Registered Dietitian Exam Pathway 2025/2026 Version: Achieve Success Through 600 Carefully Crafted Practice Questions

By Brittany Deaton

Built for the latest Commission on Dietetic Registration (CDR) exam framework, this all-in-one guide equips aspiring Registered Dietitians with the tools, strategies, and practice needed to pass the exam with confidence.

Key Features:
Fully aligned with the 2025/2026 Registered Dietitian exam blueprint, covering all four domain areas: Principles of Dietetics, Nutrition Care for Individuals and Groups, Management of Food and Nutrition Programs and Services, and Foodservice Systems.

600 exam-style practice questions with comprehensive answer explanations to reinforce core concepts and prepare you for exam-day challenges.

Evidence-based content reflecting the most current guidelines, clinical practices, and nutrition science.

Designed to suit diverse learning styles with structured content reviews, application exercises, and test-taking strategies.

Why This Guide Stands Out:
Updated specifically for the 2025/2026 testing window—no outdated references or obsolete standards.

Focused on both knowledge retention and critical thinking for complex scenarios.

Practical, easy-to-follow layout designed to simplify complex material and reduce overwhelm.

What You’ll Gain:
Mastery of key nutrition concepts across all exam domains

Increased test-taking speed, confidence, and decision-making ability

Real-world understanding of dietetics applications in clinical, foodservice, and community settings

A solid foundation to not only pass the RD exam, but also thrive in your professional role

• Language: English
• Publisher: Tektime
• Release date: Jan 1, 2025
• ISBN: 9788835480129

Book preview

Registered Dietitian

Exam Pathway

2025/2026 Version

Achieve Success Through 600 Carefully Crafted Practice Questions

Brittany Deaton

Copyright © 2025 Brittany Deaton

This book or parts thereof may not be reproduced in any form, stored in any retrieval system, or transmitted in any form by any means—electronic, mechanical, photocopy, recording, or otherwise—without prior written permission of the publisher, except as provided by United States of America copyright law and fair use.

Disclaimer and Terms of Use

This book is an independent educational resource and is not affiliated with, authorized, endorsed, or sponsored by any official certification bodies, including but not limited to the Registered Dietitian (RD) credential or the Commission on Dietetic Registration (CDR).

All trademarks, logos, and acronyms referenced in this publication are the property of their respective owners and are used solely for identification purposes. This guide has been developed exclusively for exam preparation and educational use. The author and publisher make no representations or warranties regarding the accuracy, applicability, or completeness of the content. Use of this book does not guarantee certification or exam success.

Printed in the United States of America

TABLE OF CONTENTS

TABLE OF CONTENTS

Chapter 1 Foundations of Nutrition Science

Macronutrients & Energy Metabolism

Micronutrients: Vitamins & Minerals

Nutrition Assessment Methods

Exam Format and Structure

Chapter 2 Life Span & Clinical Nutrition

Nutrition Across the Life Cycle (Pregnancy through Older Adulthood)

Medical Nutrition Therapy for Chronic Conditions

Community & Public Health Nutrition

Chapter 3 Domain I – Nutrition Care Process & Competencies

Assessment, Diagnosis & Monitoring (100 Practice Questions)

Intervention Strategies & Evaluation (100 Practice Questions)

Chapter 4: Domain II – Professional Practice & Food Service Management

Ethics, Counseling & Education Skills (100 Practice Questions)

Food Service Systems, Safety & Quality (100 Practice Questions)

THEORY QUESTIONS

EXTRA QUESTIONS

GLOSSARY

Chapter 1 Foundations of Nutrition Science

Macronutrients & Energy Metabolism

Macronutrients and energy metabolism form the foundation of human nutrition and are crucial topics in the preparation for the Registered Dietitian Exam 2025/2026. A solid understanding of these concepts is essential, as they are closely tied to both health maintenance and clinical intervention. In simple terms, macronutrients are the nutrients the body needs in large amounts to function properly, and energy metabolism is the process by which our body converts these nutrients into usable energy. In this chapter, we will explore the types of macronutrients, their specific functions, and how they are metabolized to produce energy.

What Are Macronutrients?

Macronutrients are the nutrients that provide us with energy. There are three primary macronutrients: carbohydrates, proteins, and fats. Each of these macronutrients plays a specific role in the body and contributes differently to our total energy intake. Alcohol is sometimes included as a non-essential energy source, but for the purpose of exam preparation and health education, our focus will be on the three essential macronutrients.

