Download [CBNS] CBNS Certifyingination Certification Exam Guide and more Exams Technology in PDF only on Docsity!
Exam Guide
Question 1. Which macronutrient provides the highest caloric value per gram? A) Protein B) Carbohydrate C) Fat D) Alcohol Answer: C Explanation: Fat supplies ~9 kcal/g, whereas protein and carbohydrate each provide ~4 kcal/g; alcohol provides ~7 kcal/g. Question 2. The primary site of dietary carbohydrate absorption is the: A) Stomach B) Duodenum C) Jejunum D) Ileum Answer: C Explanation: Monosaccharides are absorbed mainly in the jejunum via sodium‑glucose transporters. Question 3. Which vitamin functions as a co‑factor for the enzyme pyruvate dehydrogenase? A) Vitamin B1 (thiamine) B) Vitamin B2 (riboflavin) C) Vitamin B3 (niacin) D) Vitamin B5 (pantothenic acid) Answer: A
Exam Guide
Explanation: Thiamine pyrophosphate is the essential co‑factor for pyruvate dehydrogenase, linking glycolysis to the TCA cycle. Question 4. The rate‑limiting enzyme of cholesterol synthesis is: A) HMG‑CoA reductase B) Acetyl‑CoA carboxylase C) Fatty acid synthase D) LDL receptor Answer: A Explanation: HMG‑CoA reductase controls the conversion of HMG‑CoA to mevalonate, the first committed step in cholesterol biosynthesis. Question 5. Which of the following minerals is the primary intracellular cation? A) Sodium B) Calcium C) Potassium D) Magnesium Answer: C Explanation: Potassium is the main intracellular positively charged ion, crucial for membrane potential and enzyme activation. Question 6. The primary function of the large intestine is to: A) Digest proteins B) Absorb water and electrolytes C) Secrete pancreatic enzymes D) Produce bile
Exam Guide
D) Phase III transport Answer: C Explanation: Phase II reactions attach polar groups (e.g., glucuronide, sulfate) to increase solubility for excretion. Question 10. Nutrigenomics primarily investigates: A) How diet influences gene expression B) Genetic mutations causing malabsorption C) The microbiome’s role in obesity D) Vitamin supplementation in pregnancy Answer: A Explanation: Nutrigenomics studies how nutrients modulate gene expression and epigenetic mechanisms. Question 11. The thermic effect of food (TEF) is greatest for which macronutrient? A) Fat B) Carbohydrate C) Protein D) Alcohol Answer: C Explanation: Protein has the highest TEF (~20‑30% of its calories) due to higher metabolic cost of digestion and synthesis. Question 12. Which hormone is the primary regulator of basal metabolic rate? A) Insulin B) Thyroxine (T4)
Exam Guide
C) Cortisol D) Leptin Answer: B Explanation: Thyroid hormones increase basal metabolic rate by stimulating mitochondrial activity. Question 13. During prolonged fasting, the primary source of glucose for the brain is: A) Glycogenolysis B) Gluconeogenesis from lactate C) Gluconeogenesis from glycerol D) Ketone bodies Answer: D Explanation: After ~3 days of fasting, the brain derives up to 60% of its energy from ketone bodies (β‑hydroxybutyrate, acetoacetate). Question 14. Which amino acid is strictly ketogenic? A) Leucine B) Phenylalanine C) Lysine D) Both A and C Answer: D Explanation: Leucine and lysine are purely ketogenic, yielding acetyl‑CoA or acetoacetate during catabolism. Question 15. The primary transporter for glucose uptake in skeletal muscle during exercise is:
Exam Guide
Question 18. Which of the following is a water‑soluble vitamin that also acts as a co‑enzyme in the citric acid cycle? A) Vitamin B1 (thiamine) B) Vitamin B2 (riboflavin) C) Vitamin B3 (niacin) D) Vitamin B5 (pantothenic acid) Answer: D Explanation: Pantothenic acid is a component of coenzyme A, pivotal for the TCA cycle. Question 19. The primary function of soluble dietary fiber is to: A) Increase stool bulk B) Bind bile acids and lower cholesterol C) Provide fermentable substrate for gut bacteria D) Reduce mineral absorption Answer: C Explanation: Soluble fiber is fermented by colonic microbes, producing short‑chain fatty acids and supporting gut health. Question 20. Which phytochemical class is characterized by a flavone backbone and is linked to reduced cardiovascular risk? A) Carotenoids B) Isoflavones C) Flavonoids D) Polyphenols Answer: C
Exam Guide
