Nutrition Questions and Answers

Correct answer: How rapidly it raises blood glucose relative to a reference food. Glycaemic index ranks carbohydrate-containing foods by their post-meal blood-glucose response relative to a standard reference. It is affected by processing, cooking, fibre, fat, protein and food structure; glycaemic load also incorporates the amount of carbohydrate eaten. It does not directly measure vitamins, protein quality or water content.

Correct answer: Soluble viscous fibre. Soluble viscous fibres such as beta-glucan and psyllium can lower LDL cholesterol by influencing bile-acid reabsorption and hepatic cholesterol metabolism. They may also slow gastric emptying and glucose absorption, whereas insoluble fibre is especially useful for stool bulk. Animal protein is not fibre, trans fat worsens cardiovascular risk and 'insoluble mineral fibre' is not the relevant nutritional category.

Correct answer: A substrate selectively used by beneficial microorganisms. A prebiotic is a substrate selectively utilized by host microorganisms that confers a health benefit. A live culture is a probiotic, antibiotics suppress susceptible microbes and complete protein concerns amino-acid composition.

Correct answer: A live microorganism that may confer a health benefit when adequately consumed. Probiotics are live microorganisms that, when administered in adequate amounts, may confer a health benefit on the host. Effects are strain-specific and condition-specific; not every fermented food or bacterial product has proven probiotic benefit. Indigestible substrates are prebiotics, vitamins are chemical nutrients and harmful contaminants are not probiotics.

Correct answer: Glucose promotes sodium and water absorption in the intestine. ORS works through sodium–glucose cotransport in the small intestine, allowing sodium and water to be absorbed even during many diarrhoeal illnesses. The correct balance of glucose and electrolytes is crucial; overly concentrated sugary drinks can worsen osmotic diarrhoea. ORS does not paralyse the intestine, normally contains no antibiotic and does not replace blood cells. A good solution identifies the key physiological clue and then checks every option against established nutritional science.

Correct answer: They raise LDL and can lower HDL cholesterol. Industrial trans fats worsen the blood-lipid profile by raising LDL cholesterol and often lowering protective HDL cholesterol. They are associated with increased cardiovascular risk, which is why many health authorities recommend eliminating partially hydrogenated oils. Trans fats still provide energy, are not vitamins and do not prevent inflammation; they may promote adverse inflammatory effects. The distractors are related to nutrition, but each describes a different nutrient, function, energy value or deficiency condition. A good solution identifies the key physiological clue and then checks every option against established nutritional science.

Correct answer: LDL cholesterol. Replacing unsaturated fats with substantial saturated fat intake tends to raise LDL cholesterol, an established cardiovascular risk factor. Dietary effects vary by food matrix and replacement nutrient, but replacing saturated fat with polyunsaturated fat generally improves lipid risk. Vitamin C, haemoglobin and calcium are not blood lipids and are not the direct target of saturated-fat intake.

Correct answer: Alpha-linolenic acid (ALA). Alpha-linolenic acid is an essential omega-3 fatty acid because humans cannot synthesize it and must obtain it from food. Palmitic acid is saturated, oleic acid is a non-essential monounsaturated fat and cholesterol is a sterol, not an essential omega-3.

Correct answer: Neural tube defects. Adequate folate before conception and in early pregnancy substantially reduces the risk of fetal neural tube defects such as spina bifida. Because the neural tube closes very early, supplementation is recommended before pregnancy is recognized in many cases. Night blindness is linked to vitamin A, scurvy to vitamin C and goitre to iodine deficiency. A good solution identifies the key physiological clue and then checks every option against established nutritional science.

Correct answer: Megaloblastic anaemia. Vitamin B12 deficiency impairs DNA synthesis and can produce megaloblastic macrocytic anaemia. It may also cause numbness, gait disturbance and other neurological damage, which distinguishes it from isolated folate deficiency. Iron deficiency is usually microcytic, malaria may cause haemolysis and blood loss has a separate mechanism. The distractors are related to nutrition, but each describes a different nutrient, function, energy value or deficiency condition.