Food and DietFood and Diet

NutrientsNutrients

NutrientsNutrientsCarbohydrates

Fats

Proteins

Vitamins

Minerals

Water

Composition of CarbohydratesComposition of Carbohydrates

Come from Come from plant foodsplant foods

CheapestCheapest and most and most plentifulplentiful of of all nutrientsall nutrients

Foods which contain Foods which contain carbohydrates, are called carbohydrates, are called energy energy foodsfoods

All of the energy obtained from All of the energy obtained from food starts with a single sugar unit food starts with a single sugar unit - - glucoseglucose. Some plants store . Some plants store energy for later use by combining energy for later use by combining sugars to make sugars to make starchstarch. .

Classification of CarbohydratesClassification of Carbohydrates

SugarSugar

StarchStarch

CelluloseCellulose

PectinPectin

Carbohydrates - SugarCarbohydrates - Sugar

Sugars Sugars areare found in found in honey, fruit (both honey, fruit (both fresh and dried) soft fresh and dried) soft drinks, milk and drinks, milk and sugar. sugar.

Carbohydrates - StarchCarbohydrates - Starch

Starches Starches areare found in cereals, found in cereals, pasta, flour, bread, pasta, flour, bread, potatoes, root and potatoes, root and pulse vegetables. pulse vegetables.

Carbohydrates – Cellulose / FibreCarbohydrates – Cellulose / Fibre

Cellulose or Dietary Fibre Cellulose or Dietary Fibre isis found found inin whole cerealswhole cereals wholemeal breadwholemeal bread outer skins of fruit and vegetablesouter skins of fruit and vegetables brown ricebrown rice OatmealOatmeal

In In refinedrefined foods the dietary fibre is foods the dietary fibre is removed during processing e.g. removed during processing e.g. wholemeal flour contains fibre but wholemeal flour contains fibre but white flour does not. white flour does not.

Carbohydrates - PectinCarbohydrates - Pectin

Pectin is found in Pectin is found in ripe fruitripe fruit

Functions of CarbohydratesFunctions of CarbohydratesCarbohydrates provides the body with Carbohydrates provides the body with heat and energyheat and energy

Fibre helps the movement of food through Fibre helps the movement of food through the intestine.the intestine.

Fibre rich and starchy foods provide a "full Fibre rich and starchy foods provide a "full feeling“feeling“

Pectin helps jam to setPectin helps jam to set

RDARDA

Nutritionists believe that the amount of Nutritionists believe that the amount of sugarsugar eaten in the western countries eaten in the western countries needs to be needs to be decreaseddecreased and the amount of and the amount of fibrefibre needs to be needs to be increasedincreased. .

The Recommended Dietary Allowance The Recommended Dietary Allowance (RDA) of fibre is now (RDA) of fibre is now 30g30g per day. We in per day. We in the western world eat about half the the western world eat about half the recommended amount-recommended amount-15g15g per day. per day.

FatsFats

Fat is an important Fat is an important nutrient because it nutrient because it gives us energygives us energy

The body stores The body stores energy as a layer of energy as a layer of fat under the skin. fat under the skin. This is called This is called adipose adipose tissuetissue

Composition of FatsComposition of FatsFats are made from Fats are made from glycerol and glycerol and fatty acidsfatty acidsEach glycerol is attached Each glycerol is attached to three fatty acidsto three fatty acidsGlycerol and fatty acids Glycerol and fatty acids contain the elements contain the elements carbon, hydrogen, and carbon, hydrogen, and oxygenoxygenFats contain a lot of Fats contain a lot of carbon. This is why they carbon. This is why they give us so much energy.give us so much energy.1 gram of fat gives us 9 1 gram of fat gives us 9 kilocalorieskilocalories

Classification of FatsClassification of FatsFats are classified into two Fats are classified into two

groups:groups:Saturated FatsSaturated Fatscome mainly from an animal come mainly from an animal source such as meat, eggs, source such as meat, eggs, milk and dairy produce e.g. milk and dairy produce e.g. cream and butter. There is a cream and butter. There is a lot of saturated fat in butter lot of saturated fat in butter and lard and lard

