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:

1. Base your meals on starchy foods2. Eat lots of fruit and vegetables3. Eat more fish4. Cut down on saturated fat and sugar5. Try to eat less salt – no more than 6g a day6. Get active and try to be a healthy weight7. Drink plenty of water8. 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-

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 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?

Functions of protein: Growth of body cells. Maintenance and repair of body cells. To provide a source of energy.

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 fat-soluble 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 circulation, reduces cholesterol and high blood pressure

As above 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:

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 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 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

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 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: 1 2 3

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.