unit 1 nutrition (does not currently contain deficiency/excess of macronutrients, no info on fluoride, iodine or phosphorus)

fn AQA GCSE

What are the functions of protein?

Repair, growth, maintenance (e.g. of hair, skin, nails etc), secondary source of energy and provision of hormones, enzymes, antibodies and amino acids

How much protein is recommended for adult men and women each day?

Men: 55g

Women: 45g

Factors affecting protein needs

Pregnancy, breastfeeding (both need more protein)

What are the two types of protein?

High biological value (HBV) and low biological value (LBV)

What is high biological value protein?

Protein foods that contain all of the essential amino acids

What is low biological value protein?

Protein foods that do not contain all of the essential amino acids

How many essential amino acids are there?

8 for adults, 10 for children

What is protein complementation?

Combining multiple low biological value foods in a meal to provide all the essential amino acids

Sources of high biological value protein

Meat, fish, milk, eggs, dairy (e.g. cheese), soya beans

Sources of low biological value protein

Nuts, seeds, lentils, beans

High biological value protein alternatives

Tofu, tempeh, textured vegetable protein (TVP), mycoprotein

Examples of protein complementation

beans on toast, hummus on pitta bread, lentil soup

What are fats that are liquid at room temperature called?

Oils

Functions of fats

Provide store of energy in adipose tissue under skin, layer of insulation under skin, protective cushion of fat around bones and kidneys, provide fat soluble vitamins (A, D, E, K)

What do fats break down into?

Glycerol and 3 fatty acids (triglyceride structure)

What are the 3 types of fat?

Saturated, monounsaturated and polyunsaturated

Structure of different types of fat

Saturated have no double bonds, monounsaturated have one double bond, polyunsaturated have more than one double bond

Sources of saturated fat (usually solid at room temperature)

Butter, meat (e.g. bacon, sausages), cheese, chocolate

Sources of monounsaturated fat (usually soft or liquid at room temperature)

Olive oil, avocados, nuts, peanut butter

Sources of polyunsaturated fat (usually soft or liquid at room temperature)

Oily fish, sesame oil, seeds

How much of our food energy should come from fats?

Maximum 35%, maximum 15% from saturated fats

What are essential fatty acids?

The two fatty acids which the body can’t make

Why are saturated fats labelled bad and unsaturated fats labelled good?

Saturated fats raise LDL (bad cholesterol) and lower HDL (good cholesterol), unsaturated raise HDL and lower LDL. However as fats are very energy dense not too many should be eaten of either type

What are the functions of carbohydrates?

Main source of energy in the diet, help body get rid of waste products (dietary fibre)

What are the two groups of carbohydrates?

Simple sugars and complex carbohydrates

What are the two types of sugars?

Monosaccharides and disaccharides

What are the sources of monosaccharides?

Glucose (ripe fruits and veg), fructose (fruits, honey) and galactose (milk)

What are the sources of disaccharides?

Maltose (barley, biscuits), lactose (milk, yogurt) and sucrose (caster and brown sugar)

Sources of complex carbohydrates

Polysaccharides

Sources of polysaccharides

Starch (oats, potatoes), dietary fibre/NSP (fruits, veg), pectin (oranges, carrots), dextrin (formed when starchy foods are baked/toasted)

Function of dietary fibre

Helps with digestion and producing soft, bulky faeces

How much saturated fat should be eaten daily?

Maximum 20g for adults

How much unsaturated fat should be eaten daily?

Maximum 50g for adults

How much sugar should be eaten daily?

Maximum 30g for adults and maximum 5% of daily energy intake

How much complex carbohydrate is needed daily?

Maximum 225-325g per day

How much fibre is needed daily?

Maximum 30g for adults, children need a little less

What are the fat soluble vitamins?

Vitamins A, D, E and K

What are the water soluble vitamins?

Vitamins B1 (thiamine), B2 (riboflavin), B3 (niacin), B9 (folate), B12 (cobalamin), C (ascorbic acid)

Function of vitamin A

Keeps skin healthy, growth, healthy eyesight (especially night vision), antioxidant, helps maintain good immune system

Sources of vitamin A

Retinol (kidney, oily fish, liver) and beta carotene (spinach, kale, orange/yellow/red fruit and veg)

Vitamin A deficiency

Night blindness, can lead to total blindness and permanent eye damage, stunted growth in children, skin and mucus membranes become dry and infected

Vitamin A excess

Rare but can become poisonous due to building up in the liver and can damage development of unborn baby in pregnant women

Vitamin D function

enables calcium to be absorbed during digestion, helps calcium be deposited in bones and teeth

Vitamin D sources

Can be produced naturally from contact with sunlight, oily fish, eggs, butter, meat

Vitamin D deficiency

Children’s bones and teeth will not strengthen and legs will bend under weight of body (rickets), adults bones may weaken and become brittle (osteomalacia), osteoporosis

Vitamin D excess

Rare but can lead to excess calcium being absorbed which can damage kidneys and other organs, especially in babies and young children

Vitamin E function

Antioxidant

Vitamin E sources

Tocopherol - nuts, seeds, olive oil, plant foods

Vitamin E deficiency

Rare

Vitamin E excess

Rare

Vitamin K function

Enables blood clotting

Vitamin K sources

Phylloquinone - green leafy vegetables, liver, cheese, green tea

Vitamin K deficiency

Very rare in UK but in newborn babies can cause uncontrollable bleeding

Vitamin K excess

Can’t have too much

Vitamin B1 name and function

Thiamine - enables energy to be released from carbohydrates in cells during respiration