Explanation: Flavonoids (e.g., quercetin, catechins) have antioxidant and vasodilatory effects that lower CVD risk. Question 21. The Recommended Dietary Allowance (RDA) for calcium for adults aged 19‑ 50 is: A) 800 mg/day B) 1000 mg/day C) 1200 mg/day D) 1500 mg/day Answer: B Explanation: The RDA for calcium in this age group is 1000 mg per day to support bone health. Question 22. Which supplement is contraindicated in patients with hemochromatosis due to risk of iron overload? A) Vitamin C B) Calcium carbonate C) Magnesium oxide D) Zinc gluconate Answer: A Explanation: Vitamin C enhances non‑heme iron absorption, potentially worsening iron overload. Question 23. The “first‑pass effect” refers to: A) Gastric emptying rate B) Hepatic metabolism of orally administered compounds before systemic circulation C) Renal excretion of water‑soluble vitamins
Exam Guide
A) BMI calculation B) Skinfold thickness C) Dual‑energy X‑ray absorptiometry (DEXA) D) Bioelectrical impedance analysis (BIA) Answer: C Explanation: DEXA provides precise measurements of fat mass, lean mass, and bone mineral density. Question 27. Which anthropometric measure best predicts visceral adiposity? A) BMI B) Waist circumference C) Hip circumference D) Mid‑upper arm circumference Answer: B Explanation: Waist circumference correlates strongly with intra‑abdominal fat. Question 28. A fasting plasma glucose of 126 mg/dL on two separate occasions indicates: A) Impaired fasting glucose B) Type 1 diabetes mellitus C) Type 2 diabetes mellitus D) Prediabetes Answer: C Explanation: A fasting glucose ≥126 mg/dL on two occasions meets diagnostic criteria for diabetes. Question 29. Which laboratory marker is most specific for iron deficiency anemia?
Exam Guide
A) Serum ferritin B) Hemoglobin C) Mean corpuscular volume (MCV) D) Total iron‑binding capacity (TIBC) Answer: A Explanation: Low ferritin reflects depleted iron stores and is the most specific indicator. Question 30. The presence of increased urinary ketones in a patient on a low‑carbohydrate diet primarily reflects: A) Ketoacidosis B) Physiologic ketosis C. Renal failure D) Hyperglycemia Answer: B Explanation: Nutritional ketosis is a benign elevation of ketones due to carbohydrate restriction, not an acidotic state. Question 31. Which functional test evaluates mitochondrial oxidative capacity through measurement of organic acids? A) Serum lactate B) Urine organic acid profile C) Salivary cortisol D) Stool calprotectin Answer: B Explanation: The urine organic acid test detects intermediates of the TCA cycle, indicating mitochondrial function.
Exam Guide
Explanation: MI uses empathetic, client‑centered communication to resolve ambivalence and promote self‑motivated change. Question 35. Which dietary pattern has the strongest evidence for reducing the risk of coronary heart disease? A) Low‑fat, high‑carbohydrate diet B) Mediterranean diet C) High‑protein, low‑carbohydrate diet D) Ketogenic diet Answer: B Explanation: The Mediterranean pattern, rich in fruits, vegetables, whole grains, olive oil, and fish, consistently shows cardioprotective effects. Question 36. In type 1 diabetes, the primary defect is: A) Insulin resistance B) Autoimmune destruction of pancreatic β‑cells C) Impaired glucagon secretion D. Excess hepatic glucose production Answer: B Explanation: Autoimmune-mediated loss of β‑cells leads to absolute insulin deficiency. Question 37. The glycemic index (GI) of a food is determined by: A) Its total carbohydrate content B) The rate at which it raises blood glucose relative to glucose C) Its fiber content alone D) The presence of fructose
Exam Guide
Answer: B Explanation: GI compares the post‑prandial glucose response of a test food to that of pure glucose. Question 38. Which dietary component most effectively lowers LDL‑cholesterol? A) Saturated fat B) Trans fat C) Soluble fiber D) Cholesterol Answer: C Explanation: Soluble fiber binds bile acids, reducing cholesterol reabsorption and lowering LDL. Question 39. In patients with chronic kidney disease (stage 3), protein intake should be: A) >1.5 g/kg body weight B) 0.8–1.0 g/kg body weight C) 0.6–0.8 g/kg body weight D) No restriction needed Answer: C Explanation: Moderately reduced protein (0.6–0.8 g/kg) helps limit nitrogenous waste while preserving lean mass. Question 40. Which micronutrient is essential for the synthesis of the neurotransmitter serotonin? A) Vitamin B B) Folate C) Magnesium
