I85PREP
⌘ K
QCAA Food & Nutrition study materials
QCAA Food & Nutrition study resources

QCAA Food & Nutrition practice questions

One question at a time. Build your QCAA Food & Nutrition understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which macronutrient is the body's most concentrated source of energy, supplying about 37 kJ per gram?

  1. Protein
  2. Dietary fibre
  3. Carbohydrate
  4. Dietary fat Correct answer.

Explanation

Fat yields roughly 37 kilojoules per gram, which is more than double the energy density of carbohydrate or protein at about 17 kilojoules per gram. Fibre contributes very little available energy because humans lack enzymes to digest it. This is why reducing fat is an effective way to lower the energy density of a diet.

Question 2Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which enzyme begins the chemical digestion of starch in the mouth?

  1. Trypsin
  2. Pepsin
  3. Salivary amylase Correct answer.
  4. Lipase

Explanation

Salivary amylase, also called ptyalin, hydrolyses starch into shorter chains such as maltose while food is chewed. Pepsin and trypsin act on proteins in the stomach and small intestine respectively, and lipase acts on fats. Amylase activity stops once swallowed food becomes acidic in the stomach.

Question 3Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which vitamin is fat-soluble and therefore absorbed with dietary lipids?

  1. Vitamin B12
  2. Vitamin B1
  3. Vitamin C
  4. Vitamin A Correct answer.

Explanation

Vitamin A is fat-soluble and is packaged into micelles with dietary fats before absorption in the small intestine. Vitamin C and the B-group vitamins are water-soluble and travel more directly into the portal blood. Fat malabsorption therefore risks deficiency of vitamin A and other fat-soluble vitamins.

Question 4Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

What is the primary role of vitamin C in the body?

  1. Regulating calcium absorption from the gut
  2. Forming the core of the haemoglobin molecule
  3. Acting as a cofactor in blood clotting reactions
  4. Acting as an antioxidant and cofactor in collagen synthesis Correct answer.

Explanation

Vitamin C is a water-soluble antioxidant and a required cofactor for the enzymes that hydroxylate proline and lysine during collagen formation. Collagen is essential for skin, blood vessels and wound healing, which explains the bleeding gums seen in scurvy. It also enhances absorption of non-haem iron.

Question 5Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which mineral is a key structural component of bones and teeth and is regulated by calcitriol?

  1. Copper
  2. Calcium Correct answer.
  3. Sodium
  4. Iodine

Explanation

Calcium is deposited as hydroxyapatite in bone and tooth enamel, providing rigidity. The active form of vitamin D, calcitriol, increases intestinal calcium absorption and helps maintain plasma calcium. When intake is low, bone resorption releases calcium to protect blood levels.

Question 6Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which condition is caused by a deficiency of iodine in the diet?

  1. Scurvy
  2. Rickets
  3. Pellagra
  4. Goitre Correct answer.

Explanation

Iodine is required to synthesise thyroid hormones, and a shortfall causes the thyroid gland to enlarge as it attempts to trap more iodine, producing goitre. Severe deficiency during pregnancy can impair fetal brain development. Iodised salt is a common public health strategy to prevent it.

Question 7Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which statement best describes the difference between a food allergy and a food intolerance?

  1. An allergy involves immune antibodies while an intolerance does not Correct answer.
  2. An allergy is caused by a deficiency of digestive enzymes
  3. An intolerance is always more severe than an allergy
  4. An intolerance involves immunoglobulin E antibodies

Explanation

A food allergy is an immune-mediated response, often involving immunoglobulin E antibodies that trigger histamine release, so symptoms can appear rapidly and affect many body systems. A food intolerance does not involve this immune mechanism and usually relates to digestion or metabolism. This distinction affects diagnosis and the management advice given to clients.

Question 8Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which process describes the breakdown of triglycerides into fatty acids and glycerol?

  1. Denaturation
  2. Hydrolysis Correct answer.
  3. Oxidation
  4. Condensation

Explanation

Hydrolysis uses water to cleave the ester bonds joining fatty acids to the glycerol backbone, releasing free fatty acids and glycerol. Condensation is the reverse reaction that forms those bonds. Oxidation involves the loss of electrons and is a separate metabolic event.