Carbohydrates and proteins provide approximately 4 kilocalories (kcal) per gram, while fats provide about 9 kcal per gram. These energy values are important when calculating total energy intake, which is fundamental in diet planning and assessment.

Carbohydrates: The Body’s Primary Fuel

Carbohydrates are often referred to as the body’s preferred source of energy. They are found in foods like grains, fruits, vegetables, and dairy. Carbohydrates can be categorized as simple or complex, depending on their chemical structure and how quickly they are digested and absorbed.

Simple carbohydrates, like glucose and sucrose, are quickly broken down and absorbed into the bloodstream, leading to a rapid increase in blood sugar levels. Complex carbohydrates, such as starches and fiber, take longer to digest and provide a more sustained release of energy.

Once carbohydrates are consumed, they are broken down into glucose, the simplest form of sugar. This glucose is absorbed into the bloodstream and used by cells for energy. If the body doesn't need immediate energy, it stores glucose in the liver and muscles in the form of glycogen. When glycogen stores are full, excess glucose is converted into fat.

Carbohydrate Metabolism

The process by which carbohydrates are broken down and used for energy is known as glycolysis. During glycolysis, glucose is converted into pyruvate, yielding a small amount of energy in the form of ATP (adenosine triphosphate), which is the body's energy currency. If oxygen is available, pyruvate enters the mitochondria and is further metabolized in the Krebs cycle (also known as the citric acid cycle), followed by the electron transport chain, to produce large amounts of ATP.

In anaerobic conditions (without oxygen), such as during intense exercise, pyruvate is converted into lactate instead of entering the Krebs cycle. This process provides energy quickly but is less efficient and leads to the buildup of lactic acid, which can cause muscle fatigue.

Proteins: Building and Repairing the Body

Proteins are essential for the growth, repair, and maintenance of body tissues. They are made up of amino acids, which are often described as the building blocks of life. There are 20 amino acids, nine of which are essential, meaning the body cannot produce them and they must be obtained from the diet.

Proteins can be found in both animal (meat, dairy, eggs) and plant sources (beans, nuts, soy). Animal sources typically provide complete proteins, containing all essential amino acids, while plant sources may be incomplete and require combination with other foods to meet amino acid needs.

Though not the body's first choice for energy, protein can be used for energy when carbohydrate and fat stores are low, such as during prolonged fasting or starvation.

Protein Metabolism

When protein is consumed, it is broken down into individual amino acids through digestion. These amino acids are then used to build new proteins or repair damaged ones. If protein is used for energy, the amino group is removed in a process called deamination, and the remaining carbon skeleton can enter the Krebs cycle to produce ATP.

A byproduct of deamination is urea, which is excreted from the body via the urine. This is why adequate kidney function is important in protein metabolism, as the kidneys are responsible for removing urea from the blood.

Protein metabolism is particularly important in clinical nutrition, especially for patients recovering from surgery, trauma, or illness, when protein needs are elevated.

Fats: Energy Storage and Hormonal Support

Fats, or lipids, are the most energy-dense macronutrients, providing 9 kcal per gram. Fats are essential for many bodily functions, including the absorption of fat-soluble vitamins (A, D, E, and K), insulation, organ protection, and hormone production. Fats are found in oils, butter, nuts, seeds, and fatty meats.

There are several types of fats:

Saturated fats are typically solid at room temperature and found in animal products. Excessive intake is associated with cardiovascular risk.

Unsaturated fats, including monounsaturated and polyunsaturated fats, are generally considered heart-healthy and found in plant oils and fish.

Trans fats, often found in processed foods, are harmful and should be minimized in the diet.

Fat Metabolism

Fat metabolism begins with digestion in the small intestine, where bile acids emulsify fat into smaller droplets. Enzymes called lipases break triglycerides (the main form of dietary fat) into free fatty acids and glycerol, which are absorbed into the bloodstream.

Inside the cells, fats undergo beta-oxidation, a process that breaks down fatty acids into acetyl-CoA. Acetyl-CoA enters the Krebs cycle, just like glucose and amino acids, and continues through the electron transport chain to generate ATP.

