RD exam practice test: 30 questions with rationales

A cook's mayonnaise made with only egg whites separates, while the batch made with egg yolks stays smooth. Which egg component explains the difference?

Choose a letter. The key opens with a short note under each of the choices.

1. AAvidinCheck

   Avidin is an egg-white protein known for binding biotin; the white-only batch had plenty of it and still separated.
2. BLuteinCheck

   Lutein is a yolk pigment that adds color and has no emulsifying action.
3. COvalbuminCheck

   Ovalbumin is the main egg-white protein, so the batch that broke already contained it.
4. DLecithinCheck

   Lecithin, a yolk phospholipid, has a water-loving end and a fat-loving end, so it coats oil droplets and keeps the emulsion stable.

A clinical dietitian wants to change a local feeding protocol based on a published retrospective study of electronic health records from another health system. What should the dietitian evaluate first?

1. AWhether the study was registered as a clinical trialCheck

   Trial registration applies to prospective interventional studies, and a retrospective record review is not a clinical trial.
2. BWhether local patients will sign consent formsCheck

   Changing practice on published evidence is not research on local patients, so research consent forms do not apply.
3. CWhether the study used double-blindingCheck

   Blinding belongs to prospective trials; a review of existing health records has no treatment assignment to blind.
4. DWhether the study population resembles local patientsCheck

   Records from another health system may describe different patients and care, so whether the findings apply to the local population comes first.

A cook's fudge turns out coarse and grainy. Which practice most likely caused it?

1. ALetting it cool undisturbed to 110°F before beatingCheck

   Cooling undisturbed to about 110°F and then beating is the correct method, and it produces many tiny crystals and a smooth fudge.
2. BStirring the syrup while it was still very hotCheck

   Stirring hot, supersaturated syrup starts crystallization too early, which yields a few large crystals and a grainy fudge.
3. CAdding corn syrup to the sugar mixtureCheck

   Corn syrup is an interfering agent that limits crystal growth, so it makes fudge smoother, not grainier.
4. DWashing sugar crystals from the sides of the panCheck

   Washing down the pan sides removes stray crystals that would seed early crystallization, so it prevents graininess.

A high-protein bar made with milk protein and fructose darkens and loses protein quality during months of storage. Which change in the protein best explains the loss of quality?

1. ATryptophan is converted to niacinCheck

   Tryptophan becomes niacin only through metabolism in the body, not during storage of a packaged bar.
2. BCasein is hydrolyzed by the fructoseCheck

   Sugars do not hydrolyze proteins, so fructose does not break casein apart; it binds lysine instead.
3. CLysine is bound in Maillard reactionsCheck

   Lysine's free amino group reacts with reducing sugars such as fructose, and lysine tied up in Maillard products can no longer be used by the body.
4. DLeucine is oxidized by light exposureCheck

   Light mainly damages fats and riboflavin, and leucine loss would not explain the browning that came with the quality drop.

Researchers estimate sodium intake of recent immigrants using a food database that lacks many of their traditional foods, so coders substitute similar mainstream foods. This problem is best described as:

1. Asystematic error that reduces validityCheck

   Substituting mainstream foods shifts the group estimates in one direction, a systematic error that lowers validity.
2. Blow reliability caused by inconsistent codersCheck

   Reliability is about consistency; coders who applied the same substitution every time would be reliable and still wrong.
3. Cconfounding by socioeconomic statusCheck

   Confounding needs a third factor linked to both exposure and outcome, while this is a measurement problem in the database.
4. Drandom error that a larger sample would correctCheck

   Random error scatters both ways and shrinks with more participants, but a biased database stays biased at any sample size.

A patient receiving head and neck radiation has the diagnosis 'Inadequate oral intake related to mucositis pain.' The RDN cannot resolve the mucositis. What should the nutrition intervention target?

1. ARelabeling it as malnutritionCheck

   Relabeling the diagnosis does not change what the RDN can act on; the problem as written still needs an intervention.
2. BTreating the mucositis itselfCheck

   Treating mucositis is a medical task, which is exactly why the etiology lies outside the nutrition intervention here.
3. CEasing its signs and symptomsCheck

   When the RDN cannot change the etiology, the intervention aims at the signs and symptoms, for example with soft, moist, energy-dense foods.
4. DDeferring care until the mucosa healsCheck

   Waiting for the mucosa to heal lets intake and weight keep falling for the rest of radiation.