Exam Guide
D) High‑fiber diet Answer: B Explanation: Purine metabolism generates uric acid; excess intake raises serum urate, precipitating gout. Question 44. In inflammatory bowel disease, exclusive enteral nutrition (EEN) is most commonly used for: A) Inducing remission in Crohn’s disease B) Managing ulcerative colitis flare-ups C) Treating IBS symptoms D) Preventing colon cancer Answer: A Explanation: EEN can induce remission in pediatric Crohn’s disease and improve mucosal healing. Question 45. Which dietary factor is most strongly linked to the development of iron‑deficiency anemia in women of reproductive age? A) High calcium intake B) Low intake of heme iron C) Excess vitamin C D) High phytate consumption Answer: B Explanation: Women often consume less heme iron; lower bioavailability contributes to deficiency. Question 46. The Dietary Reference Intake (DRI) term that represents the intake sufficient to meet the needs of 97‑98% of a population is:
Exam Guide
A) RDA
B) AI
C) UL
D) EAR
Answer: A Explanation: The Recommended Dietary Allowance (RDA) is set to cover the needs of nearly all healthy individuals. Question 47. Which of the following is a recognized adverse effect of chronic excessive vitamin D supplementation? A) Hypercalcemia B. Hypophosphatemia C) Vitamin K deficiency D. Iron overload Answer: A Explanation: Excess vitamin D increases intestinal calcium absorption, leading to hypercalcemia. Question 48. The term “bioavailability” refers to: A) The total amount of a nutrient in food B) The proportion of an ingested nutrient that is absorbed and utilized C. The rate of digestion D) The stability of a nutrient during cooking Answer: B Explanation: Bioavailability encompasses absorption, transport, metabolism, and utilization of a nutrient.
Exam Guide
Explanation: Chronic lead exposure raises blood pressure through renal and vascular mechanisms. Question 52. The primary purpose of the Food Safety Modernization Act (FSMA) is to: A) Increase import tariffs on unsafe foods B) Shift focus from responding to contamination to preventing it C) Ban all genetically modified organisms D) Standardize nutritional labeling Answer: B Explanation: FSMA emphasizes preventive controls throughout the food supply chain. Question 53. Which population group is at highest risk for iodine deficiency? A) Adult men in the United States B) Pregnant women in regions with low iodized salt use C. Elderly individuals consuming high‑protein diets D) Adolescents with high dairy intake Answer: B Explanation: Pregnancy increases iodine requirements; inadequate iodized salt intake predisposes to deficiency. Question 54. The term “food insecurity” is defined as: A) Lack of access to any food at all B. Limited or uncertain availability of nutritionally adequate foods C) Preference for processed foods over fresh produce D) Overconsumption of calories leading to obesity Answer: B
Exam Guide
Explanation: Food insecurity reflects insufficient resources to obtain healthy, safe foods. Question 55. Which of the following best describes the concept of “cultural competency” in nutrition practice? A) Providing the same diet plan to all clients B) Adapting assessments and recommendations to respect cultural beliefs and practices C) Using only evidence‑based guidelines regardless of client background D) Avoiding discussion of cultural food traditions Answer: B Explanation: Cultural competency involves recognizing and integrating cultural influences into care. Question 56. HIPAA primarily protects: A) Intellectual property of nutrition research B) Patient health information privacy C. Food labeling standards D) Professional licensure requirements Answer: B Explanation: The Health Insurance Portability and Accountability Act safeguards personal health information. Question 57. Which of the following is an example of a conflict of interest that must be disclosed under the BCNS Code of Ethics? A) Attending a professional conference B. Receiving research funding from a supplement manufacturer whose products you recommend C) Using standard clinical forms