Unsaturated FatsUnsaturated Fatscome mainly from plant and come mainly from plant and fish sources such as peas, fish sources such as peas, beans and lentils, whole beans and lentils, whole cereals, nuts, cooking oil, cereals, nuts, cooking oil, polyunsaturated margarine polyunsaturated margarine and oily fish and oily fish

Functions of FatsFunctions of Fats Fat insulates the body. A layer of fat Fat insulates the body. A layer of fat under the skin prevents heat loss from the under the skin prevents heat loss from the body. body.

   Fat protects the delicate organs such as Fat protects the delicate organs such as the kidneys and nerves. A layer of fat the kidneys and nerves. A layer of fat surrounds them. surrounds them.

   Fats provide the body with heat and Fats provide the body with heat and energy. This helps to keep the body at the energy. This helps to keep the body at the correct temperature (37o C). correct temperature (37o C).

   Fat is a source of the fat-soluble vitaminsFat is a source of the fat-soluble vitamins

RDA of FatsRDA of Fats

It is recommended that we eat 50% It is recommended that we eat 50% saturated fat and 50% unsaturated fat in saturated fat and 50% unsaturated fat in our dietour diet

People in the western world eat too much People in the western world eat too much saturated fat and it is recommended that saturated fat and it is recommended that we cut down on our intakewe cut down on our intake

We should also increase our intake of We should also increase our intake of unsaturated fats unsaturated fats

To cut down on Saturated FatsTo cut down on Saturated Fats

Grill rather than fry.Grill rather than fry.

Use vegetable oil instead of hard fats for Use vegetable oil instead of hard fats for frying.frying.

Remove visible fat from meat.Remove visible fat from meat.

Look for hidden fats in the diet e.g. pastries Look for hidden fats in the diet e.g. pastries and crisps.and crisps.

Use low fat milk, cheese, yoghurt and Use low fat milk, cheese, yoghurt and mayonnaisemayonnaise

ProteinProtein

Our bodies are made up of billions of cells, Our bodies are made up of billions of cells, which contain proteinwhich contain protein

Throughout our lives cells wear out and Throughout our lives cells wear out and are replacedare replaced

All the material for new cells comes from All the material for new cells comes from foodfood

The main nutrient involved in the building The main nutrient involved in the building of new cells and replacing of worn cells is of new cells and replacing of worn cells is protein protein

Composition of ProteinsComposition of Proteins

Proteins are made up of small units called Proteins are made up of small units called amino acidsamino acids

The amino acids, which the body cannot The amino acids, which the body cannot make, are known as essential amino acidsmake, are known as essential amino acids

Adults need 8 and children need 10 Adults need 8 and children need 10 essential amino acids. essential amino acids.

Composition of ProteinsComposition of Proteins

Proteins are broken down Proteins are broken down into amino acids in the into amino acids in the digestive systemdigestive systemAmino acids Amino acids are smallest are smallest units of Protein. They can units of Protein. They can then be used to build up then be used to build up different proteins for the different proteins for the formation of new cells in formation of new cells in the bodythe bodyAmino acids are made up Amino acids are made up of the elements carbon, of the elements carbon, hydrogen, oxygen and hydrogen, oxygen and nitrogen nitrogen

Classification of ProteinsClassification of Proteins

Classified into two groups: Classified into two groups: HBV and LBVHBV and LBV

High Biological Value Proteins High Biological Value Proteins come mainly from come mainly from animal animal foodsfoods such as meat, fish, such as meat, fish, eggs, cheese and milkeggs, cheese and milk

Low Biological Value Proteins Low Biological Value Proteins come mainly from come mainly from plant foodsplant foods such as peas, beans and such as peas, beans and lentils, whole cereals and nuts. lentils, whole cereals and nuts. These foods also contain fibre These foods also contain fibre and are low in fat and are low in fat

Functions of ProteinsFunctions of Proteins

The functions of proteins are:The functions of proteins are:

  Growth of new cells such as skin hair and Growth of new cells such as skin hair and blood.blood.

