ISSA Macronutrients & Micronutrients Essentials 3

Question 1

The thermic effect of food (TEF) is highest for which macronutrient?

Accepted Answer

Protein

Answer

Protein has the highest TEF at approximately 20–30%, compared to carbohydrates (5–10%) and fats (0–3%), because protein metabolism requires more energy.

Question 2

Scurvy results from a deficiency of which vitamin due to its role in collagen synthesis?

Accepted Answer

Vitamin C

Answer

Vitamin C (ascorbic acid) is required for hydroxylation of proline and lysine residues in collagen, and its deficiency causes scurvy.

Question 3

Which type of dietary fiber is most effective at lowering LDL cholesterol by binding bile acids in the gut?

Accepted Answer

Soluble fiber

Answer

Soluble fiber (e.g., beta-glucan, pectin) forms a viscous gel in the intestine that traps bile acids, increasing their fecal excretion and reducing LDL cholesterol.

Question 4

An athlete following a ketogenic diet would be relying primarily on which metabolic substrate for energy during rest and low-intensity exercise?

Accepted Answer

Ketone bodies derived from fat oxidation

Answer

During ketosis, the liver produces ketone bodies (acetoacetate, beta-hydroxybutyrate) from fatty acid oxidation, which become the primary fuel when carbohydrate intake is severely restricted.

Question 5

Iron absorption from plant-based (non-heme) sources is significantly enhanced by consuming which nutrient simultaneously?

Accepted Answer

Vitamin C

Answer

Vitamin C reduces ferric iron (Fe³⁺) to ferrous iron (Fe²⁺), the form that is more readily absorbed by intestinal enterocytes, enhancing non-heme iron absorption.

(ISSA) International Sports Sciences Association Certified Nutritionist Practice Test

(ISSA) International Sports Sciences Association Certified Nutritionist Practice Test

ISSA Macronutrients & Micronutrients Essentials 3