Txst nutrition 2360 exam with 100% correct answers
1. A researcher is investigating the effect of a high-fructose diet on hepatic de novo lipogenesis.
Which of the following metabolic intermediates directly activates the transcription factor ChREBP,
leading to increased expression of glycolytic and lipogenic enzymes?
A. Fructose-1-phosphate
B. Xylulose-5-phosphate
C. Fructose-2,6-bisphosphate
D. Glucose-6-phosphate
Answer: B
Rationale: Xylulose-5-phosphate is a metabolite produced in the pentose phosphate pathway that
activates protein phosphatase 2A, which dephosphorylates and activates ChREBP. Fructose-1-phosphate
is involved in fructolysis but does not directly activate ChREBP. Fructose-2,6-bisphosphate regulates
glycolysis/gluconeogenesis via PFK-2/FBPase-2, and glucose-6-phosphate is a substrate for glycogen
synthesis or the pentose phosphate pathway.
2. In a patient with suspected vitamin B12 deficiency, which combination of laboratory findings is
most indicative of pernicious anemia rather than dietary deficiency?
A. Elevated homocysteine, normal methylmalonic acid, positive intrinsic factor antibodies
B. Elevated homocysteine and methylmalonic acid, positive parietal cell antibodies
C. Elevated homocysteine, elevated methylmalonic acid, normal Schilling test
D. Normal homocysteine, elevated methylmalonic acid, negative intrinsic factor antibodies
Answer: B
Rationale: Pernicious anemia is an autoimmune condition with antibodies against intrinsic factor or
parietal cells, leading to B12 malabsorption. Both homocysteine and methylmalonic acid are elevated in
B12 deficiency because B12 is a cofactor for methionine synthase and methylmalonyl-CoA mutase. In
dietary deficiency, the Schilling test may be abnormal, but pernicious anemia typically shows abnormal
Schilling test corrected with intrinsic factor. Option A has normal MMA, which is inconsistent with B12
deficiency. Option C with normal Schilling test is not typical for pernicious anemia. Option D with
normal homocysteine suggests folate deficiency rather than B12.
3. A 45-year-old male with type 2 diabetes mellitus and chronic kidney disease (stage 3) is being
evaluated for protein requirements. His estimated glomerular filtration rate (eGFR) is 45
mL/min/1.73 m². Which of the following protein intake recommendations aligns with current
evidence-based guidelines for this patient to slow progression of nephropathy?
A. 0.8 g/kg body weight per day
B. 1.2 g/kg body weight per day
C. 0.6 g/kg body weight per day with ketoacid analogs
D. 1.5 g/kg body weight per day to prevent sarcopenia
Page 1
,Answer: A
Rationale: For patients with diabetic kidney disease (stage 3), the KDIGO guidelines recommend a
protein intake of 0.8 g/kg/day to reduce progression. Higher intakes (1.2-1.5 g/kg) may increase
glomerular hyperfiltration and accelerate decline. Very low protein diets (0.6 g/kg) with ketoacid
analogs are reserved for advanced stages (stage 4-5) under strict supervision. The goal is to balance
nephroprotection with adequacy.
4. Which of the following dietary patterns has been most consistently associated with a reduced
risk of colorectal adenoma recurrence in randomized controlled trials?
A. Low-fat, high-carbohydrate diet
B. Mediterranean diet supplemented with mixed nuts
C. High-fiber, low-fat diet with increased fruits and vegetables
D. Low-carbohydrate, high-protein diet
Answer: C
Rationale: The Polyp Prevention Trial and other RCTs have shown that a diet low in fat, high in fiber,
and rich in fruits and vegetables reduces the risk of colorectal adenoma recurrence. The Mediterranean
diet has been associated with reduced cancer risk in observational studies but not specifically in RCTs
for adenoma recurrence. Low-fat high-carbohydrate diets without emphasis on fiber are less effective.
Low-carbohydrate high-protein diets have not shown benefit and may increase risk due to reduced fiber
intake.
5. A patient with Crohn's disease has a stricture in the terminal ileum. Which of the following
nutrition interventions is most appropriate to minimize obstructive symptoms while maintaining
nutritional status?
A. Elemental diet via nasogastric tube
B. Low-residue diet with small, frequent meals
C. High-fiber diet with increased fluid intake
D. Total parenteral nutrition with bowel rest
Answer: B
Rationale: In the presence of a stricture, a low-residue diet reduces fecal bulk and decreases the risk of
obstruction. Small, frequent meals ease digestive load. An elemental diet may be used in acute flares but
is not necessary for chronic management and is less palatable. High-fiber diet would exacerbate
obstruction. TPN with bowel rest is reserved for severe cases or preoperative preparation, not as
first-line management.
