RDN Clinical Nutrition 2 — Questions and Answers
Question 1: A patient with chronic kidney disease (CKD) stage 4 requires dietary phosphorus restriction. Which food group poses the greatest phosphorus burden due to phosphate additives?
- Fresh fruits
- Processed meats and fast foods (Correct answer)
- Whole grains
- Raw vegetables
Correct answer: Processed meats and fast foods
Processed meats and fast foods contain inorganic phosphate additives that are nearly 100% bioavailable, far exceeding the phosphorus burden of natural food sources.
Question 2: Which indirect calorimetry measurement indicates a patient is in a hypermetabolic state?
- Respiratory quotient (RQ) of 0.85
- Measured REE equal to predicted REE
- Measured REE 125% of predicted REE (Correct answer)
- RQ of 0.70
Correct answer: Measured REE 125% of predicted REE
A measured REE that is ≥120–130% of predicted REE indicates hypermetabolism, commonly seen in burn, sepsis, or trauma patients.
Question 3: A post-bariatric surgery patient (Roux-en-Y gastric bypass) presents with paresthesias and ataxia 18 months post-op. Which nutrient deficiency is most likely?
- Vitamin A
- Copper (Correct answer)
- Thiamine
- Vitamin K
Correct answer: Copper
Copper deficiency after RYGB presents with neurological symptoms including peripheral neuropathy and myelopathy, often misdiagnosed as B12 deficiency.
Question 4: In the ESPEN guidelines, what is the recommended protein intake for critically ill patients receiving nutrition support?
- 0.5–0.8 g/kg/day
- 0.8–1.0 g/kg/day
- 1.3–2.0 g/kg/day (Correct answer)
- 2.5–3.5 g/kg/day
Correct answer: 1.3–2.0 g/kg/day
ESPEN recommends 1.3–2.0 g protein/kg/day for critically ill patients to attenuate muscle catabolism and support immune function.
Question 5: Which lab value most accurately reflects chronic protein-energy malnutrition over a 3-month period?
- Serum albumin (Correct answer)
- Prealbumin (transthyretin)
- Hemoglobin A1c pattern
- C-reactive protein
Correct answer: Serum albumin
Although not highly sensitive to acute changes, serum albumin's 20-day half-life and volume of distribution make it a marker of chronic nutritional and inflammatory status.
Question 6: A patient with short bowel syndrome has a jejunostomy with only 80 cm of remaining small bowel. Which macronutrient adaptation is most important to maximize absorption?
- High-fat diet to increase caloric density
- Low-fat diet with high complex carbohydrates
- High-protein, low-carbohydrate diet
- Continuous enteral feeding with elemental formula (Correct answer)
Correct answer: Continuous enteral feeding with elemental formula
Continuous elemental feeding maximizes absorption surface contact time and reduces osmotic load in patients with minimal intestinal length.
Question 7: Which condition is associated with refeeding syndrome and dangerous hypophosphatemia?
- Overfeeding a well-nourished ICU patient
- Rapid introduction of calories to a severely malnourished patient (Correct answer)
- Providing high-protein feeds to a CKD patient
- Starting TPN in a patient with hyperphosphatemia
Correct answer: Rapid introduction of calories to a severely malnourished patient
Rapid caloric reintroduction in severe malnutrition drives phosphate into cells with insulin release, precipitating life-threatening hypophosphatemia (refeeding syndrome).
RDN Clinical Nutrition 2
A patient with chronic kidney disease (CKD) stage 4 requires dietary phosphorus restriction.
Which food group poses the greatest phosphorus burden due to phosphate additives?