Food Properties

Function of Protein:

• Grow the body from a baby into an adult. Also for nail, hair growth.
• Repair the body when it is injured or ill. Replaces skin and red blood cells regularly.
• Energise the body as well as gaining energy from fats and carbohydrates.
• Hormones- make you grow and reproduce.
• Enzymes - help digest your food.
• Antibodies - help your immune system fight infections from bacteria and viruses.

Importance:

• Essential amino acids are amino acids that needed- 8 for adults and 10 for children.
• High Biological Value proteins contain all of the essential amino acids. (meat,eggs,fish, quinoa)
• Low Biological Value proteins are missing one or more of the essential amino acids.
• (cereals, nuts, seeds, beans, lentils, gelatine).
• Protein complementation A mixture of LBV proteins provide all essential amino acids.
• (beans on toast, rice & bean salad, lentil soup).

Protein Alternatives:

• Manufactured products that are used as alternatives to meat.
• Have high protein content and a low fat content. They have little flavour on their own.
• Tofu (soya bean curd) / Tempeh (fermented soya beans) / Mycoprotein (Quorn- fungus).

Effects of protein deficiency:

• Lack of height growth- the body can't grow without the right quality/quantity of nutrients.
• Hair loss- protein creates hair, if there is a protein deficiency, it will be used somewhere else.
• Poor skin condition- skin contains protein and a protein deficiency it will weaken.
• Infections- lack of protein for the immune system, preventing it from stopping infections.
• Poor digesttion- a protein deficiency causes changes in the digestive system.

Effects of protein excess:

• Protein contains nitrogen which is excreted from the body.
• If there is a protein excess the liver and kidneys have to work harder to get rid of the nitrogen.

Functions:

• Energy- provide a store of energy in the adipose tissue under the skin.
• Insulation- to insulate the body from the cold and help it stay warm.
• Protection- protect bones and kidneys by providing them with a protective cushion.
• Nutrition- give the body fat soluble vitamins A,D,E and K.

Unsaturated fats- fatty acids found mainly in liquid oils (olive, rapeseed, oily fish, nuts, seeds).

Saturated fats- fatty acids found mainly in solid fats (butter, coconut, chocolate, palm oil).

Monounsaturated fats- fatty acids found both in solid fats and liquid oils (red meat, avocados).

Fat- macronutrient that supplies the body with energy.

There are two essential fatty acids that are needed by adults and children.

They are mainly found in oily fish, plant and seed oils, eggs and fresh meat.

Visible solid animal fats: butter, lard, suet, ghee, fat on meat.

Invisible solid animal fats: cheese, butter in cakes, sausages, processed ready meals.

Visible solid plant fats: white vegetable fats, vegetable fat spreads, coconut cream, cocoa butter.

Invisible solid plant fats: ready-made curries, food made with vegetable oil, chocolate.

Visible liquid animal oils: cod liver oil, oily fish (mackerel, sardines)

Invisible liquid animal oils: milk, cream, egg yolk, oily fish.

Visible liquid plant oils: nut and seed oils (sunflower, rapeseed, sesame, corn, olive, almond)

Invisible liquid plant oils: pumpkin/sunflower seeds, nuts, fruits, veg fat spreads, fried foods.

Effects of fat deficiency:

• Weight Loss- the body will use the store of energy from fat cells and it won't be replaced.
• Temperature Change- there won't be enough fat to insulate the body from the cold.
• Weak Skin Protection- the body will bruise easily as there isn't enough adipose tissue.
• Lack of Vitamins- the body won't recieve enough vitamins A, D, E, K.

Effects of fat excess:

• If the energy isn't used in physical activity, it will be stored in the body, increasing weight.
• Eating a high level of saturated fats can lead to coronary heart disease.

Functions:

• Energise the body- carbohydrates are the main source of energy in our diet.
• Get rid of waste products- dietary fibre helps produce soft, bulky faeces.

Monosaccharides - made of one sugar molecule. 3 types are glucose, fructose, galactose.

• Glucose- ripe fruits & veg. / Fructose- fruit & veg, honey / Galactose- milk from mammals.

Disaccarides - made up of two sugar molecules. 3 types are maltose, sucrose, lactose.

• Maltose- barley, malt extract / Sucrose- sugar / Lactose- yogurt, evaporated milk, cheese.

Polysaccharides - plants produce several during photosynthesis, don't taste sweet. 3 types are:

• Starch- cereals, bread, pasta, cakes, sweet potatoes, parsnip, peas, seeds, quinoa.
• NSP- bread, flour, peas, beans, lentils, seeds, nuts.
• Pectin- oranges, lemons, apples, apricots, carrots, plums.
• Dextrin- baked/toasted bread, cakes, biscuits.

Effectsof deficiency:

• Fatigue- the level of glucose drops and cells throughout the body won't have enough energy.
• Weight Loss- the body will start to use energy in fat cells which will mean weight loss.
• Severe Weakness- the body makes sure that all vital organs recieve energy instead of muscles

Effects of excess:

• The carbohydrate may be converted into fat and stored in the body, leading to obesity.
• Processed carbohydrate are broken down quickly and can cause a rise in sugar levels.
• Intrinsic sugar found naturally in foods can lead to tooth decay.
• Free sugars from processed foods can also lead to tooth decay.

Main Food Sources:

• Retinol- whole/semi skimmed milk, cheddar cheese, egg yolk, butter, oily fish, liver, kidneys.
• Beta Carotene- cabbage, spinach, kale, lettuce, peas, carrots, apricots, mango, sweet potatoes

Function:

• Keeps ths skin healthy and helps children grow.
• Enables the eye to see in dim light. / Produces mucus for mucus membranes.

