Transcript Slide 1

What do you know already?
Nutrients
 What are nutrients?
 Why do we need certain nutrients?
 What are the main ones?
 What is a balanced diet?
 What diseases and illnesses can be caused if a diet
is poor?
 What is a MACRO nutrient?
 What is a MICRO nutrient?
 What is nutrient intake influenced by?
Guidelines
 The eat well plate is consistent with the Government’s Eight tips
for eating well, published in October 2005, which are:
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1. Base your meals on starchy foods
2. Eat lots of fruit and vegetables
3. Eat more fish
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
8. Don’t skip breakfast
CARBOHYDRATES
 Simple- sugars- fructose (fruit), sucrose (complete sugar),
lactose (milk).
 Complex- starches and fibre (NSP- cellulose- vegetables and
plants)
 Monosaccharide's (glucose, fructose and galactose),
Disaccharides (sucrose, lactose, maltose), Polysaccharides
(starch).
 Macro nutrient
 Main function is for energy and muscle functioning.
 Excess stored as fat, high sugar diet leads to tooth decay.(
Intrinsic (naturally occurring) and Non-intrinsic sugar (added
sugars)
 Atkins diet- low carbohydrate.
 All carbohydrates are converted to glucose during digestion.
QUESTIONS- carbohydrates
 1) what is the main function of carbohydrate?
 2) What are the sources of carbohydrate?
 3) What is a simple, and a complex
carbohydrate? Give an example of each?
 4) Which should we have more of?
 5) what percentage should we roughly have
of each?
 6) What is dietary fibre? What is it for?
 7) Where can we get a supply of fibre from?
3 categories of carbohydrate.
 Monosaccharide- Fructose and glucose.
 Disaccharides- sucrose and lactose
 Polysaccharides- starch
 These contain different amounts of Carbon,
hydrogen and oxygen atoms which make up
the carbohydrate.
Dietary conditions associated with
carbohydrates.
 High sugar- dental
decay
 Low fibre- Diverticulitis
Presentation in pairs.
 Select one of those dietary conditions, and be
prepared to feedback to the group on your findings.
 Include How condition is caused
 What happens
 What diet is necessary
 What should be avoided
 What can be done to prevent it
PRACTICAL- Carbohydrates.
 Plan, prepare, cook and serve a high energy
dish.
 It could include any of the following:
 Potatoes
 Pasta
 Rice
 Bread.
DRV’s
 These set out the requirements for different
nutrients, for a healthy group of the
population. They do not have to be followed
exactly, they are just a guide.
 EAR- estimated average requirement is used
to determine energy intakes needed.
 RNI- reference nutrient intake for 97% of the
population, one most followed.
 LRNI- lower- 3% of population will follow this.
 RDA- recommended daily allowance.
FAT
 Main function- energy and warmth, structure and
function of body cells, protects organs.
 In Infancy, it is also for normal brain development.
 Excessive fat intake- obesity, high blood pressure,
colon and other cancers, CHD.
 Structure of fat- building blocks called fatty acids,
composed of carbon and hydrogen atoms.
 Saturated, monounsaturated, polyunsaturated fats.
(These all have differing hydrogen atoms.)
 In some foods- fat is visible i.e.. Meat. Eggs- invisible.
Classification
 Saturated- usually solid at room temp.Animal sources- dairy
and red meat. No double bonds of carbon in the chain.
 (liver uses saturated fat to manufacture cholesterol)
 Monounsaturated- plant sources- vegetable and nut oils. one
double bond of carbon in chain.
 Polyunsaturated- plant- sunflower and fish oil. They have more
than one double bond. These lower blood cholesterol levels.
 Using your books, draw out the chemical structure of the 3
different fats.
FATS
 Omega 3/6 fatty acids- essential fatty acids, polyunsaturated. Found in
oily fish and pumpkin seeds and green leafy vegetables. Very good for
us, help with brain development.
 Find out the following: What are Trans fatty acids? What is
Hydrogenation?
 Trans Fatty acids- these have hydrogen atoms on opposite sides of
the double bond, these fats are created by a process called
Hydrogenation. This is used in the food industry to turn vegetable oil
into a solid substance. It improves the shelf life of a product. During
hydrogenation, vegetable oils are hardened by processing them with
hydrogen gas.