Based on WHO velocity standards, a 7-month-old infant is expected to gain about 12 g/day but has gained 5 g/day over the past month. Using AND/ASPEN pediatric criteria for weight-gain velocity in children under 2 years, how is this graded?

1. AModerate malnutritionCheck

   A gain of 5 g/day against an expected 12 g/day is about 42% of the norm, and AND/ASPEN grades velocity below 50% as moderate.
2. BMild malnutritionCheck

   Mild applies to a velocity below 75% but at least 50% of expected; reading the 58% shortfall as the amount gained leads here.
3. CNo malnutrition; gain is positiveCheck

   Under age 2, a gain well below the expected rate is itself a malnutrition indicator, even while weight is still rising.
4. DSevere malnutritionCheck

   Severe requires a velocity below 25% of expected, and this infant still gains about 42% of the norm.

A patient newly diagnosed with celiac disease asks which grain she can use in place of wheat pasta. Which choice is appropriate?

1. ABarleyCheck

   Barley contains hordein, a gluten protein, and has to be avoided in celiac disease.
2. BQuinoaCheck

   Quinoa is a naturally gluten-free seed that can replace wheat pasta, ideally as a product labeled gluten-free to avoid cross-contact.
3. CRyeCheck

   Rye contains secalin, a gluten protein that triggers the same immune response as wheat.
4. DSpeltCheck

   Spelt is a species of wheat that is often sold as an ancient grain, and it contains gluten.

A nursing home resident with dysphagia was changed to IDDSI Level 3 (moderately thick) drinks 2 weeks ago. Which parameter is most important to monitor closely?

1. ASerum albumin and prealbuminCheck

   Albumin and prealbumin shift with inflammation and hydration and do not track how much the resident drinks.
2. BFluid intake and signs of dehydrationCheck

   Thickened drinks are less appealing and quench thirst poorly, so residents often drink less, and intake and dehydration signs need close watching.
3. CWeekly dietary fiber intakeCheck

   A change in drink consistency does not drive fiber intake, so fiber is not the main risk to watch.
4. DBlood glucose from the starch thickenerCheck

   Starch thickeners add only a small amount of carbohydrate per serving, so blood glucose is not the main concern.

In an outpatient clinic where malnutrition prevalence is 5%, a screening tool with 90% sensitivity and 85% specificity is negative for a patient. What is the approximate probability that the patient is truly well nourished?

1. A85%Check

   85% is the specificity, the share of well-nourished patients who screen negative, not the chance that a negative result is correct.
2. B95%Check

   95% is the share of patients who are well nourished before any testing, so it ignores the screen result.
3. C90%Check

   90% is the sensitivity, which describes how many malnourished patients the tool catches.
4. D99%Check

   Per 1,000 patients, 808 of the 950 well nourished screen negative and only 5 of the 50 malnourished do, so a negative result is right 808 ÷ 813, or about 99%, of the time.

An older adult stopped drinking her prescribed oral supplement after 2 weeks, saying she is tired of the taste. What should the dietitian recommend?

1. AStop the supplement and recheck weight monthlyCheck

   Stopping support in an older adult who needed it invites weight loss well before the next monthly weight check.
2. BRotate flavors and add fortified foodsCheck

   Taste fatigue is the barrier, and rotating flavors while adding fortified foods keeps energy and protein intake up without relying on one product.
3. CChange to a 2.0 kcal/mL supplementCheck

   A more concentrated supplement reduces the volume but does nothing about the taste she is tired of.
4. DAsk the provider for an appetite stimulantCheck

   An appetite stimulant adds side effects and does not fix dislike of the product; the problem is taste, not appetite.

A patient's small-bore feeding tube has clogged twice this week. Staff crush several medications and give them together through the tube. Which practice most reduces future clogs?

1. AFlush only when the feeding is stoppedCheck

   Flushing only at stops leaves drug and formula residue sitting in a small-bore tube, which is how clogs form.
2. BFlush the tube with cola after each medicationCheck

   Acidic drinks such as cola can make formula protein clump and clear tubes no better than warm water.
3. CMix the medications into the formula bagCheck

   Medications mixed into formula can interact with it, curdle it, and change the dose the patient actually receives.
4. DGive each drug separately with water flushesCheck

   Giving each drug on its own, in liquid form when possible, with water flushes before, between, and after doses keeps residue from clumping in the tube.

A 5-year-old with IgE-mediated egg allergy has had no reactions for 2 years, and her egg-specific IgE has fallen. How should the team determine whether she has outgrown the allergy?

