Dietetics Dictionary: Advanced Certifications

Once you become a Registered Dietitian, there are many advanced certifications you might want to pursue. Maybe you’ve seen lots of letters after the names of experienced dietitians and wondered what they are. These certifications can help you show your experience and expertise or allow you to learn new skills. Knowing the meaning of these acronyms for advanced certifications also helps you know more about the RDs you meet in the field!

Looking for definitions of other terms in the field? Check out our Dietetics Dictionary: Basics of the Field!

RDN-AP – Advanced Practice Registered Dietitian Nutritionist

Advanced Practice Registered Dietitians are professionals with a high level of experience and knowledge in the field of dietetics. Candidates must have at least four years of experience as an RD and documentation of 2,000 clinical hours. Additionally, they must have at least one of the following: a graduate degree, presentation of practice topics and/or research, publication in a peer-reviewed journal or clinical nutrition book, or a specialist certification. Candidates must then pass an exam that covers in-depth knowledge of the nutrition care process.

CNSC – Certified Nutrition Support Clinician

The CNSC credential designates health professionals who have advanced knowledge of nutrition support (meaning enteral and parenteral nutrition – a.k.a. feeding tubes). This credential is granted by the National Board of Nutrition Support Certification (NBNSC), which was by the American Society for Parenteral and Enteral Nutrition (ASPEN). The CNSC is not exclusive to RDs: nurses, doctors, pharmacists, and physician assistants all qualify. Candidates are encouraged to have at least two years of experience, but it is not required. Candidates must pass an exam to qualify as a CNSC.

CSOWM – Certified Specialist in Obesity and Weight Management

The CSOWM credential is administered by the Commission on Dietetic Registration but is not limited to registered dietitians. Advanced practice registered nurses, exercise physiologists, licensed clinical psychologists, licensed clinical social workers, pharmacists, physical therapists, and physician assistants are also eligible to become CSOWMs. The exam covers physical assessment related to overweight and obesity, considerations for counseling and behavior change, and types of interventions for weight loss and weight management.


The following CSG, CSPCC, CSP, CSO, CSR, and CSSD credentials are all administered by the Commission on Dietetic Registration (CDR). All of these certifications require a minimum of two years of experience post-RD-exam and documentation of 2,000 of practice hours related to the specialty. ( Certain types of advanced education or professional work may substitute for some of the required practice hours – see the eligibility requirements. Each certification also requires its own exam. More information can be found via the links in each description.

CSG – Certified Specialist in Gerontological Nutrition

The CSG certification recognizes dietitians who have advanced knowledge of nutrition for elderly patients. The exam content has special emphasis geriatric nutrition assessment, inclusion of caregivers in nutrition education, management of supplements, palliative care, and food safety.

CSP – Certified Specialist in Pediatrics

The CSP credential focuses on the nutrition care of all children, whether they are sick or healthy, in all settings. The exam covers a wide range of clinical knowledge for all stages of life from birth to age 18. Topics include anthropometric measurements specific to children, signs of nutrition-related problems in children, and coordination of care outside the clinical setting.

CSPCC – Certified Specialist in Pediatric Critical Care Nutrition

The CSPCC credential places special emphasis on nutrition support for infants and children. The exam assesses all aspects of the nutrition care process. Topics include anthropometric measurements specific to children, evaluation of formulas for infants, considerations for breastfeeding in the critical care setting, and assessment of nutrient needs for both normal growth and critical care recovery.

CSO – Certified Specialist in Oncology Nutrition

Dietitians with a CSO credential work with patients who have cancer or precancerous conditions and in the field of cancer prevention. The CSO exam covers special considerations for patients with cancer, such as modified diets and the impact of pharmaceutical interventions. There is also an emphasis on food safety and nutrition in end of life care. 

CSR – Certified Specialist in Renal Nutrition

The CSR credential recognizes advanced knowledge of nutrition care for patients with kidney disease. The exam covers the nutrients of concern for patients with kidney failure, evaluation of labs related to kidney disease, the comorbidities related to kidney disease, and patient education.

CSSD – Certified Specialist in Sports Dietetics 

The CSSD credential is for dietitians who work in the field of sports nutrition. Exam topics include nutrition for enhancing athletic performance, the signs and management of eating disorders, and considerations for a variety of special populations when engaging in physical activity and sports (such vegetarians and vegans, the elderly, children, and those with chronic health conditions). 

CDE – Certified Diabetes Educator (NEW: Certified Diabetes Care and Education Specialist (CDCES))

The CDCES (formerly known as the CDE) credential is administered by Certification Board for Diabetes Care and Education and includes a wide variety of health professionals. The exam covers all aspects of diabetes prevention and management. All candidates must have at least two years of experience in their discipline (i.e. two years of practice after becoming an RD) with at least 1,000 documented hours of diabetes education.

CLC/IBCLC – Certified Lactation Counselor and International Board Certified Lactation Counselor

The CLC and IBCLC credentials are for practitioners who care for mothers and infants and are not exclusive to dietitians. The two credentials are administered by different organizations: the Academy of Lactation Policy and Practice (ALPP) administers the CLC credential and the International Board of Lactation Consultant Examiners (IBLCE) administers the IBCLC credential. 

To become a CLC, you must take a 52-hour course and pass an exam. There are no practice hours required before becoming a CLC.

There are several pathways to becoming an IBCLC. If you are already a registered dietitian (or other approved health professional), you must accumulate 90 hours of lactation-specific education, 5 hours of communication training, and 1,000 hours of supervised practice related to breastfeeding counseling and management. Then you must take an exam that is offered twice a year.

The difference between a CLC and IBCLC in practice is that IBCLCs can diagnose and treat problems related to breastfeeding (such as mastitis and abscesses). Additionally, IBCLCs must go through more extensive training and therefore are more widely recognized in clinical settings. However, the accessibility of the CLC credential means that students, mothers, and community members can obtain it. 

CEDRD – Certified Eating Disorder Registered Dietitian

The CEDRD credential is administered by the International Association of Eating Disorders Professionals (IAEDP). Although this credential is for dietitians, the IAEDP also recognizes a variety of health professionals with similar certifications. To qualify to take the CEDRD exam, you must have documentation of 2,500 practice hours in eating disorder care under the supervision of an IAEDP-approved mentor.

FAND/FADA – Fellow of the Academy of Nutrition and Dietetics (formerly Fellow of the American Dietetic Association)

The FAND designation honors dietitians who have provided exemplary service to the profession. Candidates must have at least five years of experience as a registered dietitian and at least five years of Academy membership. Additionally, candidates must document service to the Academy and the professional, leadership in their work as a dietitian, and contribution to publications and/or research.