Fat metabolism is especially important during periods of low carbohydrate availability, such as fasting or low-carbohydrate diets, where it becomes the primary energy source. Ketone bodies, a byproduct of fat metabolism, can also serve as an energy source for the brain in these situations.

Alcohol: A Non-Essential Energy Source

Although not a macronutrient in the traditional sense, alcohol provides energy—approximately 7 kcal per gram. Unlike carbohydrates, fats, and proteins, alcohol does not provide essential nutrients and can be toxic in excess. In small amounts, it may have minimal impact, but excessive consumption is associated with numerous health risks, including liver disease and nutrient deficiencies.

Alcohol is metabolized primarily in the liver through the enzyme alcohol dehydrogenase. It is prioritized for metabolism over other macronutrients because the body considers it a toxin. This prioritization can interfere with fat metabolism and contribute to fat accumulation in the liver.

Energy Balance and Metabolism

Energy metabolism refers to the process of converting the macronutrients we eat into energy that the body can use. This energy is necessary for all bodily functions, from cellular repair to physical activity.

Total Energy Expenditure (TEE) is the sum of:

Basal Metabolic Rate (BMR) – the energy required to maintain basic physiological functions at rest (e.g., breathing, circulation).

Thermic Effect of Food (TEF) – the energy required to digest, absorb, and metabolize nutrients.

Physical Activity – includes both structured exercise and general movement.

Non-Exercise Activity Thermogenesis (NEAT) – energy used in daily activities like walking or fidgeting.

Energy balance occurs when the calories consumed from macronutrients equal the calories expended through metabolism and physical activity. A positive energy balance leads to weight gain, while a negative energy balance results in weight loss. Understanding this principle is essential for dietitians in managing weight-related conditions.

Hormonal Regulation of Metabolism

Metabolism is heavily influenced by hormones that regulate how the body uses macronutrients:

Insulin promotes the uptake and storage of glucose and fat.

Glucagon stimulates the release of stored energy, especially from the liver.

Cortisol, a stress hormone, can promote protein breakdown and increase blood glucose levels.

Thyroid hormones regulate metabolic rate and influence how quickly energy is used.

These hormonal effects must be considered when planning diets, especially for patients with endocrine disorders like diabetes or thyroid disease.

Practical Applications for the RD Exam

For the Registered Dietitian Exam, understanding macronutrients and energy metabolism is not just about memorizing biochemical pathways. You will be expected to apply this knowledge in clinical and community settings. For instance:

Evaluating a patient’s energy needs.

Explaining the role of macronutrients in a nutrition counseling session.

Recognizing signs of nutrient deficiency or excess.

Applying this knowledge in Medical Nutrition Therapy (MNT) for conditions like diabetes, obesity, and cardiovascular disease.

Mastering this topic will help you answer questions across multiple domains of the exam, from nutrition assessment and planning to clinical decision-making and patient education.

Conclusion

Macronutrients—carbohydrates, proteins, and fats—are essential components of our diet, each serving distinct but overlapping functions in energy metabolism. Understanding how these nutrients are digested, absorbed, and converted into energy is key to the practice of dietetics. This knowledge enables dietitians to assess nutritional status, design appropriate interventions, and support optimal health across the lifespan. As you prepare for the Registered Dietitian Exam 2025/2026, focus on mastering both the theoretical foundations and the practical applications of macronutrients and metabolism, as they are integral to all domains of dietetic practice.

Micronutrients: Vitamins & Minerals

Micronutrients, which include vitamins and minerals, are essential nutrients that the body needs in small amounts to carry out a wide range of physiological functions. Unlike macronutrients, which provide calories and energy, micronutrients do not supply energy but are crucial for growth, immune function, brain development, and numerous biochemical reactions in the body. For the Registered Dietitian Exam 2025/2026, a clear and comprehensive understanding of micronutrients, their classifications, sources, functions, and deficiencies, is indispensable.

What Are Micronutrients?

Micronutrients are divided into two broad categories: vitamins and minerals. Both groups include essential nutrients that the body either cannot produce or produces in insufficient quantities. Therefore, they must be obtained through diet.

Vitamins are organic compounds, meaning they contain carbon, and are generally sensitive to heat, light, and air, which can degrade them during cooking or storage. Minerals, on the other hand, are inorganic elements found in soil and water and are more stable during food preparation.

We’ll begin by discussing vitamins, followed by minerals, covering their types, functions, sources, and what happens when they are deficient or consumed in excess.