 Essential fatty acids must be consumed in the diet as the body cannot
make them. They are for reducing CHD, development of the nervous
system, blood clotting and metabolism.
Cholesterol
 This is a type of fat, but it does not produce
any energy. It is found in all animal cells and
tissues but is not found in vegetables or
plants. Cholesterol has an essential role in
the structure of cell membranes, and
production of bile. The liver manufactures
cholesterol.
 There are 2 types of cholesterol- LDL- low
density lipoprotein and HDL. HDL protect
against heart disease, LDL can cause it.
POSTER WORK
 Complete a poster on either CHD or obesity.
 Include-
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What condition is
How it is caused
Diet recommended
Foods to avoid
Examples of suitable meals and dishes.
Meal planning
 Plan, prepare, cook and serve a low fat dish.
Malnutrition.
 Bad nutrition/ under nutrition.
 Symptoms of mal nutrition include tiredness, slow growth in
children, brittle nails, dry and scaly skin, slow wound healing,
susceptibility to infection. Individuals can suffer reduced muscle
strength, depression and self neglect.
 Groups at risk- babies and children, the elderly and other adults,
people who abuse drugs or alcohol, people with eating
disorders, people with illnesses and disease, people on a low
income.
PROTEIN
 About 17% of the body is made up of protein.
 All proteins are made up of carbon, hydrogen, oxygen and
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nitrogen, and most proteins also contain sulphur and some
phosphorus. These elements are arranged into units called
amino acids.
Amino acids are the building blocks of protein, essential
(indispensable) amino acids cannot be made by the human
body, non-essential (dispensable) can be.
If a protein food contains a lot of the indispensible amino acids it
is said to have a high biological value (HBV), if it is low in any of
the indispensable amino acids, it is said to have a low biological
value (LBV)
LBV- plant sources- pulses, beans and lentils.
HBV- animal sources- meat, fish and dairy.
Average daily intake of protein for men is 85g and 62g for
women.
PROTEIN
 You can use complementary proteins in cooking, meaning that LBV
and HBV proteins can be put together in dishes.
 Think of some dishes?
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Functions of protein:
Growth of body cells.
Maintenance and repair of body cells.
To provide a source of energy.
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Novel sources of protein; Find out what they are?
TVP
Tofu
Soya
Quorn
 Find out what the symptoms of deficiency are?
Meal planning
 Plan, prepare, cook and serve a dish using a
protein alternative:
 Quorn
 TVP
 Soya
Vitamins- Micro nutrients.
 Main functions Teeth and bones
 Muscle formation
 Blood
 Skin
 Basic functioning of bodily organs and functions
 BUT- different vitamins have differing functions.
TASK
 Find out what a Fat soluble and a Water
soluble vitamin are?
 Water soluble dissolve in water so are lost in
cooking, Fat do not. The body stores fatsoluble vitamins, so they do not need to be
taken in daily.
Fat-soluble vitamins (A,D,E,K) (stored in the
fat in our body, they do not dissolve in water)
 VITAMIN A
 The 2 sources of vitamin A are Animal and vegetable. In the UK
diet, 75% of our intake of vitamin A is supplied in the form of
retinol and 25% as Beta-carotene.
 Vitamin A aids vision, involves with the maintenance of the
immune system and is an ANTIOXIDANT which reduces the risk
of CHD.
 Night blindness is associated with a deficiency in Vit A.
 Retinol can however be toxic in large amounts.
VITAMIN D
 The main source of vitamin D is sunlight. Dietary forms are
dairy, oily fish and eggs.
 Functions of vitamin D are development of strong bones and
teeth, prevention of osteoporosis in later life, promoting the
absorption of calcium.
 Rickets is a deficiency of vitamin D that occurs in babies and
toddlers. In adults this is caused osteoporosis or osteomalacia.
 Vitamin D can be toxic if consumed in large amounts.
VITAMIN E
 This is an ANTIOXIDANT.
 Foods that include Vitamin E are olive oil, nuts, egg yolk and
prawns and salmon.
 Vitamin E protects body tissue from damage, it prevents cancer
and heart disease, it is also important in the formation of red
blood cells.