1. AA trial of scrambled egg at homeCheck

   A home trial of egg risks anaphylaxis without medical help on hand.
2. BFood-specific IgG testingCheck

   Food-specific IgG reflects exposure to a food, not allergy, and is not recommended for diagnosing or clearing allergies.
3. CA supervised oral food challengeCheck

   A physician-supervised oral food challenge is the standard way to confirm tolerance, because falling IgE suggests but does not prove that the allergy is gone.
4. DA repeat skin prick test aloneCheck

   A smaller skin prick wheal, like a falling IgE, only predicts tolerance and cannot confirm it on its own.

A patient on hemodialysis has interdialytic weight gains of 4.5 kg (about 5% of dry weight). What should the dietitian assess first?

1. APotassium intake from fruitCheck

   Potassium from fruit matters for serum potassium, but it does not explain 4.5 kg of fluid gained between treatments.
2. BPhosphate binder adherenceCheck

   Binder adherence affects serum phosphorus, not the fluid weight gained between sessions.
3. CSodium and fluid intakeCheck

   Gains between treatments are fluid, and high sodium intake drives thirst, so sodium and fluid intake are the first things to review.
4. DProtein intake at mealsCheck

   Protein intake shapes albumin and nutrition status; it is not what drives a large fluid gain.

A patient with a BMI of 36 was admitted with acute pancreatitis 2 weeks ago. She has eaten less than 50% of needs for 10 days, lost 6% of body weight in 1 month, and has moderate temporal wasting on NFPE. What should the RDN conclude?

1. ASevere malnutritionCheck

   In acute illness, intake of 50% or less for at least 5 days, more than 5% weight loss in a month, and moderate muscle loss each meet the AND/ASPEN severe level.
2. BNo malnutrition; BMI over 30Check

   A high BMI can hide muscle loss but does not rule out malnutrition, which is judged from intake, weight change, and physical findings.
3. CObesity; the loss is desirableCheck

   Unintended loss during acute illness comes largely from muscle and is harmful whatever the starting BMI.
4. DNon-severe malnutritionCheck

   Non-severe fits smaller losses or intake below 75% for more than 7 days, and this patient exceeds those thresholds.

The hospital's infection-control nurse advises the foodservice department on sanitation practices but cannot direct foodservice employees. This relationship is best described as:

1. AFunctional authorityCheck

   Functional authority would let the nurse direct foodservice employees on specific sanitation procedures, which the stem rules out.
2. BLine authorityCheck

   Line authority runs from supervisor to employee within a department, and the nurse holds none over foodservice staff.
3. CStaff authorityCheck

   Staff authority is advisory: specialists such as the infection-control nurse recommend practices but cannot give orders outside their own department.
4. DChain of commandCheck

   The chain of command is the reporting line itself, not an advisory relationship between departments.

A clinical nutrition department writes several objectives. Which is an operational (short-range) objective?

1. ABecome the region's most trusted provider of nutrition careCheck

   Becoming the region's most trusted provider is a vision statement, broad and without a measure or deadline.
2. BScreen 95% of patients within 24 hours of admission each dayCheck

   An operational objective covers day-to-day work over a short period, like screening patients within 24 hours of admission every day.
3. CReduce inpatient malnutrition prevalence by 25% over 3 yearsCheck

   A 3-year reduction target is a long-range, strategic objective set by top management.
4. DLaunch a malnutrition quality program within the next 2 yearsCheck

   Launching a program over the next 2 years is an intermediate-range, tactical objective, not daily operations.

An RDN's private practice advertises on three online channels with very different budgets. Which metric best shows which channel produces bookings at the lowest cost?

1. ABookings divided by clicksCheck

   Bookings divided by clicks is the conversion rate; it shows how well clicks turn into bookings but ignores what each channel costs.
2. BSpend divided by bookingsCheck

   Spend divided by bookings is the cost per booking, which ties each channel's money to the result that matters.
3. CSpend divided by clicksCheck

   Spend divided by clicks is the cost per click, an earlier funnel step that says nothing about whether clicks become bookings.
4. DClicks divided by impressionsCheck

   Clicks divided by impressions is the click-through rate, a measure of ad appeal rather than of cost or bookings.

A long-term care resident refuses the chicken entrée served at lunch. Under CMS requirements, what must the facility do?