Effects of deficiency:

• Lack of growth- children need all nutrients.
• Infection- bacteria and viruses can enter the body more easily.

Effects of excess:

• Poisonous- excess can build up in the liver and start to poison the body.
• Damage unborn baby- pregnant women advised not to eat vitamin A rich foods.

Main Food Source:

• Cholecalciferol- oily fish, meat, eggs, butter, liver, vegetable fat spreads, breakfast cereals.

Function:

• Enables calcium to be absorbed from the small intestine and deposited in the bones and teeth.

Effects of deficiency:

• Weak bones- children's bones and teeth won't strengthen (rickets) because of lack of calcium.
• Weak bones- adult's bones may start to weaken and break easily (osteolmalcia).

Effects of Excess:

• Organ damage- excess calcium being absorbed leading to damage to kidneys in children.

Vitamin K

Main food source:

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

Function:

• Part of the process that enables blood to clot when the body is injured.

Effects of Deficiency: (very rare)

• Sometimes occurs in new-born babies, so they are given a dose of Vitamin K when born.

Vitamin E

Main Food Source:

• Tocopherol- soya, corn oil, olive oil, nuts, seeds, wheatgerm, vegetable fat spreads.

Main Food Source:

• Thiamine- pork, milk, cheese, eggs, vegetables, fruits, wholemeal bread, cereals, flours.

Function:

• Enables energy to be released from carbohydrate in body cells during respiration.

Effects of Deficiency:

• Beri-beri- where nerves and muscles are affected leading to memory, concentration problems.

Main Food Source:

• Riboflavin- milk, eggs, cereals, rice, mushrooms.

Function:

• Enables energy to be released from carbohydrate, fat and protein during respiration.

Main Food Source:

• Niacin- beef, pork, wheat flour, maize flour, eggs, milk.

Function:

• Enables energy to be released from food in body cells during respiration.

Effects of deficiency:

• Pellagra- has 3 symptoms of diarrhoea, dermatitis, dementia due to nervous system damage.

Main food source:

• Folate- brussel sprouts, broccoli, kale, spinach, peas, chickpeas, asparagus, wholegrain rice.

Function:

• Works with vitamin B12 to make red blood cells healthy.
• Helps reduce the risk of developing defects in the central nervous system such as spina bifida.

Effects of deficiency:

• Anaemia- can lead to megoblastic anaemia where red blood cells enlarge without folate, which prevent them from passing through narrow capilliaries.
• May lead to defects in the spinal cord in unborn babies.

Main food source:

• Cobalamin- liver, meat, fish, cheese, yeast, breakfast cereals.

Function:

• Works with vitamin B9 to keep red blood cells healthy.
• Keeps nerve cells healthy.

Effects of deficiency:

• Anaemia- deficiency can lead to pernicious anaemia as the small intestine don't produce a particular protein that enables the Vitamin B12 to be absorbed.

Vegans have to be careful that they don't become deficient as they don't have any animal food.

Vitamin B12 can be stored in the liver for 2+ years.

Main food source:

• Ascorbic Acid- oranges, lemons, grapefruit, blackcurrants, kiwi, cabbage, broccolis, potatoes

Function:

• Needed to help body absorb the mineral ion in the small intestine.
• Needed to maintain connective tissue which binds that body cells together.

Effects of deficiency:

• Anaemia- iron isn't absorbed which can lead to iron deficiency anaemia.
• Bleeding- small blood vessels bleed as connective tissue starts to break down.
• Wounds- connective tissue can't be made properly to heal a wound and can open up scars.

Main Food Sources:

• Milk, cheese, yogurt, canned fish, green leafy vegetables.

Function:

• The main mineral on our body, making our teeth and bones strong and maintaining our nerves.

Effects of deficiency:

• Weak Bones- the bones won't reach peak bone mass and are more likely to weaken and break.
• Weak Bones- if the cause is lack of vitamin D the deficiencies will be rickets and osteomalacia.
• Osteoporosis- where the bones are losing minerals after reaching peak bone mass.

Main food source:

• Red meat, kidney, liver, wholemeal, green leafy vegetables, egg yolk, dried apricots, lentils.

Function:

• Iron is needed to make haemoglobin in red blood cells to carry oxygen to all body cells.

Effects of deficiency:

• Weakness- can lead to iron deficiency anaemia which means not enough oxygen for the cells.

Effects of excess:

• Poisonous- too much iron is poisonous to the body.

Main food sources:

• Salt, cheese, stock cubes, snack foods, gravies, canned fish, bacon, ham, baking powder.

Function:

• Controls the amount of water in the body. Helps control nerves and muscles.

Effects of deficiency:

• Muscle problems- without the sodium to control nerves, the muscles will cramp and lose salt.

Effects of excess:

• High blood pressure- the excess sodium means the body retains too much water which increases the volume of blood and the heart has to work harder to pump it round the body.

Main Food Source:

• Fish and seafood, water supplies, tea.

Function:

• To strengthen the bones and enamel in the teeth to prevent tooth decay.

Effects of deficiency:

• Tooth decay- the enamel won't be as strong so acid from bacteria can dissolve more easily.

Effects of excess:

• Teeth dicolouration- too much fluoride can affect the normal mineralisation of the teeth.

Iodine

Main food source: Seafood, vegetables, milk, dairy foods.

Function:

• Produce the hormone thyroxin in the neck which controls the metabolic rate of the body.

Effects of deficiency:

• Goitre- swelling in the neck as the thyroid gland picks up iodine in the bloodstream.
• Cretinism- babies born with permanent brain damage.

Phosphorous

Main food source: found in a wide range of foods.

Function:

• Mineralises the bones and teeth. Essential for energy release. Makes up phospholids.