Section 1 The principles and key guidelines of nutrition

Question 1

Diet:

Answer 1

The current food intake and habits for any individual.

Question 2

Healthy eating:

Answer 2

Food intake that promotes correct and optimal operation of the structures and systems of the body.

Question 3

Balanced diet:

Answer 3

Eating foods of different types in amounts and levels that keep the body operating close to optimal level.

Question 4

Nutrient groups

Answer 4

Macronutrients:

• Carbohydrates.
• Proteins.
• Fats (lipids).

Micronutrients:

• Vitamins.
• Minerals.

Question 5

Peptide

Answer 5

Two or more amino acids joined together by peptide bonds.

Question 6

Proteins

Answer 6

Peptides No. of amino acids Prefix

Dipeptide 2 amino acids Di = 2

Tripeptide 3 amino acids Tri = 3

Oligopeptide 4-9 amino acids Oligo = few

Polypeptide 10+ amino acids Poly = many

Question 7

Amino acids

Answer 7

The building blocks of proteins.

Question 8

Amino acids

Answer 8

Essential Non-essential Conditional

Histidine Alanine Arginine

Isoleucine Asparagine Cysteine

Leucine Aspartic acid Glutamine

Lysine Glutamic acid Glycine

Methionine Proline

Phenylalanine Serine

Threonine Tyrosine

Tryptophan

Valine

Question 9

Catabolism and anabolism

Answer 9

Catabolism: processes by which substances are broken down into simpler molecules, releasing energy.

Anabolism: energy-requiring reaction in which simpler molecules are combined to form more complex substances.

Anabolism = to build up

Catabolism = to break down

Question 10

Protein requirements

Answer 10

Daily protein requirements (grams of protein per kilogram body mass)

Sedentary adult 0.8

Recreational adult exerciser 0.8-1.5

Adult endurance athlete 1.2-1.6

Growing teenage athlete 1.5-2.0

Adult building muscle mass 1.5-1.7

Estimated upper adult limit 2.0

Question 11

Carbohydrates

Answer 11

All carbohydrates are made up of molecules or units called saccharides.

There are three basic categories:

• Simple carbohydrates – ‘sugar’.
• Complex carbohydrates – ‘starches’.
• Non-starch polysaccharides (NSP) – ‘fibre’.

Question 12

Dietary carbohydrate

Answer 12

• Ultimately sent to the liver, muscles or used immediately as a fuel.
• Glucose may enter the adipose tissue (fat tissue) to help store fat.
• Carbohydrates and fats contribute significantly to energy requirements.

Question 13

Simple carbohydrates

Answer 13

Fruit (healthy choice)

• Contains fructose and glucose in varying amounts
• Contains vitamins and minerals
• Contains antioxidants and phytochemicals
• Contains high levels of dietary fibre
• Contains traces of amino acids
• Cheap and convenient

Biscuits, cake, confectionary, soft drinks (less healthy)

• Contain excessive sugar - higher than 15g per 100g
• Contain processed, low quality fats
• High energy density
• Contain no vitamins or minerals
• Adversely affect insulin response

Question 14

Complex carbohydrates

Answer 14

Refined carbohydrate

• White bread
• White pasta and rice
• Cakes, biscuits, pastries
• Rice cakes

Properties

• Contain excessive sugar; over 15g per 100g
• Contain processed, low quality fats
• High energy density
• No vitamins and minerals
• Adversely affects insulin response

Unrefined carbohydrate

• Wholemeal or whole grain products
• Quinoa
• Frozen/fresh vegetables
• Pulses

Properties

• Contain fructose and glucose in varying amounts
• Contain antioxidants and phytochemicals
• High levels of dietary fibre
• Contain vitamins and minerals
• Contain trace of amino acids

Question 15

Fibre

Answer 15

Insoluble fibre:

• Found in the outer protective layer of plants.
• Unrefined wheat, bran, rye, rice and most other grains.

Soluble fibre:

• Found in the inner part of plants.
• Barley, broccoli, prunes, apples, citrus fruits and oats.

Question 16

Fats (lipids)

Answer 16

Oils: lipids that are liquid at room temperature.

Fats: lipids that are solid at room temperature.

Question 17

Classification and function of fats

Answer 17

Key physiological functions of lipids:

• Formation of virtually all cell membranes.
• Formation of myelin sheath within nervous system.
• Constitutes majority of CNS and spinal cord.
• Synthesis of steroid hormones.
• Assists in the regulation of enzymes.
• Insulation through subcutaneous adipose tissue.
• Protection of internal organs.
• Transportation, storage and utilisation of fat soluble vitamins A, D, E, K.
• Fuel source during lower intensity workloads.
• Storage of energy within the adipose tissue.

Question 18

Lipids

Answer 18

A group of organic molecules, most of which do not dissolve in water.

Question 19

Fatty acids

Answer 19

• Monounsaturated.
• Polyunsaturated.
• Saturated.

Question 20

Fatty acid:

Answer 20

an organic molecule made up of a chain of carbons linked to hydrogens with an acid group at one end.

Despite long-standing assertions to the contrary, the brain can use fatty acids as a source of fuel.

Question 21

Triglycerides

Answer 21

The major form of lipid in food and in the body is known as a triglyceride.

