiffany Simonson, MS, RD, LD

Tiffany Simonson, MS, RD, LD is excited to be joining the KADDI team this fall as a faculty instructor.  Over her 11 years of working as a dietitian, she has enjoyed working in a variety of roles, such as nutrition sales, nutrition sales management, school nutrition, and foodservice. Prior to becoming a dietitian, Tiffany received a BS in Dance Performance from the University of Central Oklahoma.  She went on to dance professionally around the US and very quickly developed a love for nutrition and training her body for its best performance.  She then hung up her dance shoes and went back to UCO to pursue nutrition and received another Bachelors and eventually her Master of Science in Nutrition.  

Tiffany enjoys traveling and exploring with her husband, 2 kids, and 2 four-legged furry friends.  Her hobbies include running, Barre, and learning how to create our 5 acre homestead.  

KADDI  Faculty Instructor 

Kristen Clifton, MS,RD,LD has enjoyed providing care to patients and residents in a variety of settings over the past 13 years. Kristen received her Bachelor's Degree in Nutrition and Dietetics from Oklahoma State University and her Master's Degree from the University of Central Oklahoma in 2010. She worked as a clinical Dietitian for 2 years before transitioning to consulting in a Long Term Care/Assisted Living setting where she continues to provide care. She married her high school sweetheart and they have 3 children who keep her very busy. Kristen enjoys traveling and exploring new places with her family, reading, gardening and doing any outdoor activity. She is very excited to be joining the KADDI team! 

Kristen Clifton, MS,RD,LD
Crystal Dake KADDI & KACAD Program Assistant

KADDI & KACAD Program Assistant

Crystal has worked for Keith & Associates, Inc. for over 7 years. She started as Sandy Keith’s assistant, managing schedules for over 15 other dietitians across Oklahoma, and handling the office work for over 120 DDSD clients for K&A dietitians. When the internship was created, she became the program assistant. She executes affiliation agreements and handles intern records and onboarding procedures, playing a vital role in the KADDI program.

What Crystal enjoys most is spending time with her daughter.  She loves game night with friends and recently has started new hobbies including composting & bucket gardening! 

KADDI & KACAD Program President

Sandra Keith, MPH, RDN, LD graduated from Baylor University’s dietetic internship and received her master's in public health from the University of Oklahoma. She is the president of Keith & Associates, Inc. which she founded in 1968 to provide consulting services to facilities across Oklahoma. Sandy is also contracted with the State of Oklahoma to provide nutritional services to consumers of the Department of Developmentally Disabled (DDSD) under Oklahoma’s Medicaid Program. Sandy stays active in the Oklahoma Dietetic Association and continues to find ways to give back to the profession.

Sandra Keith, MPH, RDN, LD
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