   Repair of damaged cells.Repair of damaged cells.

   Production of heat and energy.Production of heat and energy.

Manufacture of important body chemicals Manufacture of important body chemicals such as enzymes, hormones and such as enzymes, hormones and antibodies. antibodies.

RDA of ProteinsRDA of Proteins

The RDA of protein The RDA of protein depends on your depends on your body weightbody weight

For every kilogram of For every kilogram of body weight one gram body weight one gram of protein per day is of protein per day is needed, e.g. if you needed, e.g. if you weigh 60 kg you need weigh 60 kg you need 60 g of protein per 60 g of protein per dayday

VitaminsVitaminsThe word "vitamin" comes from vita, the The word "vitamin" comes from vita, the Latin for "life“Latin for "life“Everybody must eat a certain amount of Everybody must eat a certain amount of vitamins to stay healthyvitamins to stay healthyVitamins are chemicals found in very small Vitamins are chemicals found in very small amounts in many different foods. Tiny amounts in many different foods. Tiny quantities are enough for the needs of the quantities are enough for the needs of the bodybodyIf people live on a very limited range of If people live on a very limited range of foods they may not get their proper share foods they may not get their proper share of vitamins of vitamins

Classification of VitaminsClassification of VitaminsVitamins, of which there Vitamins, of which there are 14, are classified are 14, are classified into two main groups: into two main groups: WaterWater soluble and soluble and FatFat solublesoluble

Fat solubleFat soluble – stored in – stored in bodies fat tissuebodies fat tissue A, D, E & KA, D, E & K

Water solubleWater soluble – not – not stored in the bodystored in the body B vitamins, folic acid & B vitamins, folic acid &

vitamin Cvitamin C

VitaminsVitamins

Fat soluble:Fat soluble: Vitamin AVitamin A - needed for healthy - needed for healthy

vision, bone growth, vision, bone growth, reproduction and the immune reproduction and the immune systemsystem

found in dark green, orange and found in dark green, orange and yellow vegetables, such as yellow vegetables, such as spinach, carrots, broccoli, mangos, spinach, carrots, broccoli, mangos, apricots, vegetable soup and apricots, vegetable soup and tomato juice.tomato juice.It is also found in meat and dairy It is also found in meat and dairy products such as liver, beef, products such as liver, beef, chicken, whole milk and eggs. chicken, whole milk and eggs.

VitaminsVitamins

Fat soluble:Fat soluble: Vitamin D - Vitamin D - controls the absorption of controls the absorption of

calcium and phosphorus, which are calcium and phosphorus, which are essential for bone growth and essential for bone growth and developmentdevelopment

sardines and tuna, liver, egg yolks, some sardines and tuna, liver, egg yolks, some breakfast cereals and vitamin D-fortified breakfast cereals and vitamin D-fortified milk. Vitamin D can also be made when milk. Vitamin D can also be made when the skin is exposed to sunlight the skin is exposed to sunlight

VitaminsVitaminsWater solubleWater soluble::

Vitamin C -Vitamin C - helps to helps to maintain skin integrity, maintain skin integrity, absorb iron from the gut absorb iron from the gut and heal wounds, and is and heal wounds, and is important in immune important in immune functions functions

Vitamin C is found in citrus Vitamin C is found in citrus fruit and juices, tomatoes, fruit and juices, tomatoes, spinach, potatoes, berries, spinach, potatoes, berries, green and red peppers, green and red peppers, and broccoliand broccoli

VitaminsVitamins

Water soluble:Water soluble:

Folate (folic acid), also called vitamin B9 is Folate (folic acid), also called vitamin B9 is essential for the normal formation of the essential for the normal formation of the red blood cells, protein metabolism, red blood cells, protein metabolism, growth and cell division growth and cell division

Food sources include liver, citrus juices Food sources include liver, citrus juices and fruits, beans, nuts, seeds, liver, dark and fruits, beans, nuts, seeds, liver, dark green leafy vegetables. green leafy vegetables.

