The Registered Dietitian Nutritionist (RDN) credential is awarded by the Commission on Dietetic Registration (CDR), the credentialing arm of the Academy of Nutrition and Dietetics. Passing the CDR examination is required to use the RDN title and practice as a registered dietitian in the United States. The exam is computer-adaptive, drawing from a large question bank, and covers four major practice domains: Principles of Dietetics, Nutrition Care for Individuals and Groups, Management of Food and Nutrition Programs and Services, and Food Service Systems. Practice with the free Registered Dietitian Nutritionist practice test on PracticeTestGeeks (7 questions with answer explanations).
Our free downloadable PDF gives you a printable set of practice questions spanning all four CDR exam domains. Study at the library, annotate the pages, share with a study group, or work through the questions on your commute — wherever printed materials fit your schedule. The answer key with rationales is included so you can understand the reasoning behind every correct answer, not just memorize responses.
Facts verified Oct 26, 2026 against Commission on Dietetic Registration (CDR), the credentialing agency of the Academy of Nutrition and Dietetics. Dates that have passed are removed automatically.
Facts verified Oct 26, 2026 against Commission on Dietetic Registration (CDR), the credentialing agency of the Academy of Nutrition and Dietetics. Dates that have passed are removed automatically.
Facts verified Oct 26, 2026 against Commission on Dietetic Registration (CDR), the credentialing agency of the Academy of Nutrition and Dietetics. Dates that have passed are removed automatically.
Interactive Registered Dietitian Nutritionist resources on PracticeTestGeeks, free to start:
The first CDR domain covers the scientific foundations of dietetic practice. Candidates must demonstrate knowledge of macronutrient structure and function — carbohydrates (simple vs. complex, glycemic index, fiber classifications), proteins (essential amino acids, nitrogen balance, protein quality measures such as PDCAAS and DIAAS), and lipids (saturated, unsaturated, and trans fatty acids; omega-3 and omega-6 roles; phospholipids and cholesterol metabolism). Micronutrient content — fat-soluble vitamins (A, D, E, K), water-soluble vitamins (B-complex, C), and minerals (calcium, iron, zinc, iodine) — is also tested, including deficiency and toxicity presentations. The Dietary Reference Intakes framework (EAR, RDA, AI, UL, AMDR) underpins much of this domain.
Diabetes management is among the most heavily tested MNT topics on the RDN exam. Candidates must understand the diagnostic criteria for Type 1, Type 2, and gestational diabetes, as well as prediabetes and metabolic syndrome. Nutrition interventions include carbohydrate counting methods, the plate method, glycemic index guidance, and meal-timing strategies for patients using insulin. The RDN exam also tests knowledge of hypoglycemia management (the 15-15 rule), the impact of physical activity on blood glucose, and how to adjust nutrition recommendations based on HbA1c targets. Candidates should understand how to calculate carbohydrate-to-insulin ratios and correction factors for patients on flexible insulin regimens.
Chronic kidney disease (CKD) and end-stage renal disease (ESRD) require careful nutrient restriction and monitoring. The RDN exam tests knowledge of protein restriction in CKD stages 3–5 (typically 0.6–0.8 g/kg/day for non-dialysis patients), potassium and phosphorus limitations, fluid restriction in dialysis patients, and sodium reduction guidelines. For hemodialysis patients, protein requirements increase to 1.2–1.4 g/kg/day to account for dialytic losses. Candidates must also understand how to interpret relevant labs — serum creatinine, BUN, GFR, phosphorus, potassium, albumin — and how nutrition interventions affect these values over time.
Cardiovascular nutrition therapy on the RDN exam covers atherosclerosis risk reduction, heart failure, and post-cardiac event rehabilitation. Key topics include dietary fat quality (replacing saturated and trans fats with unsaturated fats), sodium restriction targets for hypertension and heart failure (typically 1,500–2,000 mg/day), the DASH dietary pattern, plant sterol and stanols as adjunct therapy, and omega-3 fatty acid evidence for triglyceride reduction. The exam also tests understanding of cardiac cachexia in advanced heart failure — a state of involuntary weight loss requiring aggressive nutrition support — and how to differentiate it from simple caloric restriction.