Question 9Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A student eats a slice of white bread. Which enzyme, delivered from the pancreas, completes the digestion of the resulting starch fragments into glucose?

  1. Pancreatic amylase Correct answer.
  2. Pepsin
  3. Pancreatic lipase
  4. Lactase

Explanation

Pancreatic amylase is secreted into the duodenum and continues the hydrolysis of starch into maltose and other short chains. Maltase and other brush-border enzymes then finish the job by releasing glucose for absorption. Without pancreatic amylase, starch digestion would be substantially impaired.

Question 10Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A person follows a vegan diet and has low iron stores. Which dietary strategy best improves non-haem iron absorption at meals?

  1. Drinking strong tea with each meal
  2. Pairing legumes with a vitamin C rich food Correct answer.
  3. Taking calcium supplements with meals
  4. Increasing dietary fibre at every meal

Explanation

Non-haem iron from plant foods is poorly absorbed, but vitamin C reduces ferric iron to the more soluble ferrous form and forms an absorbable complex. Combining legumes or leafy greens with capsicum, citrus or tomato therefore raises absorption. This is a practical strategy for people relying on plant iron sources.

Question 11Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Amylose and amylopectin differ in their structure. Which statement correctly compares them?

  1. Amylose is highly branched while amylopectin is linear
  2. Amylose is linear while amylopectin is branched Correct answer.
  3. Amylopectin is a protein and amylose is a carbohydrate
  4. Both are branched to the same degree

Explanation

Amylose consists mainly of unbranched alpha-1,4 linked glucose chains, whereas amylopectin has additional alpha-1,6 branch points that create a highly branched molecule. The branching of amylopectin gives more ends for enzymes to attack, so it digests more rapidly. Both, however, are polysaccharides made of glucose.

Question 12Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which change to a meal is most likely to lower its glycaemic index without reducing its energy content?

  1. Replacing white bread with wholemeal bread Correct answer.
  2. Serving the meal with a sugary drink
  3. Adding sugar to the meal
  4. Blending the meal into a fine puree

Explanation

Wholemeal bread retains bran and germ, so its starch is digested more slowly and the glucose response rises less sharply than after white bread. Adding sugar, blending or consuming sugary drinks tends to raise the glycaemic response. The glycaemic index therefore reflects carbohydrate quality rather than energy density.

Question 13Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which statement correctly describes the role of bile in fat digestion?

  1. Bile enzymes hydrolyse triglycerides in the stomach
  2. Bile neutralises fatty acids to stop lipase activity
  3. Bile transports fatty acids directly into the bloodstream
  4. Bile emulsifies fat into small droplets, increasing the surface area for lipase Correct answer.

Explanation

Bile salts are not enzymes; they act as emulsifiers that break large fat globules into many small droplets. This greatly increases the surface area available to pancreatic lipase, speeding hydrolysis. Bile also helps neutralise acidic chyme so intestinal enzymes can work effectively.

Question 14Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

During prolonged fasting, which process provides glucose for the brain?

  1. Direct absorption of glucose from the colon
  2. Glycogenolysis continuing indefinitely
  3. Gluconeogenesis from amino acids and glycerol Correct answer.
  4. Beta-oxidation of fatty acids into glucose

Explanation

Liver glycogen is depleted within roughly a day, so the body relies increasingly on gluconeogenesis, mainly in the liver and to a lesser extent the kidney. Amino acids from muscle protein and glycerol from fat breakdown are key substrates. Fatty acids themselves cannot be converted to glucose in humans.

Question 15Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which of the following is the main function of dietary protein in the body?

  1. Dissolving fat-soluble vitamins in the gut
  2. Supplying the primary fuel for resting muscle
  3. Providing nitrogen and amino acids for tissue growth and repair Correct answer.
  4. Acting as the main store of energy in adipose tissue

Explanation

Dietary protein supplies essential amino acids and nitrogen needed to synthesise body proteins such as enzymes, hormones and structural tissue. Protein is used for energy mainly when intake exceeds needs or when energy is scarce. Fat, not protein, is the body's main energy store.