Vitamin B1 sources

Milk, cheese, eggs, fortified breakfast cereals

Vitamin B1 deficiency

Leads to condition called beri-beri in which nerves and muscles are affected and causes problems with memory, concentration and heart rate

Vitamin B2 name and function

Riboflavin - enables energy to be released from carbohydrates, fats and proteins from cells during respiration

Vitamin B2 sources

Yogurt, eggs, fortified breakfast cereals

Vitamin B2 deficiency

Rare but can cause sores at corner of mouth as it is needed to help maintain healthy skin

Vitamin B3 name and function

Niacin - enables energy to be released from food in cells during respiration

Vitamin B3 sources

Beef, pork, eggs, cow milk

Vitamin B3 deficiency

Pellagra - causes diarrhoea, dermatitis, dementia as lack of B3 prevents brain and nervous system working properly

Vitamin B9 name and function

Folate/folic acid - works with B12 to make healthy red blood cells, helps reduce risk of developing central nervous system defects in unborn babies such as spina bifida

Vitamin B9 sources

Green leafy vegetables, peas, chickpeas, wholegrain rice

Vitamin B9 deficiency

Can cause spinal cord defects in unborn babies and lead to megaloblastic anaemia (where red blood cells become enlarged) as without B9 red blood cells do not develop to correct size

Vitamin B12 name and function

Cobalamin - works with folate (B9) to make healthy red blood cells and keeps nerve cells healthy

Vitamin B12 sources

Meat, fish, cheese, fortified breakfast cereals

Vitamin B12 deficiency

Can be stored in liver for 2+ years so rare, but vegans may become deficient as cobalamin does not occur naturally plants, leads to pernicious anaemia

Vitamin C name and function

Ascorbic acid - antioxidant, helps body absorb iron in small intestine, needed to maintain connective tissue which binds the body cells together in the skin, muscles, blood vessels etc

Vitamin C sources

Citrus fruits, cabbage, broccoli, blackcurrants

Vitamin C deficiency (4)

Iron not absorbed so leads to anaemia, bleeding from small blood vessels under skin and in gums leads to red spots under skin and loose teeth (due to connective tissue breaking down), wounds take long time to heal and scar tissue may break open (due to connective tissue not being made properly), this all leads to scurvy which can result in death

Which vitamins are antioxidants?

Vitamins A, C and E

What do antioxidants do?

Prevent free radicals from damaging body’s cells - free radicals can cause inflammation, cancer and heart disease

Function of calcium

Helps make teeth and bones strong, needed to make nerves and muscles work properly and to allow blood to clot over a wound

Sources of calcium

Milk, cheese, yogurt, green leafy vegetables

Calcium deficiency

Bones and teeth weaken, bones bend under weight of body, if caused by vitamin D deficiency will lead to rickets in children and osteomalacia in adults, muscles and nerves won’t work properly, blood won’t clot properly over wounds

Calcium excess

Very rare but can lead to kidney failure

Function of iron

Needed to make haemoglobin in red blood cells which allows them to carry oxygen

Iron sources

Red meat, wholemeal bread, lentils, egg yolks

Iron deficiency

Leads to iron deficiency anaemia which causes tiredness, lack of energy, pale skin complexion, weakness, this is because oxygen is required for respiration, which releases energy, and if there is not enough iron then there’s not enough oxygen for cells to release energy

Who needs more iron and why?

Pregnant women need more iron as unborn babies build up an iron store during the last 3 months of pregnancy

Iron excess

Poisonous

Sodium function

Controls amount of water in body, helps control nerves and muscles, helps body use energy

Sodium sources

Salt, foods that have added salt e.g. cheese, crisps, bacon etc

Sodium deficiency

Muscle cramps, can be caused to salt loss due to excess sweating or vomiting/diarrhoea

Sodium excess

High blood pressure (hypertension), puts strain on heart and kidneys as body retains too much water and this increases blood volume

What is the recommended intake of salt for adults?

Maximum 6g per day

What is energy needed for in the body?

Keeping warm, movement, growth, chemical reactions etc

How much of our daily energy intake should come from carbohydrates?

50% - it’s the main source, no more than 5% from free sugars

How much of our daily energy intake should come from fats?

Maximum 35% - secondary energy source

How much of our daily energy intake should come from protein?

15% - third source of energy

What does it mean to have an energy imbalance?

Energy intake is greater than energy output or the other way round

What happens if you consume too little energy?

Weight loss

What happens if you consume too much energy?

Weight gain

What does your daily energy need depend on?

Basal metabolic rate (BMR), physical activity level (PAL) and life stage (e.g. pregnant, old age, teen)

What is basal metabolic rate?

The amount of energy needed to stay alive and perform basic bodily functions e.g. breathing

What does your basal metabolic rate depend on?

Age (younger = higher), body size (larger = higher), gender (male = higher) and PAL (higher = higher)

What is physical activity level?

How active or inactive a person is, effects their BMR

What nutrients, vitamins and minerals do elderly people need more of?

Protein, unsaturated fats, carbohydrates, all vitamins minerals