6. A researcher is analyzing data from a cohort study examining the association between dietary
glycemic load (GL) and incident type 2 diabetes. Which of the following statistical methods is most
appropriate to adjust for confounding by energy intake?
A. Stratified analysis by quartiles of energy intake
B. Inclusion of total energy intake as a covariate in a multivariable model
C. Use of the residual method to compute energy-adjusted GL
D. Restriction of the analysis to participants with energy intake within a narrow range
Page 2
,Answer: C
Rationale: The residual method (Willett's method) is the standard approach to adjust nutrient intake for
total energy, as it removes variation due to energy intake and reduces confounding. Including energy as
a covariate can also adjust, but it may introduce collinearity and is less effective when the nutrient is
highly correlated with energy. Stratification and restriction reduce sample size and may not fully control
confounding.
7. Which of the following best describes the role of the gut microbiota in the metabolism of dietary
choline and its association with cardiovascular disease risk?
A. Gut bacteria convert choline to trimethylamine (TMA), which is absorbed and oxidized in the liver to
trimethylamine N-oxide (TMAO), promoting atherosclerosis.
B. Gut bacteria synthesize choline from dietary precursors, increasing plasma choline levels and reducing
homocysteine.
C. Gut bacteria degrade choline to betaine, which lowers blood pressure and reduces stroke risk.
D. Gut bacteria ferment choline to short-chain fatty acids, which improve lipid profiles and reduce
inflammation.
Answer: A
Rationale: Choline is metabolized by gut microbiota to TMA, which is then oxidized in the liver to TMAO.
Elevated TMAO levels are associated with increased cardiovascular risk. Option B is incorrect because
bacteria do not synthesize choline; they produce TMA. Option C: betaine is produced in the liver, not by
bacteria. Option D: SCFAs are from fiber fermentation, not choline.
8. A 30-year-old female with a BMI of 17.5 kg/m² and amenorrhea for 6 months is diagnosed with
anorexia nervosa. Her serum phosphorus level is 2.1 mg/dL (normal: 2.5-4.5). Which of the
following is the most important consideration when initiating refeeding?
A. Start with a high-calorie diet (>2000 kcal/day) to correct malnutrition rapidly
B. Begin with 1000-1200 kcal/day and monitor phosphorus levels closely for refeeding syndrome
C. Administer intravenous phosphorus supplementation before starting oral feeds
D. Use a high-protein, low-carbohydrate formula to minimize insulin surge
Answer: B
Rationale: Patients with severe malnutrition are at high risk for refeeding syndrome, characterized by
hypophosphatemia, hypokalemia, and hypomagnesemia. Starting with low caloric intake (1000-1200
kcal/day) and close monitoring of electrolytes is standard. High-calorie initiation increases risk. IV
phosphorus is given only if severe hypophosphatemia develops. High-protein, low-carbohydrate does not
prevent refeeding syndrome; the key is gradual caloric increase.
9. A clinical trial investigates the effect of omega-3 fatty acid supplementation (EPA+DHA 4 g/day)
on triglyceride levels in patients with hypertriglyceridemia. Which of the following mechanisms
best explains the triglyceride-lowering effect of high-dose omega-3s?
A. Increased expression of lipoprotein lipase, enhancing VLDL clearance
B. Reduced hepatic secretion of VLDL by decreasing lipogenesis and increasing beta-oxidation
C. Inhibition of cholesterol absorption in the small intestine
D. Upregulation of LDL receptor expression, increasing LDL clearance
Page 3
, Answer: B
Rationale: High-dose omega-3 fatty acids reduce hepatic VLDL production by decreasing the availability
of free fatty acids for triglyceride synthesis and by increasing peroxisomal beta-oxidation. They also
suppress the expression of lipogenic genes. Lipoprotein lipase activity is not directly increased; in fact,
omega-3s may reduce postprandial lipemia by other mechanisms. They do not inhibit cholesterol
absorption (that is ezetimibe) and do not upregulate LDL receptors.
10. Which of the following best explains why the Dietary Guidelines for Americans, 2020-2025,
recommend limiting added sugars to less than 10% of total daily calories, rather than a specific
gram amount?