Question 16Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A food label lists 20 g of carbohydrate per serve, of which 8 g is sugar. Which conclusion is best supported?

  1. Most of the carbohydrate is not sugar Correct answer.
  2. The product is sugar-free
  3. The product contains no starch
  4. The product provides no energy

Explanation

The sugar figure is a subset of the total carbohydrate, so 12 g of the 20 g is non-sugar carbohydrate such as starch or fibre. Reading the two figures together gives a more accurate picture than the total alone. It does not mean the product is sugar-free or starch-free.

Question 17Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which combination of dietary changes is most consistent with reducing the risk of cardiovascular disease?

  1. Replacing saturated fat with polyunsaturated fat and increasing soluble fibre Correct answer.
  2. Increasing salt and reducing potassium-rich foods
  3. Increasing trans fat and reducing plant foods
  4. Increasing saturated fat and reducing fibre

Explanation

Replacing saturated fat with polyunsaturated fat lowers LDL cholesterol, and soluble fibre such as beta-glucan binds bile acids and further reduces cholesterol. Together these changes address major modifiable risk factors. Increasing saturated fat, trans fat or salt would increase risk instead.

Question 18Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which statement about dietary fibre and bowel health is correct?

  1. Soluble fibre is fermented by colonic bacteria to short-chain fatty acids Correct answer.
  2. Insoluble fibre ferments completely in the stomach
  3. All fibre is absorbed unchanged in the small intestine
  4. Fibre increases the glycaemic index of foods

Explanation

Soluble fibres such as pectin and beta-glucan are fermented by colonic bacteria, producing short-chain fatty acids that nourish colon cells. Insoluble fibre mainly adds bulk and speeds transit. Neither type is absorbed unchanged in the small intestine.

Question 19Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which vitamin functions as a coenzyme in energy-yielding metabolism and is found in wholegrains and legumes?

  1. Vitamin E
  2. Vitamin K
  3. Vitamin D
  4. Vitamin B3 (niacin) Correct answer.

Explanation

Niacin forms part of the coenzymes NAD and NADP, which carry electrons in the reactions that release energy from carbohydrate, fat and protein. Wholegrains and legumes are useful sources, and tryptophan can be converted to niacin in the body. Deficiency causes pellagra.

Question 20Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A client reports bloating and diarrhoea after drinking milk but can eat yoghurt without symptoms. Which explanation is most plausible?

  1. They have a milk protein allergy affecting all dairy foods
  2. They are deficient in pancreatic amylase
  3. They have coeliac disease triggered by milk
  4. They have reduced lactase activity, and yoghurt provides some lactase and is partly fermented Correct answer.

Explanation

Lactose intolerance arises when lactase activity in the small intestine is insufficient to split lactose, so it reaches the colon and is fermented, causing gas and diarrhoea. Yoghurt is lower in lactose and supplies bacterial lactase, so it is often better tolerated. This pattern is typical of lactose intolerance rather than allergy.

Question 21Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which amino acid is classified as limiting in a diet based mainly on wheat, and how is this best addressed?

  1. Methionine, addressed by eating more wheat
  2. Leucine, addressed by adding sugar
  3. Lysine, addressed by combining wheat with legumes Correct answer.
  4. Alanine, addressed by adding oil

Explanation

Cereal proteins such as wheat are typically low in lysine, whereas legumes are rich in lysine but low in methionine. Combining cereals with legumes provides a more complete essential amino acid profile, a practice called protein complementation. This improves the overall quality of a plant-based diet.

Question 22Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which statement best explains why a diet high in refined carbohydrate may contribute to dental caries?

  1. Saliva stops producing minerals when carbohydrate is eaten
  2. Oral bacteria ferment sugars into acids that demineralise enamel Correct answer.
  3. Refined carbohydrate directly dissolves tooth enamel without bacteria
  4. Refined carbohydrate raises salivary pH above neutral

Explanation

Cariogenic bacteria such as Streptococcus mutans ferment sugars to lactic acid, which lowers plaque pH below the critical level and demineralises enamel. Frequent consumption of refined carbohydrate keeps pH low and prolongs demineralisation. Saliva normally buffers and remineralises, but repeated acid attacks overwhelm this protection.