1. AOffer a substitute of similar nutritive valueCheck

   CMS requires a nursing facility to offer a resident who refuses food a substitute of similar nutritive value that fits the resident's preferences.
2. BServe the same entrée again at dinnerCheck

   Serving the refused entrée again ignores the preference and leaves the lunch meal unreplaced.
3. CReplace the meal with an oral supplementCheck

   An oral supplement is not an automatic stand-in for a meal; the resident is to be offered a food substitute of similar value first.
4. DDocument the refusal and wait until dinnerCheck

   Documenting the refusal and waiting until dinner leaves the resident without lunch, which the requirement does not allow.

A hospital cafeteria groups its customers by how often they buy lunch and whether they use the employee loyalty card, then sends different offers to each group. Which type of market segmentation is this?

1. ADemographicCheck

   Demographic segmentation uses traits such as age, sex, or income, none of which the cafeteria used.
2. BBehavioralCheck

   Grouping customers by how often they buy and whether they use a loyalty card divides them by what they do, which is behavioral segmentation.
3. CPsychographicCheck

   Psychographic segmentation groups people by values, lifestyle, and attitudes, not by their buying patterns.
4. DGeographicCheck

   Geographic segmentation divides a market by location, which plays no part in this grouping.

A long-term care facility serves 450 portions of roasted chicken breast daily, 30 days a month, at 4 oz cooked each. The AP cost is $3.20/lb. If the cooked yield drops from 74% to 70% after a supplier change, how much more will the chicken cost each month?

1. A$833.98Check

   The 3,375 lb of cooked chicken needs 4,560.81 lb AP at 74% yield and 4,821.43 lb at 70%; the extra 260.62 lb at $3.20 adds $833.98 a month.
2. B$27.80Check

   $27.80 is the increase for a single day, while the question asks about the 30-day month.
3. C$583.78Check

   $583.78 takes 4% of the current AP weight, which understates the extra purchase needed at the lower yield.
4. D$432.00Check

   $432.00 multiplies the cooked weight by the 4-point drop in yield instead of recalculating the AP weight at each yield.

A storeroom manager uses ABC analysis. Which items should receive the tightest control, such as perpetual records and locked storage?

1. AItems reordered most often from vendorsCheck

   How often an item is reordered does not define its ABC class, which rests on annual dollar value.
2. BThe few items with most of the dollar valueCheck

   In ABC analysis the A group is a small share of items that holds most of the inventory value, so it gets perpetual records and locked storage.
3. CThe many low-cost items on most shelvesCheck

   The many low-cost items form the C group, which needs only simple controls.
4. DItems with the longest storage shelf lifeCheck

   Shelf life matters for storage planning, but it plays no role in ABC classification.

A recipe for 50 servings uses 2.0 lb of an ingredient, and 230 servings are needed. The ingredient comes only in 10-lb cases at $20.00 per case, none is on hand, and any unused amount will be discarded. What is the extra cost per portion caused by buying a whole case?

1. A$0.087Check

   $0.087 spreads the whole $20 case over 230 portions, which is the full ingredient cost rather than the extra cost.
2. B$1.60Check

   $1.60 is the total cost of the discarded 0.8 lb, not the cost per portion.
3. C$0.00Check

   $0.00 would hold only if the leftover were used later; here the 0.8 lb is thrown away, so buying the whole case does add cost.
4. D$0.007Check

   The recipe needs 2.0 × 230 ÷ 50 = 9.2 lb, so 0.8 lb of the case is discarded; 0.8 lb × $2.00 = $1.60, and $1.60 ÷ 230 is about $0.007 per portion.

A hospital agrees to buy most of its food and supplies from one distributor in exchange for lower prices and consolidated deliveries. This purchasing arrangement is called:

1. APrime vendor purchasingCheck

   In prime vendor purchasing, one distributor supplies most items under a negotiated agreement, which lowers prices and consolidates deliveries.
2. BGroup purchasing organizationCheck

   A group purchasing organization pools many facilities to negotiate prices; it is not one hospital committing to a single distributor.
3. CCost-plus purchasingCheck

   Cost-plus purchasing pays the distributor's cost plus an agreed markup, which is a pricing method rather than a single-supplier arrangement.
4. DFormal competitive biddingCheck

   Formal competitive bidding chooses suppliers contract by contract on sealed bids against written specifications; it does not by itself mean buying most items from one distributor.

In the 2019 Dietary Reference Intakes for sodium, what type of reference value is the adult figure of 2,300 mg per day?