 Deficiency includes slow wound healing and lack of energy.
VITAMIN K
 This is a fat-soluble vitamin that can be stored in the liver.
 Good supplies of vit K are found in green leafy vegetables and
veg oil and cereal. Small amounts of vit k are found in red meat
and milk.
 Vitamin K is for blood-clotting and overall bone health.
 A deficiency can lead to bruising and bad bleeding. In
pregnancy, insufficient vitamin K can reach the foetus across
the placenta.
Water-soluble vitamins (B group and C) (not
stored in our body, needed daily)
 VITAMIN B1 (THIAMIN)
 Lean meats, milk, cheese and cereals are good sources of
thiamin. Thiamin is added to some cereals as the processing of
cereals can destroy the vitamin.
 Thiamin is important in the process of energy release. It is also
necessary for the transmission of nerve signals between the
brain and the spinal cord and for normal growth and
development.
 Deficiency in thiamin leads to nerve damage and eventually
death.
VITAMIN B2 (RIBOFLAVIN)
 It is destroyed by light. It is found in poultry, lean meat, eggs,
fish and milk. It is also present in leafy green vegetables.
 Riboflavin is essential for releasing energy from food, vital for
growth and development and helps keep skin, eyes and nervous
system healthy.
 Deficiency in this results in skin disorders, bloodshot eyes and
poor growth.
VITAMIN B3 (NIACIN)
 This is also referred to as Nicotinic acid.
 Niacin is found in a wide range of foods including poultry, milk,
eggs and broccoli.
 Niacin is essential in the metabolism of carbohydrates, fats and
proteins, and to produce energy for body growth, it maintains
healthy skin and keeps the digestive and nervous system
working well. It is essential for the production of hormones
including oestrogen and insulin.
 A deficiency leads to dermatitis and dementia.
VITAMIN B6 (PYRIDOXINE)
 This is lost in cooking water and is destroyed by heat, sunlight
and air.
 Vitamin B6 is found in lean meat, eggs, chicken and fish,
wholegrain and cereal.
 It is required for the formation of red blood cells, it has an
important role in the immune system and is required for the use
and storage of energy from proteins and carbohydrates.
 A deficiency with it has been associated with skin disorders and
anaemia.
VITAMIN B12
 This is found mostly in animal products including eggs, shellfish,
poultry and dairy produce. There is no B12 in vegetables or
cereals.
 Vitamin B12 is used in the metabolism of fats and proteins, and
the maintenance of the nervous system. It is also needed in the
manufacture of red blood cells.
 A shortage leads to anaemia.
 FOLIC ACID:
 Daily supplies are needed to maintain health.
 Many green vegetables contain folic acid.
 It is needed to prevent congenital abnormalities in babies, and is
required for the formation of red blood cells.
VITAMIN C (Ascorbic acid)
 The main source of vitamin C is fresh fruit and vegetables,
especially citrus fruit.
 It is required for growth, it is essential for the repair of body
tissues and formation of red blood cells, it is also vital in the role
of the immune system.
 Gum problems will occur if an individual is deficient in this
vitamin.
 Vitamin C is destroyed in cooking and chopping. Fruit and
vegetables are better eaten raw to retain vitamin C content.
Antioxidant vitamins (E/C)
 These prevent CHD and high cholesterol.
 These are a group of substances which protect
others from the effect of oxidation. They also protect
the body against free radicals (by-products that
result, when the body converts food to energy)
 Antioxidants have been shown to prevent CHD by
inhibiting the development of atheroma (cholesterol)
VITAMIN
FUNCTION
SOURCE
DEFFICIENCY
Vit A (beta
carotene)
Growth and repair,
skin, reduce
cancer, protect
against infection.
Carrots, sunlight
Susceptive to
infection, rough
skin, loss of
appetite.