Question 23Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A person with coeliac disease must avoid a particular protein fraction. Which food group is the primary source that must be excluded?

  1. All nuts and seeds
  2. All fresh fruits and vegetables
  3. All dairy products
  4. Gluten-containing cereals such as wheat, barley and rye Correct answer.

Explanation

Coeliac disease is an autoimmune reaction to gluten proteins, particularly the gliadin fraction of wheat, and related prolamins in barley and rye. Strict avoidance of these cereals and their derivatives is the only effective treatment. Fruits, vegetables, dairy and nuts are naturally gluten-free unless contaminated.

Question 24Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which metabolic explanation best accounts for weight regain after a period of substantial weight loss?

  1. Protein oxidation stops completely after weight loss
  2. Basal metabolic rate rises sharply as body mass falls
  3. Fat cells are permanently destroyed and cannot store lipid again
  4. Resting energy expenditure falls and appetite hormones favour increased intake Correct answer.

Explanation

Loss of lean and fat mass lowers resting energy expenditure, while changes in hormones such as leptin and ghrelin increase hunger and reduce satiety. The combination creates an energy gap that favours regain when old habits resume. This adaptive response is a physiological, not merely psychological, phenomenon.

Question 25Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A dietary analysis shows high intake of phytate and low intake of calcium and vitamin D. Which outcome is most likely?

  1. Improved zinc and iron absorption
  2. Reduced mineral absorption contributing to poor bone mineralisation Correct answer.
  3. Increased iron absorption with no effect on bone
  4. Enhanced calcium absorption due to phytate binding

Explanation

Phytate binds minerals such as calcium, iron and zinc in the gut and reduces their absorption, while low calcium and vitamin D intakes further limit mineralisation of bone. Together these factors increase the risk of poor bone density and, in children, rickets. The effect is additive rather than protective.

Question 26Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which nutrient is the body's most concentrated source of energy per gram?

  1. Fat Correct answer.
  2. Carbohydrate
  3. Protein
  4. Alcohol

Explanation

Fat provides about 37 kilojoules per gram, which is more than twice the energy released by the same mass of protein or carbohydrate, each at roughly 17 kilojoules per gram. Alcohol supplies about 29 kilojoules per gram, so it is also less concentrated than fat. This density reflects the highly reduced, carbon-rich structure of fatty acids.

Question 27Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which organ produces the majority of digestive enzymes acting in the small intestine?

  1. The stomach
  2. The pancreas Correct answer.
  3. The salivary glands
  4. The liver

Explanation

The pancreas secretes pancreatic amylase, lipase and proteases into the duodenum, where they complete the breakdown of the major macronutrients. The liver produces bile rather than digestive enzymes, and the stomach secretes acid and pepsin only. Salivary enzymes act mainly in the mouth and are inactivated in the stomach.

Question 28Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which mineral is a structural component of haemoglobin?

  1. Iron Correct answer.
  2. Calcium
  3. Zinc
  4. Iodine

Explanation

Iron sits at the centre of the haem group in haemoglobin, allowing each molecule to bind oxygen for transport from the lungs to tissues. Calcium is mainly a structural mineral in bone, zinc supports enzyme function and immunity, and iodine is used to make thyroid hormones.

Question 29Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which vitamin is synthesised in the skin when it is exposed to ultraviolet light?

  1. Vitamin B12
  2. Vitamin K
  3. Vitamin C
  4. Vitamin D Correct answer.

Explanation

Ultraviolet B radiation converts a cholesterol derivative in the skin into a precursor that is later activated in the liver and kidneys to form calcitriol. Vitamin C and the B group vitamins must be supplied by the diet because humans cannot synthesise them in useful amounts. Vitamin K is produced partly by gut bacteria rather than by sunlight.

Question 30Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which statement describes the main role of hydrochloric acid in the stomach?

  1. It absorbs glucose across the stomach wall
  2. It hydrolyses starch into maltose
  3. It emulsifies dietary fats into small droplets
  4. It activates pepsinogen and kills most ingested bacteria Correct answer.

