ICAR AICE-JRF/SRF Human Nutrition & Nutritional Quality of Processed Foods: practice questions

1 · Energy: BMR, energy requirements and energy value of foods · hard

Why do reference values for energy give only an average requirement, with no figure set two standard deviations above it as for vitamins?

1. An intake above the average requirement would make most people gain weight over time
2. The variance of energy requirement is too small for a safety margin to make any difference
3. Energy needs cannot be measured in individuals, so their variance is unknown to committees
4. Energy is not a nutrient, so the Codex rules for nutrient reference values exclude it fully

2 · Proteins: essential amino acids, protein quality, BV, NPU, PER and PDCAAS/DIAAS · hard

A protein has an uncorrected amino acid score of 1.20 and a true faecal digestibility of 0.95. Its PDCAAS as used for regulatory purposes is:

1. 1.14
2. 1.00
3. 0.95
4. 1.20

3 · Proteins: essential amino acids, protein quality, BV, NPU, PER and PDCAAS/DIAAS · medium

The main reason FAO recommended DIAAS in place of PDCAAS is that DIAAS:

1. Uses rat growth over 28 days and so reflects the needs of a growing body more directly
2. Uses faecal nitrogen digestibility, which is easier to measure in human volunteers
3. Uses ileal digestibility of each amino acid, since colonic losses do not feed protein synthesis
4. Is truncated at 100 so all high-quality proteins can carry the same claim on the label

4 · Lipids: essential fatty acids, trans fats and health · medium

Ruminant trans fat in milk and meat consists mainly of:

1. Linoleic acid formed in body fat
2. Elaidic acid formed by partial hydrogenation
3. Erucic acid formed in the udder
4. Vaccenic acid formed by rumen bacteria

5 · Lipids: essential fatty acids, trans fats and health · hard

A manufacturer must replace a partially hydrogenated shortening in biscuits while keeping a plastic fat with similar melting behaviour. The most suitable technological route is:

1. Raise the deodorisation temperature of the oil to harden it before blending
2. Interesterify a blend of liquid oil with fully hydrogenated or palm hard stock
3. Use the unmodified liquid sunflower oil at the same level in the biscuit dough
4. Partially hydrogenate a different vegetable oil at a lower reaction temperature

6 · Water-soluble vitamins: functions, sources and deficiency · medium

A woman eats 200 µg of food folate and takes 100 µg of folic acid with meals. Her intake in dietary folate equivalents is:

1. 300 µg DFE
2. 260 µg DFE
3. 400 µg DFE
4. 370 µg DFE

7 · Bioavailability and the food matrix · hard

Two adults eat the same fortified meal; the iron-deficient one absorbs several times more iron than the iron-replete one. This shows the effect of:

1. A dietary factor, the chemical form of the fortificant iron
2. Bioaccessibility, which is higher in the deficient subject's meal
3. A host factor, iron status, acting through hepcidin on absorption
4. The food matrix, which differs between the two portions

8 · Bioavailability and the food matrix · medium

Iron absorption from a fortified food in humans is most precisely measured by:

1. Stable isotope labelling and erythrocyte incorporation
2. Total iron content of the food by atomic absorption
3. Faecal iron balance over a single day
4. PER of the food in growing rats

9 · Fortification, enrichment and biofortification · medium

Which iron compound is recommended for fortifying high-extraction (high-phytate) wheat flour because phytate inhibits it least?

1. Ferric pyrophosphate
2. Sodium iron EDTA
3. Reduced iron powder
4. Electrolytic iron

10 · Fortification, enrichment and biofortification · hard

A ministry plans mass fortification of a staple. Which food is the poorest choice of vehicle?

1. Edible oil refined centrally and used daily in most household cooking
2. Salt produced by a small number of refiners and eaten by everyone
3. A fresh vegetable from many small farms, eaten irregularly
4. Wheat flour milled by a few large mills and eaten daily by most adults