macronutrients

Question 1

nutrients

Answer 1

chemical substances found in foods are essential to life and maintaining good health (varies with age, gender, activity, size)

Question 2

macronutrients

Answer 2

required in large amounts for healthy growth and to provide energy for the body’s daily needs

Question 3

basal metabolic rate (bmr)

Answer 3

energy needed to perform the involuntary energy needs of a person’s body; highest in young people, decreases with age

Question 4

protein: complete and incomplete

Answer 4

• protein => build and repair body cells / important during periods of growth => meat, fish, nuts, eggs, milk, cheese
• amino acids; made of carbon, hydrogen, oxygen, nitrogen
• body requires 20 amino acids, 8 of which are essential (from foods rich in protein), 12 are non-essential
• functions: growth and repair of cells, repair of hard cells (bones/teeth) and soft cells (muscle), manufacture enzymes + hormones + haemoglobin, energy source if insufficient carbohydrate is eaten
  ==> complete protein: provide 8 essential since body cannot manufacture them; animal origin e.g. meat, poultry, fish, milk, cheese, yoghurt
  ==> incomplete protein: lacks at least one of essential amino acids; vegetable origin e.g. nuts, pulses, seeds, wholegrain cereals, vegetables

Question 5

carbohydrates: starches, sugars, and fibre or cellulose

Answer 5

• provide energy
• bread, cereals, rice, pasta
• compounds of hydrogen, carbon, oxygen
• functions: important source of energy and fibre
• high in carbs: bread, rice, pasta, potatoes
• broken down into simple sugars during digestion
• glycaemic index (GI) => rate at which foods release glucose into bloodstream (high GI = quick release, low = slow release; delays hunger)
  ==> simple sugars => monosaccharides (e.g. glucose, fructose, galactose), disaccharides (e.g. sucrose, lactose, maltose)
  ==> complex sugars => polysaccharides (e.g. cellulose, starch)

Question 6

lipids: saturated fats and oils, and unsaturated fats and oils

Answer 6

• fats => provide energy => oils, fats, butter, margarine, cream
• fats are solid at room temperature and of animal origin e.g. butter; made of glycerol and fatty acids
• oils are liquid at room temperature and of plant origin e.g. canola oil, olive oil, sunflower oil, coconut oil, vegetables, peanut oil
• functions: provides the body with energy, acts as insluation below surface of skin, protect bones & organs, maintain structure/health of body cells
  ==> polyunsaturated fats; reduce risk of heart disease when replacing saturated fats e.g. polyunsaturated margarine rather than butter, omega-3 fats or fish oils; added to products like bread and milk
  ==> saturated fats; derived from animals and plants… usually associated with increased risk of heart disease e.g. butter, cream, margarine, palm oil, coconut oil, fat on meat
  ==> monounsaturated fats; olive oil, canola oil, margarines made from them, nuts, seeds, olives, avocados; lowers levels of bad cholestrol
  ==> trans-fats; unsaturated fats that behave more like saturated fats; found naturally in dairy products and meats, also produced during hydrogenation (process where liquid vegetable oils converted to semi-solid fats), often in cakes, biscuits, pastries, takeaway food; not too good
  ==> cholestrol; waxy substance needed by the body in small amounts for manufacture of bile acid and in the production of Vitamin Dl found in cells protecting the brain and nervous system

Question 7

Macronutrient requirements depending on age and lifestyle (for protein, carbohydrates, lipids)

Answer 7

highest in adolescence or pregnancy

• adolescent: ensure health growth and weight gain; period of rapid growth, increased physical activity => can be time of iron deficiency and anaemia (particularly in girls due to menstruation and poor diets)
• adolescent RDI:
  -> protein: girls = 45 g, boys = 65 g
  -> calcium: girls = 1300 mg, boys = 1300 mg
  -> iron: girls = 15 mg, boys = 11 mg

Question 8

vitamins

Answer 8

• (MEMORISE AT LEAST 4) functions of vitamins: cell division, growth, energy source, eyesight functioning, healing wounds, functioning of nervous system, blood clotting, healthy skin, metabolism of proteins fat and carbohydrates, providing resistance to infection, muscle tone, assist in the absorption of minerals
  ==> fat soluble: A, D, E, K
  ==> water soluble: B, B1, B2, B3, B5, B6, B12, C

Question 9

minerals

Answer 9

• required to stay healthy, involved in chemical reactions in the body including metabolism, cell growth and repair, nerve and muscle function
• functions: form a part of many hormones and enzymes, essential for health and growth, maintenance of teeth and bones
• e.g. calcium, magnesium, potassium, sodium, zinc etc.
• trace minerals (much smaller amounts) e.g. copper, iodine, manganese, selenium etc.