Explanation

Hydrochloric acid creates the strongly acidic environment that converts inactive pepsinogen into active pepsin and destroys many microorganisms swallowed with food. Fat emulsification is performed by bile salts in the small intestine, and starch digestion is carried out by amylase. The stomach absorbs very little glucose.

Question 31Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which food is a rich source of omega-3 fatty acids?

  1. White rice
  2. Potato
  3. Butter
  4. Salmon Correct answer.

Explanation

Oily fish such as salmon contain substantial amounts of the long-chain omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. Rice and potato are predominantly carbohydrate foods with negligible fat, and butter is dominated by saturated and monounsaturated fat.

Question 32Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which nutrient deficiency causes scurvy?

  1. Iron
  2. Vitamin C Correct answer.
  3. Folate
  4. Thiamin

Explanation

Vitamin C is required for the hydroxylation of proline and lysine in collagen, so a deficiency weakens connective tissue and produces bleeding gums, poor wound healing and bruising. Thiamin deficiency causes beriberi, folate deficiency causes megaloblastic anaemia, and iron deficiency causes microcytic anaemia.

Question 33Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which process converts glucose into pyruvate in the cytoplasm of a cell?

  1. Beta-oxidation
  2. Gluconeogenesis
  3. Glycolysis Correct answer.
  4. The citric acid cycle

Explanation

Glycolysis is a sequence of cytoplasmic reactions that splits one glucose molecule into two pyruvate molecules and yields a small net amount of ATP. The citric acid cycle occurs in the mitochondria, beta-oxidation breaks down fatty acids, and gluconeogenesis builds glucose rather than breaking it down.

Question 34Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A teenager eats a breakfast cereal fortified with calcium and drinks a glass of milk with it. Which factor in this meal most enhances calcium absorption?

  1. The oxalate in the milk
  2. The lactose provided by the milk Correct answer.
  3. The dietary fibre in the cereal
  4. The phytate naturally present in the cereal

Explanation

Lactose and the acidic environment it helps create in the small intestine improve the solubility and uptake of calcium. Phytate and oxalate both bind calcium and reduce its absorption, and fibre can also limit mineral availability. Milk is not a significant source of oxalate.

Question 35Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A person wants to increase their intake of resistant starch. Which change is most effective?

  1. Eating green bananas and cooled cooked legumes Correct answer.
  2. Choosing white bread instead of wholegrain bread
  3. Cooking potatoes and eating them hot
  4. Drinking freshly squeezed orange juice

Explanation

Resistant starch escapes digestion in the small intestine and ferments in the colon, and its content is high in unripe bananas and in cooked legumes that have been cooled, which promotes retrogradation. Hot freshly cooked potato contains mostly gelatinised, digestible starch, and fruit juice contains almost no starch.

Question 36Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Two snacks provide the same total energy. Snack A contains 15 g protein, 5 g fat and 40 g carbohydrate; Snack B contains 5 g protein, 15 g fat and 40 g carbohydrate. Which statement is correct?

  1. Snack A provides more total energy than Snack B
  2. Both snacks provide identical energy and satiety
  3. Snack A provides more energy from fat than Snack B
  4. Snack B provides more total energy than Snack A Correct answer.

Explanation

Using the energy factors of 17 kilojoules per gram for protein and carbohydrate and 37 kilojoules per gram for fat, Snack A supplies about 1020 kilojoules while Snack B supplies about 1220 kilojoules. The extra 10 g of fat in Snack B adds more energy than the 10 g of protein it replaces. Satiety cannot be assumed to be identical from these figures alone.

Question 37Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which explanation best accounts for the higher protein quality of egg compared with wheat?

  1. Egg contains more non-essential amino acids
  2. Egg protein is absorbed more slowly
  3. Egg contains more total nitrogen than wheat
  4. Egg provides a better balance of essential amino acids Correct answer.

Explanation

Protein quality depends on the pattern of essential amino acids relative to human requirements and on digestibility. Egg protein closely matches human needs and is highly digestible, whereas wheat is low in lysine, which limits its use for protein synthesis. Total nitrogen content alone does not determine quality.