MineralsMinerals

The human body requires about 20 mineral The human body requires about 20 mineral elementselementsEach has a specific function and is found in Each has a specific function and is found in certain foodscertain foodsA good varied diet should supply all essential A good varied diet should supply all essential mineralsmineralsSome minerals are described as Some minerals are described as trace elements trace elements because the are required in smaller amountsbecause the are required in smaller amountsMinerals are lost into the water during cooking Minerals are lost into the water during cooking

MacromineralsMacrominerals

Calcium - for muscle and digestive system health, Calcium - for muscle and digestive system health, builds bone, neutralizes acidity, clears toxins, helps builds bone, neutralizes acidity, clears toxins, helps blood streamblood stream Found in milk, cheese, green leafy vegetables Found in milk, cheese, green leafy vegetables

Potassium – for growth of lean tissuePotassium – for growth of lean tissue Found in bananasFound in bananas

Sodium – regulation of water balance in the bloodSodium – regulation of water balance in the blood Found in table salt, bacon, snack foodsFound in table salt, bacon, snack foods

Sulfur Sulfur

MagnesiumMagnesium

PhosphorusPhosphorus

Trace MineralsTrace MineralsIodine – Needed for the fIodine – Needed for the formation of thyroxine, ormation of thyroxine, a hormone in the thyroid gland which controls a hormone in the thyroid gland which controls metabolismmetabolism Found in vegetables and sea fish Found in vegetables and sea fish

Iron – Needed to make red blood cellsIron – Needed to make red blood cells Found in red meat, liver & cabbageFound in red meat, liver & cabbage

Manganese – Processing of oxygenManganese – Processing of oxygen

ZincZinc

CobaltCobalt

CopperCopper

WaterWaterWater is absolutely Water is absolutely essential to life. Over essential to life. Over 70% of the human body 70% of the human body is made up of water. It is is made up of water. It is found in:found in: MusclesMuscles SalivaSaliva BloodBlood Digestive JuicesDigestive Juices MucusMucus SweatSweat

Composition of WaterComposition of Water

Water contains the elements hydrogen Water contains the elements hydrogen and oxygenand oxygen

They are present in the ratio 2:1, two parts They are present in the ratio 2:1, two parts hydrogen to one part oxygenhydrogen to one part oxygen

Pure water freezes at 0C and boils at Pure water freezes at 0C and boils at 100C 100C

Sources of WaterSources of WaterThe main sources of water are The main sources of water are drinking water and beverages drinking water and beverages like tea, coffee and alcoholic like tea, coffee and alcoholic drinksdrinksWater is also present in many Water is also present in many other foods like meat and fishother foods like meat and fishFruits and green vegetables are Fruits and green vegetables are high in water. Almost all foods high in water. Almost all foods contain water, except those with contain water, except those with a high fat content (butter), and a high fat content (butter), and dry foods (sugar and flour) dry foods (sugar and flour)

Functions of WaterFunctions of Water

It is the chief component of all body fluids.It is the chief component of all body fluids.

It helps dissolve foods and aids digestion.It helps dissolve foods and aids digestion.

It helps remove waste material from the body.It helps remove waste material from the body.

It regulates body temperature by perspiration.It regulates body temperature by perspiration.

It is a source of dissolved minerals such as It is a source of dissolved minerals such as flourine and calcium. flourine and calcium.

It keeps the body fluids liquid so that they may It keeps the body fluids liquid so that they may flow easily. flow easily.

RDA of WaterRDA of Water

As 2-2.5 litres of water As 2-2.5 litres of water are lost daily by are lost daily by excretion, and excretion, and perspiration, an equal perspiration, an equal amount is required daily amount is required daily by the body to avoid by the body to avoid dehydrationdehydration

1.5 litres of water is 1.5 litres of water is obtained from beverages obtained from beverages and 0.8 from food.and 0.8 from food.