Nutrition support is a high-yield topic. Enteral nutrition (tube feeding) questions cover indications (functional GI tract but inability to meet oral intake), formula selection (standard polymeric, semi-elemental, disease-specific), delivery routes (nasogastric, nasoenteric, PEG, jejunostomy), and monitoring for complications including aspiration, diarrhea, and refeeding syndrome. Parenteral nutrition (PN) questions cover indications (non-functional GI tract), peripheral vs. central PN, macronutrient composition (dextrose, amino acids, lipid emulsions), electrolyte requirements, and monitoring labs (triglycerides, glucose, liver function tests, electrolytes). The refeeding syndrome triad — hypophosphatemia, hypokalemia, and hypomagnesemia — is a classic exam question topic.
The management domains test organizational and operational knowledge alongside nutrition science. Food service systems questions cover conventional, commissary, ready-prepared, and assembly-serve production systems, procurement methods (formal competitive bidding, informal purchasing), inventory control (par stock, just-in-time), and production planning. Food safety questions are built around HACCP (Hazard Analysis and Critical Control Points) — candidates must know how to identify biological, chemical, and physical hazards, set critical control points, establish critical limits (e.g., internal cooking temperatures), and determine corrective actions when limits are not met. Temperature danger zone (41°F–135°F), proper cooling procedures (135°F to 70°F within 2 hours, 70°F to 41°F within 4 hours), and hand-washing standards are also tested.
The Academy of Nutrition and Dietetics Nutrition Care Process provides the framework for clinical documentation. ADIME stands for Assessment, Diagnosis, Intervention, and Monitoring/Evaluation. Assessment gathers anthropometric, biochemical, clinical, dietary, and environmental data. Nutrition Diagnosis uses standardized language from the International Dietetics and Nutrition Terminology (IDNT) reference, with diagnoses written in PES (Problem, Etiology, Signs/Symptoms) statement format. Intervention documents the nutrition prescription and counseling plan. Monitoring and Evaluation tracks progress against established goals and adjusts the plan as needed. The RDN exam tests both the process framework itself and the ability to apply it correctly to a clinical case scenario.
Prefer interactive study? Our browser-based registered dietitian practice test gives you timed exam simulations with instant scoring and full answer explanations across all CDR exam domains.
| Pros | Cons |
|---|---|
| Validates your knowledge and skills objectively | Study materials can be expensive |
| Increases job market competitiveness | Exam anxiety can affect performance |
| Provides structured learning goals | Requires dedicated preparation time |
| Networking opportunities with other certified professionals | Retake fees apply if you don't pass |
Try these questions from our free Registered Dietitian Nutritionist practice tests. The correct answer and an explanation follow each question.
What distinguishes quality assurance from quality control in Registered Dietitian Nutritionist practice?
Answer: B. QA focuses on preventing defects through process improvement while QC detects defects through inspection
This is fundamental to Registered Dietitian Nutritionist practice. QA focuses on preventing defects through process improvement while QC detects defects through inspection represents the professional standard for quality in the Registered Dietitian Nutritionist certification framework.
What is the purpose of a quality audit in Registered Dietitian Nutritionist practice?
Answer: B. To systematically evaluate processes against standards and identify improvement opportunities
This is fundamental to Registered Dietitian Nutritionist practice. To systematically evaluate processes against standards and identify improvement opportunities represents the professional standard for quality in the Registered Dietitian Nutritionist certification framework.
What is a risk mitigation strategy in Registered Dietitian Nutritionist practice?
Answer: B. Implementing controls that reduce the likelihood or impact of identified risks
This is fundamental to Registered Dietitian Nutritionist practice. Implementing controls that reduce the likelihood or impact of identified risks represents the professional standard for risk management in the Registered Dietitian Nutritionist certification framework.
What role does peer review play in Registered Dietitian Nutritionist practice?
Answer: B. It provides quality assurance and professional development through collegial evaluation
This is fundamental to Registered Dietitian Nutritionist practice. It provides quality assurance and professional development through collegial evaluation represents the professional standard for professional standards in the Registered Dietitian Nutritionist certification framework.
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