Basic Nutrition

Nutrition as a Clinical Foundation for CNAs

Basic nutrition is a foundational concept for the Certified Nursing Assistant (CNA). As a CNA, you are often the first to observe changes in a patient's appetite, ability to eat, or tolerance to food. Proper nutrition supports wound healing, maintains muscle mass, and prevents complications such as pressure injuries and infections.^[1] On the CNA exam, you will be tested on identifying nutrient groups, assisting with meals, recognizing signs of malnutrition, and understanding special diets.

Six Essential Nutrients and MyPlate Guidelines

Six Essential Nutrients

• Carbohydrates – primary energy source (breads, grains, fruits).
• Proteins – tissue repair and immune function (meat, eggs, beans).
• Fats – energy storage and vitamin absorption (oils, butter, nuts).
• Vitamins – regulate body processes (from vegetables, fruits).
• Minerals – bone health, fluid balance (calcium, iron, potassium).
• Water – most essential nutrient; aids digestion and temperature regulation.^[2]

Calories and MyPlate

Calorie: unit of energy provided by food. The USDA MyPlate guide divides a plate into five food groups: fruits, vegetables, grains, protein, and dairy. A balanced meal includes half fruits/vegetables, one-quarter grains, and one-quarter protein.^[3]

Feeding Assistance Protocols and Diet Specifications

Assisted Feeding Process (step-by-step)

1. Wash hands and set up the patient in a sitting position (45–90 degrees).
2. Identify the patient using two identifiers and check for dietary orders.
3. Offer small bite-sized portions; allow the patient to set the pace.
4. Alternate between food and drink to prevent dry mouth.
5. Observe for signs of dysphagia (coughing, pocketing food, wet voice).
6. Provide oral care after meals to maintain oral hygiene.^[4]

Special Diets

Always verify the diet order before serving. For NPO (nothing by mouth) patients, do not offer any food or drink – a common high-yield exam point.^[5]

Clinical Signs of Malnutrition in Patients

• Unintentional weight loss (especially >5% in one month).
• Poor wound healing or frequent infections.
• Muscle wasting (temporal hollowing, decreased grip strength).
• Dry, brittle nails and thin hair.
• Edema (due to low protein).^[6]

Report these signs to the supervising nurse promptly.

Nutrition Monitoring and Documentation Duties

CNAs assist with nutrition-related assessments by:

• Recording meal percentages eaten (e.g., 50%, 75%).
• Weighing patients weekly (using consistent scales).
• Documenting fluid intake (I&O records) for hydration monitoring.
• Noting food allergies or refusals.^[7]

On the exam, you must know that the CNA does not make dietary diagnoses – those are the responsibility of the RN or dietitian.

Strategies to Promote Oral Intake and Hydration

Promoting Oral Intake

• Provide pleasant environment: remove bedpans, reduce odors, offer companionship.
• Assist with hand hygiene and positioning before meals.
• Allow adequate time; do not rush the patient.
• Respect cultural and religious food preferences whenever possible.^[8]

Hydration Strategies

• Offer fluids between meals, especially for patients with low thirst.
• Recognize signs of dehydration: dry mouth, dark urine, confusion, decreased skin turgor.
• For thickened liquids (honey, nectar, pudding consistency), follow the speech-language pathologist’s orders exactly – do not alter the thickness.^[9]

Feeding-Related Safety Risks and Preventive Measures

• Choking: cut food into small pieces; supervise high-risk patients.
• Aspiration: keep head of bed elevated at least 30° during meals and for 30 minutes afterward.
• Tube feeding (gastrostomy or nasogastric): never administer tube feeding unless trained and directed by a nurse.
• Food allergies: check the allergy list each time you serve a tray.
• Refeeding syndrome: a potentially fatal condition if malnourished patients are given large amounts of carbohydrates too quickly – report any sudden changes after feeding.^[10]

Critical Test Points on Nutrition and Hydration

• Know the order of special diets: clear liquid → full liquid → mechanical soft → regular.
• NPO = nothing by mouth, including water, ice chips, and even toothbrushing with water (only if ordered).
• Feeding assistance: always sit the patient upright, use adaptive utensils if needed, and never force food.
• Thickened liquids are prescribed for dysphagia; never thin them down.
• Weighing patients: same time of day, same scale, minimal clothing, and calibrate scale.
• Memory aid for signs of malnutrition: “Weight, Wounds, Weakness, and Wasting” (the 4 Ws).

References

1. Potter PA, Perry AG, Stockert PA, Hall AM. Fundamentals of Nursing. 10th ed. Elsevier; 2021: 1050-1055. https://shop.elsevier.com/books/fundamentals-of-nursing/potter/978-0-443-12406-8
2. National Institutes of Health (NIH). Nutrient Recommendations: Dietary Reference Intakes (DRIs). Updated 2023. https://ods.od.nih.gov/HealthInformation/nutrientrecommendations.aspx
3. U.S. Department of Agriculture (USDA). MyPlate. https://www.myplate.gov/
4. National Council of State Boards of Nursing (NCSBN). CNA Exam Blueprint. 2022. https://www.ncsbn.org/exams/exam-statistics-and-publications/exam-publications.page
5. Sorrentino SA, Remmert L. Mosby's Textbook for Nursing Assistants. 10th ed. Elsevier; 2020: 285-295. https://shop.elsevier.com/books/mosbys-textbook-for-nursing-assistants-soft-cover-version/sorrentino/978-0-323-65560-6
6. White JV, Guenter P, Jensen G, et al. Consensus statement: Academy of Nutrition and Dietetics and American Society for Parenteral and Enteral Nutrition: characteristics recommended for the identification and documentation of adult malnutrition (undernutrition). JPEN J Parenter Enteral Nutr. 2012;36(3):275-283. https://doi.org/10.1177/0148607112440285
7. Centers for Medicare & Medicaid Services (CMS). State Operations Manual Appendix PP – Guidance to Surveyors for Long Term Care Facilities (F323 Tag: Nutrition). https://www.cms.gov/Regulations-and-Guidance/Guidance/Manuals/Downloads/som107ap_pp_guidelines_ltcf.pdf
8. American Association of Colleges of Nursing (AACN). Cultural Competency in Nursing Education. https://www.aacnnursing.org/Education-Resources/Tool-Kits/Cultural-Competency-in-Nursing-Education
9. Logemann JA. Evaluation and Treatment of Swallowing Disorders. 2nd ed. PRO-ED; 2020: 145-150. https://www.amazon.com/Evaluation-Treatment-Swallowing-Disorders-Logemann/dp/0890797285
10. Mehanna HM, Moledina J, Travis J. Refeeding syndrome: what it is, and how to prevent and treat it. BMJ. 2008;336(7659):1495-1498. https://doi.org/10.1136/bmj.a301