It consists of three fatty acids attached to a glycerol molecule.

Question 22

Saturated fat

Answer 22

Animal sources: meat (beef, pork, lamb, venison), poultry (chicken, duck), dairy (milk, cheese yoghurt, cream, butter), eggs.

Non-animal sources: palm oil, coconut oil.

Question 23

Unsaturated oil

Answer 23

Monounsaturated: a single double bond – single bend in molecule.

Polyunsaturated: several double bonds – several bends in molecule.

Question 24

Monounsaturated fatty acids

Answer 24

Sources of monounsaturated fatty acids:

• Olives/olive oil.
• Lard.
• Beef dripping.
• Peanut oil.
• Rapeseed oil.
• Avocado.
• Nuts.
• Seeds.

Question 25

Polyunsaturated fatty acids

Answer 25

Omega-3 fatty acids: oily fish, flax oil, walnuts, pasture-reared eggs. Omega-6 fatty acids: sunflower seeds, sunflower oil, safflower oil, pumpkin seeds, sesame seeds. Note: all oils need to be cold pressed and remain unprocessed.

Question 26

Hydrogenated fats

Answer 26

Hydrogenated fats (saturated fats) are unnatural fats that are detrimental to your health. * Margarine. * Vegetable shortening. * Packaged snacks. * Baked foods, especially premade versions. * Ready-to-use dough. * Fried foods. * Coffee creamers, both dairy and non-dairy.

Question 27

Cholesterol

Answer 27

Dietary cholesterol intake low – body increases the synthesis of its own supply. Dietary cholesterol intake increases – cholesterol production falls. Lipoproteins completely encase lipids for transport in the blood.

Question 28

Functions of cholesterol

Answer 28

Very low density lipoproteins (VLDL): synthesised by the liver, contain cholesterol and triglycerides, transport triglycerides into adipose tissue. Low density lipoproteins (LDL): formed from VLDLs once they have unloaded most of their triglycerides, transport the remaining cholesterol to cells throughout the body that are in need. High density lipoproteins (HDL): synthesised by the liver, transport excess cholesterol from the tissues and blood back to the liver.

Question 29

Micronutrients – vitamins

Answer 29

Fat-soluble vitamins: * A * D * E * K Water-soluble vitamins: * B * C

Question 30

Micronutrients – minerals

Answer 30

* Build strong bones and teeth. * Control body fluids inside and outside cells. * Turn food into energy.

Question 31

Antioxidants

Answer 31

Sources of antioxidant nutrients: * Vitamin C – citrus fruits, green vegetables, peppers, tomatoes, potatoes. * Vitamin E – unrefined vegetable oils, egg yolks, whole grains, almonds, nuts, green leafy vegetables. * Zinc – oysters, ginger root, lamb, nuts , grains, eggs, peas. * Selenium – grains, meat, fish, brazil nuts, shellfish, dairy.

Question 32

US national food and nutritional guidelines

Answer 32

Question 33

UK national food guidelines

Answer 33

Healthy eating tips: 1. Base your meals on starchy foods. 2. Eat lots of fruit and vegetables (5 portions per day). 3. Eat more fish (2 portions a week, 1 oily). 4. Cut down on saturated fat and sugar. 5. Try to eat less salt, no more than 6g a day. 6. Get active and try to be a healthy weight. 7. Drink plenty of water (6-8 glasses per day). 8. Don’t skip breakfast. National food model targets: * Adult males: 2550 calories per day. * Adult females: 1950 calories per day.

Question 34

Traffic light system

Answer 34

* Red = high. * Amber = medium. * Green = low.

Question 35

Food Standards Agency (FSA)

Answer 35

Food production, labelling, and manufacture are governed by the 1990 Food Safety Act.

Question 36

Food marketing terminology

Answer 36

* Fresh: ‘to differentiate food sold a short time after harvest.’ * Pure: ‘single ingredient foods...or to highlight the quality of ingredients of a food.’ * Natural: ‘comprised of natural ingredients, not the work of man.’ * Authentic: ‘remains unchanged...originates from the area implied by its name.’ * Homemade: ‘made in the home, or of domestic manufacture.’ * Traditional: ‘a method of preparation that has existed for a significant period.’ * Farmhouse: ‘other than bread, it should refer to food produced on a farm.’ * Original: ‘a method of preparation that has remained essentially unchanged over time.’

Question 37

Healthy marketing terminology

Answer 37

* ‘Light, low, reduced or high’: there are no specific guidelines for these terms, but they should not mislead. * ‘Reduced or low fat’: this must be at least 25% lower in fat, but often calories are maintained by adding other ingredients. * ‘Low calorie’: this must have lower calories than the original, but there is no set level. * ‘Sugar free’: sugar has not been added, but almost always an artificial sweetener has been used for taste.

Question 38

Refined sugars and sweeteners

Answer 38

Commonly added sugars and caloric sweeteners: * Dextrose. * Glucose syrup. * Inverted sugar syrup. * High fructose corn starch. * Mannitol. * Xylitol. * Sorbitol. * Maltodextrin. Artificial sweeteners: * Aspartame. * Sucralose. * Acesulfame. * Saccharin.