Our Company

Nutrition Therapy Associates, Inc. (NTA) has been serving San Antonio, Texas since 1995.  We are a group of Registered and Licensed Dietitians that provide nutrition counseling and consulting services for adults and children throughout south-central Texas.  
Our mission is to help individuals improve their health through optimal nutrition and physical fitness.  We can help you with a variety of concerns including weight management, diabetes, cholesterol managements, nutrition during pregnancy, pediatric nutrition, or simply healthy eating.  

Christy Frantz, 
Owner & President
Christy Frantz is Owner and President of Nutrition Therapy Associates, Inc. and is a Registered and Licensed Dietitian in the San Antonio/Hill Country area.  While she specializes in pediatric nutrition, she is trained to help people of all ages, backgrounds, and nutrition needs to ensure health and wellness through optimal nutrition.  Christy will work with you to achieve your health and nutrition goals.  
Christy is a graduate of Texas A&M University where she majored in nutritional sciences.  She completed her supervised dietetic internship at the University of Medicine & Dentistry in New Jersey.  Christy has worked in association with the Food Stamp Nutrition Education Program and Expanded Food & Nutrition Education Program of New Jersey providing nutrition education lessons for low literacy, low income, urban individuals.  She has also worked at the Children's Hospital of Philadelphia (CHOP) specializing in the ketogenic diet.  During her time at CHOP, Christy contributed to the Ketogenic Diet Manual for the Children's Hospital of Philadelphia, along with the addition of a recipe book helping families prepare innovative meals for this difficult and specialized diet.  Her career with NTA began in 2012 as a consultant serving the Early Childhood Intervention Program in the Hill Country area along with consulting families at the Kendall County Head Start Program.  She has also been involved in heading up the nutrition program, Any Body Can, for the San Antonio non-profit organization, Any Baby Can.  Christy now owns and operates NTA and aims to continue to improve the nutrition status of San Antonio and the surrounding Hill Country areas.  

When Christy is not working, she enjoys spending time with her husband and two children.  She also enjoys running, hiking, swimming, scrapbooking, and catching up with friends.       
Christy belongs to the following professional organizations: 

American Academy of Nutrition and Dietetics
Texas Academy of Nutrition and Dietetics
San Antonio Academy of Nutrition and Dietetics

Pediatric Nutrition Practice Group

                                     
Christy's Publications:
Since starting her career, she has been involved with the following publications:

Brenda Waber, RD, CSP, CNSD, LDN, Colleen Yanni, MS, RD, LDN, Maria R. Mascarenhas, MBBS, and the CHOP Committee of Dietitians.  The Philadelphia Guide Inpatient Pediatrics.  Malden, Massachusetts: Blackwell Publishing; 2005: 287-295.

Complications in Managing Type I Diabetes Mellitus in a Patient with Pyruvate Dehydrogenase Deficiency: Henwood, MJ, Grimberg A, Thornton P, Preis C, Younkin D, Frantz CL; Poster presentation at Endocrine Society Meeting, June 2003.

Monitoring the Ketogenic Diet – Is there a standard?; Christy L. Frantz, RD, LD, Claire M. Chee, RN, AG Christina Bergqvist, MD; Poster presentation at American Epilepsy Society Conference, December 2002.

Reed DB, Bielamowicz MK, Frantz CL, Rodriguez MF.  Clueless in the Mall: A Website on Calcium for Teens.  Journal of the American Dietetic Association. 2002 Mar;102(3 Suppl):S73-6.

An Examination of Food Safety Practices at Day Care Centers that are Member Agencies of the Community Food Bank of New Jersey: An observation of food handling equipment, storage, and practices in a selected sub-sample of child care centers; C Frantz, S Kassirer, C Lopez, K Miller, S Wilson, D Langevin, MS, RD, C Kwiatkowski, MS, RD, CNSD, G McKay, M.Ed., RD; Poster presentation at NJDA Annual Conference, June 2001.

The NTA Team:
NTA currently utilizes the expertise of six additional dietitians to meet a variety of needs our clients may require.  No matter your nutrition need, contact us to see how we can help.  

Join Our Team:  If you are an organized, high energy self-motivated Registered Dietitian, desire to be your own boss, and looking for flexible hours...Nutrition Therapy Associates might be the right place for you.  Email your resume and a brief message on why you want to join our team.  
Meet the NTA Dietitians:

Tirza Nestel, RDE
Registered Dietitian 

Tirza has specialized in pediatric nutrition for over 15 years and provides nutrition education to parents of children with growth and development disorders, including autism, obesity, growth failure, behavioral feeding problems and food allergies. She received her Bachelors of Science degree as well as completed her Dietetic internship training at The University of The Incarnate Word. She is a member of The Academy of Nutrition and Dietetics, Texas Academy of Nutrition and Dietetics and The San Antonio Academy of Nutrition and Dietetics. Tirza enjoys public speaking and has presented multiple workshops/lectures on healthy living.

Tirza has a true passion for the field of nutrition and dietetics and her mission is to inspire others to try new foods and make healthy eating fun and delicious.
Lorie Casanova-Guizar, RD, LD
Registered Dietitian

I have been a practicing RD since May 2001 and working with NTA since Feb 2006.  I truly love working as a Registered Dietitian.  My specialties range from pediatrics to geriatrics and include certification in weight management for children and adolescents.  I also have 5 years’ experience in diabetes management and End stage renal disease with hemodialysis patients. NTA is a wonderful company to work for, because I am able to visit clients in their home to assist them with a variety of nutrition needs they may have.  I enjoy knowing that I am making a difference in someone’s life in a small way.  Thanks to NTA, I am able to make a small difference in many little ones lives.
Vanessa Estrada, RD, LD
Registered Dietitian
Christine Collymore RD, LD, CSP, CNSC
Registered Dietitian
Jennifer Thornton, MS, RD, LD
Registered Dietitian

Jessica Acosta MS, RD, LD
Registered Dietitian