Question 38Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A student wants to reduce the glycaemic load of a meal containing 60 g of available carbohydrate from white rice. Which change reduces glycaemic load most directly?

  1. Replacing half the rice with lentils of equal carbohydrate content Correct answer.
  2. Adding a source of saturated fat to the rice
  3. Drinking water before the meal
  4. Eating the meal more quickly

Explanation

Glycaemic load is the product of a food's glycaemic index and its available carbohydrate content divided by 100. Substituting lentils, which have a much lower glycaemic index, lowers the overall value even when carbohydrate grams are matched. Adding fat, drinking water or changing eating speed does not reliably reduce the carbohydrate-driven load.

Question 39Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which mechanism best explains why a high-salt diet raises blood pressure in salt-sensitive people?

  1. Sodium directly destroys red blood cells
  2. Sodium binds to dietary calcium in the gut
  3. Sodium blocks the action of insulin
  4. Sodium increases water retention and plasma volume Correct answer.

Explanation

Excess sodium draws water into the extracellular fluid, expanding plasma volume and increasing the pressure exerted on vessel walls. In susceptible individuals this also interacts with vascular and hormonal regulation. Sodium does not destroy erythrocytes, block insulin action or act primarily by binding calcium.

Question 40Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which statement best describes the fate of excess dietary carbohydrate that is not immediately needed for energy?

  1. It is stored as glycogen or converted to fat Correct answer.
  2. It is converted directly to protein in muscle
  3. It is excreted unchanged in urine
  4. It is converted to urea in the liver

Explanation

Glucose beyond immediate energy needs is first stored as glycogen in liver and muscle, and once those stores are full the surplus is converted to fatty acids and stored as adipose tissue. The body does not excrete unused glucose unchanged, and carbohydrate cannot be converted directly into protein without first supplying carbon skeletons and nitrogen from other sources.

Question 41Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A lacto-ovo vegetarian wants to improve zinc intake. Which food choice is most useful?

  1. Refined white flour products
  2. Legumes and wholegrains prepared by soaking and sprouting Correct answer.
  3. White sugar
  4. Fresh lettuce and cucumber

Explanation

Legumes and wholegrains are good plant sources of zinc, and soaking, sprouting and leavening reduce phytate, which otherwise binds zinc and limits absorption. Refined flour has lost much of its mineral content, and lettuce, cucumber and sugar contribute negligible zinc.

Question 42Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which change to a person's diet would most reduce their intake of saturated fat without lowering protein intake?

  1. Replacing grilled chicken with fried chicken
  2. Replacing butter with olive oil spread Correct answer.
  3. Replacing lentils with white rice
  4. Replacing nuts with potato chips

Explanation

Butter is high in saturated fat, whereas olive oil spread is predominantly unsaturated, so the swap lowers saturated fat while protein intake is essentially unchanged. Frying chicken in oil adds fat, replacing lentils with rice lowers protein, and replacing nuts with chips increases saturated fat.

Question 43Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which statement correctly describes the difference between a fat-soluble and a water-soluble vitamin in terms of absorption?

  1. Fat-soluble vitamins are absorbed with dietary lipids via micelles Correct answer.
  2. Fat-soluble vitamins are absorbed directly into the portal vein
  3. Water-soluble vitamins are stored extensively in adipose tissue
  4. Water-soluble vitamins require bile salts for absorption

Explanation

Fat-soluble vitamins A, D, E and K are packaged with dietary lipids into micelles and absorbed with them via the lymphatic route, which is why fat malabsorption impairs their status. Water-soluble vitamins are generally absorbed directly into the portal blood and are not stored in large amounts in adipose tissue.

Question 44Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which hormone lowers blood glucose by promoting glucose uptake into muscle and adipose tissue?

  1. Insulin Correct answer.
  2. Glucagon
  3. Adrenaline
  4. Cortisol

Explanation

Insulin is released by pancreatic beta cells in response to rising blood glucose and stimulates translocation of glucose transporters to cell membranes. Glucagon, cortisol and adrenaline all act in the opposite direction by raising blood glucose during fasting or stress.

Question 45Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A person with chronic kidney disease is advised to moderate protein intake. Which rationale best explains this advice?