A. A percentage-based recommendation is easier to remember for the general public.
B. The adverse health effects of added sugars are dose-dependent and independent of total caloric intake.
C. A relative recommendation allows flexibility across different energy needs and prevents excessive intake
relative to energy requirements.
D. The evidence base for a specific gram threshold is insufficient due to lack of randomized controlled trials.
Answer: C
Rationale: Using a percentage of total calories ensures that the recommendation scales appropriately for
individuals with varying energy needs, preventing both under- and overconsumption relative to energy
requirements. Option A is plausible but not the primary scientific rationale. Option B is incorrect
because adverse effects are related to both absolute amount and caloric context. Option D is false; there
is sufficient evidence, but the percentage approach is more practical.
11. A patient with chronic kidney disease (CKD) stage 4 is prescribed a renal diet. Which of the
following meal plans best aligns with the current evidence-based nutritional management for this
condition, considering the need to delay dialysis and manage metabolic acidosis?
A. High protein (1.5 g/kg/day), low potassium, low phosphorus, and sodium restriction
B. Moderate protein (0.6-0.8 g/kg/day), low potassium, low phosphorus, and sodium restriction, with
bicarbonate supplementation if needed
C. Low protein (0.3 g/kg/day) with ketoacid analogs, liberal potassium, and high phosphorus
D. High protein (1.2 g/kg/day), liberal potassium, low phosphorus, and no sodium restriction
Answer: B
Rationale: For CKD stage 4, moderate protein restriction (0.6-0.8 g/kg/day) is recommended to reduce
uremic toxin load and delay dialysis, along with restricted potassium, phosphorus, and sodium to
manage complications. Bicarbonate may be added for metabolic acidosis. Option A is too high in
protein; C is too restrictive and includes liberal potassium; D is inappropriate for CKD.
12. A recent meta-analysis of randomized controlled trials examined the effect of n-3
polyunsaturated fatty acid (PUFA) supplementation on cardiovascular outcomes in patients with
established coronary heart disease. Which of the following findings best represents the current
consensus based on the highest quality evidence?
A. High-dose EPA (4 g/day) significantly reduces major adverse cardiovascular events, but DHA shows no
benefit
B. Combined EPA and DHA (1 g/day) reduces all-cause mortality in primary prevention
Page 4
1. A researcher is investigating the effect of a high-fructose diet on hepatic de novo lipogenesis.
Which of the following metabolic intermediates directly activates the transcription factor ChREBP,
leading to increased expression of glycolytic and lipogenic enzymes?
A. Fructose-1-phosphate
B. Xylulose-5-phosphate
C. Fructose-2,6-bisphosphate
D. Glucose-6-phosphate
Answer: B
Rationale: Xylulose-5-phosphate is a metabolite produced in the pentose phosphate pathway that
activates protein phosphatase 2A, which dephosphorylates and activates ChREBP. Fructose-1-phosphate
is involved in fructolysis but does not directly activate ChREBP. Fructose-2,6-bisphosphate regulates
glycolysis/gluconeogenesis via PFK-2/FBPase-2, and glucose-6-phosphate is a substrate for glycogen
synthesis or the pentose phosphate pathway.
2. In a patient with suspected vitamin B12 deficiency, which combination of laboratory findings is
most indicative of pernicious anemia rather than dietary deficiency?
A. Elevated homocysteine, normal methylmalonic acid, positive intrinsic factor antibodies
B. Elevated homocysteine and methylmalonic acid, positive parietal cell antibodies
C. Elevated homocysteine, elevated methylmalonic acid, normal Schilling test
D. Normal homocysteine, elevated methylmalonic acid, negative intrinsic factor antibodies
Answer: B
Rationale: Pernicious anemia is an autoimmune condition with antibodies against intrinsic factor or
parietal cells, leading to B12 malabsorption. Both homocysteine and methylmalonic acid are elevated in
B12 deficiency because B12 is a cofactor for methionine synthase and methylmalonyl-CoA mutase. In
dietary deficiency, the Schilling test may be abnormal, but pernicious anemia typically shows abnormal
Schilling test corrected with intrinsic factor. Option A has normal MMA, which is inconsistent with B12
deficiency. Option C with normal Schilling test is not typical for pernicious anemia. Option D with
normal homocysteine suggests folate deficiency rather than B12.