1. AChronic Disease Risk Reduction Intake (CDRR)Check

   The 2019 sodium review set 2,300 mg as the CDRR: reducing intake that is above this level is expected to lower chronic disease risk.
2. BAdequate Intake (AI)Check

   The adult sodium Adequate Intake is 1,500 mg per day, a separate reference value from the 2,300 mg figure.
3. CRecommended Dietary Allowance (RDA)Check

   Evidence was too limited to set an EAR for sodium, and without an EAR there is no RDA.
4. DTolerable Upper Intake Level (UL)Check

   The 2019 review set no Tolerable Upper Intake Level for sodium, because the evidence did not show toxicity; the 2,300 mg value rests on chronic disease risk instead.

A state health department needs annual, state-level estimates of adult obesity prevalence to track trends for program planning. Which data source is most appropriate?

1. ANHISCheck

   NHIS is a national household interview survey designed for national and regional estimates, not dependable yearly figures for every state.
2. BNHANESCheck

   NHANES measures height and weight directly, but its national sample is too small to give estimates for each state.
3. CBRFSSCheck

   BRFSS is an annual state-based telephone survey of adults, so it gives the state-level obesity estimates needed to follow trends.
4. DYRBSSCheck

   YRBSS surveys high school students, so it cannot describe adult obesity.

During an NFPE, a patient with long-standing alcohol use disorder has a dark, scaly rash on the backs of both hands and around the neck, reports diarrhea, and is intermittently confused. Which nutrient deficiency is most likely?

1. AZincCheck

   Zinc deficiency also causes dermatitis, but it centers on the skin around the mouth and other body openings rather than following sun exposure.
2. BThiaminCheck

   Thiamin deficiency explains confusion and Wernicke encephalopathy, but it does not produce a photosensitive rash on the hands and neck.
3. CRiboflavinCheck

   Riboflavin deficiency shows as cracks at the corners of the mouth, a sore magenta tongue, and facial seborrheic dermatitis, not this sun-exposed rash.
4. DNiacinCheck

   A dark, scaly rash on sun-exposed skin with diarrhea and confusion is the classic pattern of pellagra, and alcohol use disorder makes niacin deficiency more likely.

A dietetic intern writes: 'Poor appetite related to malnutrition as evidenced by 6% weight loss in 1 month.' What is the main error in this statement?

1. AThe problem and etiology are reversedCheck

   Poor appetite is the cause and malnutrition is the nutrition problem it leads to, so the problem and etiology have swapped places.
2. BA laboratory value is requiredCheck

   Signs and symptoms may come from any assessment domain; a PES statement does not need a laboratory value.
3. CMalnutrition cannot appear in any PESCheck

   Malnutrition is a standardized nutrition diagnosis term, so it can be the problem in a PES statement.
4. DWeight loss is not a valid signCheck

   Percent weight loss over a stated time is measurable evidence, exactly what the signs part of a PES statement calls for.

An ICU dietitian wants a tool that combines age, APACHE II and SOFA scores, comorbidities and days in hospital before ICU admission to identify ventilated patients most likely to benefit from aggressive feeding. Which tool fits?

1. AMUSTCheck

   MUST screens adults from BMI, recent weight loss, and the effect of acute illness on intake; it uses no ICU severity scores.
2. BMNA-SFCheck

   MNA-SF is a short screen for older adults built on intake, weight loss, mobility, stress, and BMI, not on APACHE II or SOFA.
3. CNUTRICCheck

   The NUTRIC score combines age, APACHE II, SOFA, comorbidities, and days in hospital before ICU admission to flag ventilated patients most likely to benefit from aggressive feeding.
4. DMSTCheck

   MST asks only about recent weight loss and appetite, so it cannot weigh illness severity in ventilated patients.

A menu engineering analysis shows that a cafeteria entrée sells in high volume but has a low contribution margin. What action is most appropriate for this item?

1. ARemove it and replace it with a new entréeCheck

   Removing it for a new entrée is the move for dogs, items low in both popularity and margin; dropping a top seller gives up its volume.
2. BGive it a more prominent menu positionCheck

   Prime menu placement is used to sell more high-margin puzzles; it would push even more sales of a low-margin item.
3. CPromote it with table tentsCheck

   Table-tent promotion suits items that earn well but sell poorly, and this entrée already sells in high volume.
4. DRaise its price or cut its plate costCheck

   A high-volume, low-margin item is a plowhorse: guests already buy it, so a careful price increase or a lower plate cost lifts its margin while keeping the volume.