  1. Protein directly raises blood cholesterol in kidney disease
  2. Protein inhibits the absorption of dietary calcium
  3. Protein is completely indigestible in kidney disease
  4. Nitrogenous waste from protein metabolism accumulates when filtration is impaired Correct answer.

Explanation

Protein metabolism produces urea and other nitrogenous wastes that healthy kidneys excrete. When filtration is impaired these wastes accumulate, so moderating protein reduces the load on the kidney and the buildup of uraemic toxins. Protein is digestible in kidney disease, and its relationship with cholesterol and calcium is not the reason for this advice.

Question 46Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A dietary analysis of a young woman shows low ferritin, low haemoglobin and a diet high in tea consumed with meals. Which explanation best links the dietary pattern to her iron status?

  1. Tea tannins enhance non-haem iron absorption
  2. Tea provides a rich source of haem iron
  3. Tea increases vitamin C absorption, which reduces iron stores
  4. Tea polyphenols inhibit non-haem iron absorption when consumed with meals Correct answer.

Explanation

Polyphenols and tannins in tea form complexes with non-haem iron in the gut and reduce its absorption, so drinking tea with meals can worsen iron status when requirements are high. Tea does not supply haem iron, and vitamin C enhances rather than reduces iron absorption.

Question 47Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which metabolic adaptation best explains the loss of lean mass often seen during very rapid weight loss?

  1. Mobilisation of amino acids from muscle for gluconeogenesis Correct answer.
  2. Increased muscle protein synthesis due to a large energy deficit
  3. Enhanced storage of glycogen in adipose tissue
  4. Reduced basal metabolic rate caused by increased thyroid hormone

Explanation

When energy intake falls sharply and glycogen reserves are depleted, the body uses amino acids from skeletal muscle as substrates for gluconeogenesis to maintain blood glucose. This contributes to a decline in lean tissue, and the accompanying reduction in thyroid hormone lowers resting energy expenditure. A large deficit does not increase muscle protein synthesis.

Question 48Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A food has a high glycaemic index but a low glycaemic load per serve. Which explanation is most consistent with this finding?

  1. The food has a very high fat content that raises its index
  2. The serve contains a small amount of available carbohydrate Correct answer.
  3. The food contains no carbohydrate at all
  4. The food is composed mainly of resistant starch

Explanation

Glycaemic load multiplies the glycaemic index by the grams of available carbohydrate in a serve and divides by 100, so a small carbohydrate portion can produce a low load despite a high index. A food with no carbohydrate would have an undefined or zero index, and a high fat content usually lowers the index. Resistant starch is not counted as available carbohydrate and would lower the index itself.

Question 49Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

Which biochemical role best explains why vitamin B12 deficiency causes megaloblastic anaemia?

  1. It directly transports oxygen in the bloodstream
  2. It is required for haem synthesis in the bone marrow
  3. It is needed to convert folate to its active form for DNA synthesis Correct answer.
  4. It stimulates the release of erythropoietin from the kidney

Explanation

Vitamin B12 is a cofactor for methionine synthase, which regenerates the active tetrahydrofolate needed for thymidylate and DNA synthesis. Without it, red cell precursors divide abnormally and enlarge, producing megaloblastic anaemia. Haem synthesis depends on iron and B6, while oxygen transport and erythropoietin release are separate processes.

Question 50Food science and nutrition (nutrients, food chemistry, digestion, metabolism, diet-related health)

A patient with chronic pancreatitis develops steatorrhoea and low blood levels of vitamins A and E. Which explanation is most consistent?

  1. Reduced pancreatic lipase limits fat digestion and fat-soluble vitamin absorption Correct answer.
  2. Increased gastric acid destroys water-soluble vitamins
  3. Increased intestinal motility prevents protein digestion
  4. Reduced bile production prevents carbohydrate absorption

Explanation

Chronic pancreatitis reduces the secretion of pancreatic lipase and other enzymes, so triglycerides are incompletely digested and fat is lost in the stool as steatorrhoea. Because vitamins A and E require efficient fat digestion and micelle formation for absorption, their blood levels fall as well. Bile production and gastric acid are not the primary defect here.