3. A 45-year-old male with type 2 diabetes mellitus and chronic kidney disease (stage 3) is being
evaluated for protein requirements. His estimated glomerular filtration rate (eGFR) is 45
mL/min/1.73 m². Which of the following protein intake recommendations aligns with current
evidence-based guidelines for this patient to slow progression of nephropathy?
A. 0.8 g/kg body weight per day
B. 1.2 g/kg body weight per day
C. 0.6 g/kg body weight per day with ketoacid analogs
D. 1.5 g/kg body weight per day to prevent sarcopenia
Page 1
,Answer: A
Rationale: For patients with diabetic kidney disease (stage 3), the KDIGO guidelines recommend a
protein intake of 0.8 g/kg/day to reduce progression. Higher intakes (1.2-1.5 g/kg) may increase
glomerular hyperfiltration and accelerate decline. Very low protein diets (0.6 g/kg) with ketoacid
analogs are reserved for advanced stages (stage 4-5) under strict supervision. The goal is to balance
nephroprotection with adequacy.
4. Which of the following dietary patterns has been most consistently associated with a reduced
risk of colorectal adenoma recurrence in randomized controlled trials?
A. Low-fat, high-carbohydrate diet
B. Mediterranean diet supplemented with mixed nuts
C. High-fiber, low-fat diet with increased fruits and vegetables
D. Low-carbohydrate, high-protein diet
Answer: C
Rationale: The Polyp Prevention Trial and other RCTs have shown that a diet low in fat, high in fiber,
and rich in fruits and vegetables reduces the risk of colorectal adenoma recurrence. The Mediterranean
diet has been associated with reduced cancer risk in observational studies but not specifically in RCTs
for adenoma recurrence. Low-fat high-carbohydrate diets without emphasis on fiber are less effective.
Low-carbohydrate high-protein diets have not shown benefit and may increase risk due to reduced fiber
intake.
5. A patient with Crohn's disease has a stricture in the terminal ileum. Which of the following
nutrition interventions is most appropriate to minimize obstructive symptoms while maintaining
nutritional status?
A. Elemental diet via nasogastric tube
B. Low-residue diet with small, frequent meals
C. High-fiber diet with increased fluid intake
D. Total parenteral nutrition with bowel rest
Answer: B
Rationale: In the presence of a stricture, a low-residue diet reduces fecal bulk and decreases the risk of
obstruction. Small, frequent meals ease digestive load. An elemental diet may be used in acute flares but
is not necessary for chronic management and is less palatable. High-fiber diet would exacerbate
obstruction. TPN with bowel rest is reserved for severe cases or preoperative preparation, not as
first-line management.
6. A researcher is analyzing data from a cohort study examining the association between dietary
glycemic load (GL) and incident type 2 diabetes. Which of the following statistical methods is most
appropriate to adjust for confounding by energy intake?
A. Stratified analysis by quartiles of energy intake
B. Inclusion of total energy intake as a covariate in a multivariable model
C. Use of the residual method to compute energy-adjusted GL
D. Restriction of the analysis to participants with energy intake within a narrow range
Page 2
,Answer: C
Rationale: The residual method (Willett's method) is the standard approach to adjust nutrient intake for
total energy, as it removes variation due to energy intake and reduces confounding. Including energy as
a covariate can also adjust, but it may introduce collinearity and is less effective when the nutrient is
highly correlated with energy. Stratification and restriction reduce sample size and may not fully control
confounding.
7. Which of the following best describes the role of the gut microbiota in the metabolism of dietary
choline and its association with cardiovascular disease risk?
A. Gut bacteria convert choline to trimethylamine (TMA), which is absorbed and oxidized in the liver to
trimethylamine N-oxide (TMAO), promoting atherosclerosis.
B. Gut bacteria synthesize choline from dietary precursors, increasing plasma choline levels and reducing
homocysteine.
C. Gut bacteria degrade choline to betaine, which lowers blood pressure and reduces stroke risk.
D. Gut bacteria ferment choline to short-chain fatty acids, which improve lipid profiles and reduce
inflammation.
Answer: A
Rationale: Choline is metabolized by gut microbiota to TMA, which is then oxidized in the liver to TMAO.
Elevated TMAO levels are associated with increased cardiovascular risk. Option B is incorrect because
bacteria do not synthesize choline; they produce TMA. Option C: betaine is produced in the liver, not by
bacteria. Option D: SCFAs are from fiber fermentation, not choline.
8. A 30-year-old female with a BMI of 17.5 kg/m² and amenorrhea for 6 months is diagnosed with
anorexia nervosa. Her serum phosphorus level is 2.1 mg/dL (normal: 2.5-4.5). Which of the
following is the most important consideration when initiating refeeding?