Vit B1 (thiamin)
Metabolism,
generates energy,
digestion, nervous
system function
Green veg, red
meat
Loss of appetite,
insomnia, loss of
weight
Vit B2 (riboflavin)
Formation of red
blood cells and
antibodies, vision
As above
Retarded growth,
Dermatitis, oily skin
Vit B3 (niacin)
Improves
As above
circulation, reduces
cholesterol and
high blood
pressure
Head ache,
fatigue, skin
disorder
Vit C (ascorbic
acid)
Essential for
healthy teeth,
heels wounds,
prevents scurvy
Citrus fruit
Soft and bleeding
gums, loss of
appetite
Vit D
Absorb of calcium
Bones and teeth
Milk, cheese,
sunshine
Bone softening
Muscle weakens
Vitamin supplements
 Groups who may require supplements:
 Women who are planning to get pregnant.
 People with limited exposure to sunlight.
 Vegans
 People who are malnourished
 Elderly people
 Athletes in training
Questionnaire
 Devise a questionnaire for year 7 pupils, to
evaluate their intake of fruits and vegetables.
Meal planning
 Plan, prepare, cook and serve a vegetable
main dish or fruit dessert.
Minerals
 Some minerals are needed in larger amounts than others, and
these are called the major minerals- these are:
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Iron
Calcium
Phosphorus
Magnesium
Sodium
Potassium
Zinc
Chloride
 Others are needed in smaller amounts and these are called
trace elements.
Functions of minerals
 Formation of the skeleton and teeth
 Control body fluids and cells
 Clotting of blood
 Normal functioning of muscles and nerves.
 Find out the main functions of IRON and CALCIUM, what
other vitamins are needed in the absorption of each? What
are the sources of these nutrients?
IRON
 A healthy adult body contains about 4g or iron. Iron is stored in
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the liver, spleen and bone marrow.
Iron is found in plant sources (non-haem iron) and animal
sources (haem-iron).
Only about 10% of the iron consumed is absorbed by the body.
Before iron can be absorbed, it needs to be changed to ferrous
iron, vitamin C is required in this process.
Iron is needed for the formation of haemoglobin in red blood
cells, energy metabolism, and function of the immune system.
A lack of iron leads to anaemia.
CALCIUM AND PHOSPHORUS
 Calcium and phosphorus account for about 75% of the mineral
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elements in the body.
Calcium is found in milk, cheese, yogurt and other dairy
products. Vitamin D promotes the absorption of calcium.
Calcium is essential for building and maintaining healthy teeth
and bones, it is required for the contraction of muscles, blood
clotting and activity of several enzymes.
If an individual is deficient in calcium, symptoms will include
muscle twitches, reduced bone density and rickets and
osteoporosis.
Main sources of phosphorus are milk and milk products.
Phosphorus is essential for bone and teeth formation, and
release of energy from cells.
POTASSIUM, ZINC AND
MAGNESIUM
 Main sources of potassium are bananas, potatoes and
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vegetables.
Potassium has a beneficial blood-pressure lowering effect.
Zinc is found in many foods including red meat and fish.
It is essential for the functioning of the immune system.
A deficiency of zinc can lead to retarded physical and mental
development in teenagers.
Magnesium is present in most vegetables.
It is needed for nerve, muscle and brain functions.
FLUORIDE, SODIUM AND IODINE
 Fluoride is found in many foods. Drinking water is an important
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source of fluoride.
Fluoride contributes to the maintenance of bone health.
It also protects the teeth.
Sodium also known as salt is found in processed foods.
Sodium is involved in the transmission of nerve impulses and
muscle contraction.
Low intakes of sodium result in muscle cramps.
Rich sources of iodine are seafood's, eggs and milk.
Iodine is required for energy metabolism.
Meal planning
 Plan, prepare, cook and serve a dish high in
calcium or iron.
 Dish chosen………………….
 Reasons for choice:
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Energy
 Energy is required for every process in the body.
 Energy is measured in KJ or Calories.
 Body needs energy to keep warm, maintain breathing, digest
and store food, fight infection and create body cells.
 Sources of energy are foods that are high in fat and sugar.
 Find out the calories burnt doing various activities.
 Energy intake must equal energy output otherwise it is stored as
fat.
 Factors affecting energy requirements are age, rate of growth,
body size and gender, activity levels, body composition,
environmental conditions, illness and disease, pregnancy.
 Research using textbooks, how weight can be managed.
Homework.
 Revise this section of work- Nutrients and
energy.
 Answer all questions- page 64.