Vitamins: Fat-Soluble and Water-Soluble

Vitamins are categorized based on their solubility:

Fat-soluble vitamins include vitamins A, D, E, and K. These are absorbed along with dietary fat and can be stored in the body’s fat tissues and liver.

Water-soluble vitamins include the B-complex vitamins and vitamin C. These are not stored in large amounts and must be consumed regularly.

Fat-Soluble Vitamins

Vitamin A is essential for vision, immune function, and skin health. It exists in two main forms: preformed vitamin A (retinol) found in animal products, and provitamin A (beta-carotene) found in colorful fruits and vegetables. Deficiency can lead to night blindness and increased susceptibility to infections, while excess intake (especially from supplements) can be toxic.

Vitamin D plays a major role in calcium absorption and bone health. It is synthesized in the skin upon exposure to sunlight and is also found in fortified foods and fatty fish. Deficiency leads to rickets in children and osteomalacia in adults. Excessive intake can cause calcium buildup in the blood, leading to kidney problems.

Vitamin E acts as an antioxidant, protecting cells from damage. It is found in nuts, seeds, and vegetable oils. Deficiency is rare but can lead to nerve and muscle damage. Excess supplementation can interfere with blood clotting.

Vitamin K is crucial for blood clotting and bone metabolism. Leafy greens like spinach and kale are rich sources. Deficiency can result in bleeding disorders, particularly in newborns or individuals on blood thinners. Excess is rare but can interfere with anticoagulant medications.

Water-Soluble Vitamins

Vitamin C, also known as ascorbic acid, is important for collagen synthesis, wound healing, and immune support. It is abundant in citrus fruits, berries, and peppers. Deficiency leads to scurvy, characterized by bleeding gums and poor wound healing. As it is water-soluble, excess amounts are excreted in urine, though very high doses may cause stomach upset.

B-complex Vitamins include several distinct vitamins with individual functions:

B1 (Thiamine) supports energy metabolism and nerve function. Deficiency causes beriberi or Wernicke-Korsakoff syndrome.

B2 (Riboflavin) is vital for energy production and cell function. Deficiency can lead to cracked lips and a swollen tongue.

B3 (Niacin) is essential for metabolic processes and DNA repair. Pellagra, marked by dermatitis, diarrhea, and dementia, results from deficiency.

B5 (Pantothenic Acid) aids in the synthesis of coenzyme A, critical for metabolism.

B6 (Pyridoxine) is involved in amino acid metabolism and neurotransmitter synthesis. Deficiency may cause anemia and depression.

B7 (Biotin) supports hair, skin, and nail health, and is important in metabolic processes.

B9 (Folate) is key for DNA synthesis and cell division. Deficiency, especially during pregnancy, can result in neural tube defects.

B12 (Cobalamin) is necessary for red blood cell formation and neurological function. Found only in animal products, its deficiency can cause pernicious anemia and nerve damage.

Since B vitamins and vitamin C are not stored in large quantities, consistent dietary intake is vital.

Minerals: Major and Trace

Minerals are categorized into major (macro) and trace (micro) minerals based on the amount the body requires. Major minerals are needed in larger amounts, while trace minerals are needed in very small quantities but are equally essential.

Major Minerals

Calcium is the most abundant mineral in the body and is essential for bone structure, muscle function, and nerve signaling. Found in dairy, leafy greens, and fortified products, calcium deficiency can lead to osteoporosis. Excessive intake can cause kidney stones.

Phosphorus works with calcium to build bones and teeth and is involved in energy production. It is found in meat, dairy, and processed foods. Deficiency is rare, but excess can affect kidney function.

Magnesium is involved in over 300 biochemical reactions, including muscle and nerve function, and maintaining heart rhythm. Sources include nuts, whole grains, and leafy greens. Deficiency can lead to muscle cramps and abnormal heart rhythms.

Sodium, essential for fluid balance and nerve function, is found in table salt and processed foods. While necessary, excessive intake is linked to hypertension.

Potassium helps regulate fluid balance and muscle contractions. It is abundant in bananas, potatoes, and beans. Deficiency can cause weakness and irregular heartbeat.

Chloride, often paired with sodium, helps maintain fluid balance and is part of stomach acid (hydrochloric acid). Found in salt and vegetables.

Sulfur is a component of