A. Start with a high-calorie diet (>2000 kcal/day) to correct malnutrition rapidly
B. Begin with 1000-1200 kcal/day and monitor phosphorus levels closely for refeeding syndrome
C. Administer intravenous phosphorus supplementation before starting oral feeds
D. Use a high-protein, low-carbohydrate formula to minimize insulin surge
Answer: B
Rationale: Patients with severe malnutrition are at high risk for refeeding syndrome, characterized by
hypophosphatemia, hypokalemia, and hypomagnesemia. Starting with low caloric intake (1000-1200
kcal/day) and close monitoring of electrolytes is standard. High-calorie initiation increases risk. IV
phosphorus is given only if severe hypophosphatemia develops. High-protein, low-carbohydrate does not
prevent refeeding syndrome; the key is gradual caloric increase.
9. A clinical trial investigates the effect of omega-3 fatty acid supplementation (EPA+DHA 4 g/day)
on triglyceride levels in patients with hypertriglyceridemia. Which of the following mechanisms
best explains the triglyceride-lowering effect of high-dose omega-3s?
A. Increased expression of lipoprotein lipase, enhancing VLDL clearance
B. Reduced hepatic secretion of VLDL by decreasing lipogenesis and increasing beta-oxidation
C. Inhibition of cholesterol absorption in the small intestine
D. Upregulation of LDL receptor expression, increasing LDL clearance
Page 3
, Answer: B
Rationale: High-dose omega-3 fatty acids reduce hepatic VLDL production by decreasing the availability
of free fatty acids for triglyceride synthesis and by increasing peroxisomal beta-oxidation. They also
suppress the expression of lipogenic genes. Lipoprotein lipase activity is not directly increased; in fact,
omega-3s may reduce postprandial lipemia by other mechanisms. They do not inhibit cholesterol
absorption (that is ezetimibe) and do not upregulate LDL receptors.
10. Which of the following best explains why the Dietary Guidelines for Americans, 2020-2025,
recommend limiting added sugars to less than 10% of total daily calories, rather than a specific
gram amount?
A. A percentage-based recommendation is easier to remember for the general public.
B. The adverse health effects of added sugars are dose-dependent and independent of total caloric intake.
C. A relative recommendation allows flexibility across different energy needs and prevents excessive intake
relative to energy requirements.
D. The evidence base for a specific gram threshold is insufficient due to lack of randomized controlled trials.
Answer: C
Rationale: Using a percentage of total calories ensures that the recommendation scales appropriately for
individuals with varying energy needs, preventing both under- and overconsumption relative to energy
requirements. Option A is plausible but not the primary scientific rationale. Option B is incorrect
because adverse effects are related to both absolute amount and caloric context. Option D is false; there
is sufficient evidence, but the percentage approach is more practical.
11. A patient with chronic kidney disease (CKD) stage 4 is prescribed a renal diet. Which of the
following meal plans best aligns with the current evidence-based nutritional management for this
condition, considering the need to delay dialysis and manage metabolic acidosis?
A. High protein (1.5 g/kg/day), low potassium, low phosphorus, and sodium restriction
B. Moderate protein (0.6-0.8 g/kg/day), low potassium, low phosphorus, and sodium restriction, with
bicarbonate supplementation if needed
C. Low protein (0.3 g/kg/day) with ketoacid analogs, liberal potassium, and high phosphorus
D. High protein (1.2 g/kg/day), liberal potassium, low phosphorus, and no sodium restriction
Answer: B
Rationale: For CKD stage 4, moderate protein restriction (0.6-0.8 g/kg/day) is recommended to reduce
uremic toxin load and delay dialysis, along with restricted potassium, phosphorus, and sodium to
manage complications. Bicarbonate may be added for metabolic acidosis. Option A is too high in
protein; C is too restrictive and includes liberal potassium; D is inappropriate for CKD.
12. A recent meta-analysis of randomized controlled trials examined the effect of n-3
polyunsaturated fatty acid (PUFA) supplementation on cardiovascular outcomes in patients with
established coronary heart disease. Which of the following findings best represents the current
consensus based on the highest quality evidence?
A. High-dose EPA (4 g/day) significantly reduces major adverse cardiovascular events, but DHA shows no
benefit
B. Combined EPA and DHA (1 g/day) reduces all-cause mortality in primary prevention
Page 4
