RDN Dietary Assessment 3 — Questions and Answers
Question 1: Which biomarker is used to validate protein intake reported on dietary assessment tools?
- Serum albumin
- 24-hour urinary nitrogen (Correct answer)
- Serum prealbumin
- C-reactive protein
Correct answer: 24-hour urinary nitrogen
24-hour urinary nitrogen output is a reliable biomarker for verifying dietary protein intake because urinary urea nitrogen reflects protein catabolism.
Question 2: A food frequency questionnaire (FFQ) is BEST suited for which of the following research purposes?
- Precise individual nutrient quantification
- Ranking individuals by dietary exposure in epidemiological studies (Correct answer)
- Monitoring daily intake changes
- Clinical nutrition therapy planning
Correct answer: Ranking individuals by dietary exposure in epidemiological studies
FFQs are designed to rank individuals by long-term dietary patterns and are widely used in large-scale epidemiological research.
Question 3: Attenuation bias in nutrition research refers to which phenomenon?
- Overestimation of dietary effects due to large sample sizes
- Underestimation of diet-disease associations due to measurement error (Correct answer)
- Confounding introduced by supplement use
- Bias from excluding non-responders
Correct answer: Underestimation of diet-disease associations due to measurement error
Measurement error in dietary assessment attenuates (weakens) observed associations between diet and disease outcomes toward the null.
Question 4: When assessing dietary intake in an elderly patient with cognitive decline, which method is MOST appropriate?
- Self-administered food frequency questionnaire
- Proxy-assisted 24-hour dietary recall (Correct answer)
- Unassisted weighed food record
- Online diet tracking app
Correct answer: Proxy-assisted 24-hour dietary recall
Proxy-assisted recalls involve a caregiver or family member providing dietary information, which improves accuracy when the patient cannot self-report reliably.
Question 5: The 'flat slope syndrome' in dietary assessment describes a situation where:
- All respondents report similar intakes regardless of true variation
- High consumers under-report and low consumers over-report (Correct answer)
- Energy intake remains constant across different activity levels
- Portion sizes are systematically overestimated
Correct answer: High consumers under-report and low consumers over-report
Flat slope syndrome describes regression to the mean in dietary reporting, where high consumers under-report and low consumers over-report, compressing the true distribution.
Question 6: Which of the following is a key advantage of the diet history method compared to a 24-hour recall?
- Requires less interviewer training
- Captures usual dietary patterns over a longer time period (Correct answer)
- Is less subject to recall bias
- Takes less time to administer
Correct answer: Captures usual dietary patterns over a longer time period
The diet history interview captures habitual dietary patterns over weeks or months, providing a broader picture of usual intake than a single-day recall.
Question 7: A registered dietitian is comparing nutrient intake data to Dietary Reference Intakes (DRIs). Which DRI value is used to assess the adequacy of an individual's diet?
- Estimated Average Requirement (EAR)
- Recommended Dietary Allowance (RDA) (Correct answer)
- Tolerable Upper Intake Level (UL)
- Adequate Intake (AI)
Correct answer: Recommended Dietary Allowance (RDA)
The RDA meets the needs of 97-98% of healthy individuals and is used as the target for individual intake assessment.
RDN Dietary Assessment 3
Which biomarker is used to validate protein intake reported on dietary assessment tools?