NUTRITIONNUTRITION

The study of food, its composition, the The study of food, its composition, the amounts needed by the body and its amounts needed by the body and its effects on the bodyeffects on the body

© PDST Home Economics

DEFINITIONSDEFINITIONS

Food: Food: any substance, solid or liquid, that contains any substance, solid or liquid, that contains nutrientsnutrients..

Nutrients: Nutrients: substances that can be digested and used substances that can be digested and used by the body. by the body.

Elements: Elements: All nutrients are made up of elements. They All nutrients are made up of elements. They are simple substances that cannot be broken down are simple substances that cannot be broken down into anything simpler.into anything simpler.

Diet: Diet: the selection of food each person eatsthe selection of food each person eats Balanced diet: Balanced diet: contains all the nutrients in the correct contains all the nutrients in the correct

amount for the needs of the body.amount for the needs of the body. RDA:RDA: Recommended dietary allowance Recommended dietary allowance GDA:GDA: Guideline daily amount Guideline daily amount

NutrientsNutrients

There are There are 6 nutrients6 nutrients

ProteinsProteins Fats / LipidsFats / Lipids CarbohydratesCarbohydrates Mineral elementsMineral elements VitaminsVitamins WaterWater

NutrientsNutrients

Macronutrients:Macronutrients: needed in large amounts by needed in large amounts by the body i.e. protein, fat and carbohydrate.the body i.e. protein, fat and carbohydrate.

Micronutrients:Micronutrients: Needed in small amounts by Needed in small amounts by the body i.e. vitamins, mineralsthe body i.e. vitamins, minerals

NutrientsNutrients

CompositionComposition: the elements that make up the : the elements that make up the nutrients.nutrients.

Classification:Classification: dividing things into groups or dividing things into groups or classes.classes.

Sources:Sources: foods that supply a large amount of foods that supply a large amount of a nutrient.a nutrient.

Functions:Functions: Uses of nutrients in the body Uses of nutrients in the body

Protein - CompositionProtein - Composition

Made up of the elements:Made up of the elements: CarbonCarbon HydrogenHydrogen OxygenOxygen NitrogenNitrogen

Protein is the only nutrient with Protein is the only nutrient with nitrogennitrogen which is which is needed for growthneeded for growth

The elements join to form The elements join to form Amino AcidsAmino Acids

The amino acids link together in long chains The amino acids link together in long chains called called Proteins Proteins

Protein - CompositionProtein - Composition

Protein - ClassificationProtein - Classification

There are There are 2 classes2 classes of protein of protein

1. HBV protein (High Biological Value)/ First 1. HBV protein (High Biological Value)/ First class protein / Animal protein.class protein / Animal protein.

2. LBV protein (Low Biological Value ) / 2. LBV protein (Low Biological Value ) / Second class protein / Plant protein.Second class protein / Plant protein.

Both classes of protein are needed in the dietBoth classes of protein are needed in the diet

Protein - SourcesProtein - Sources

Animal protein: meat, poultry, fish, eggs, Animal protein: meat, poultry, fish, eggs, cheese, yoghurt, milk.cheese, yoghurt, milk.

Plant protein: Lentils, Beans, Peas, nuts, Plant protein: Lentils, Beans, Peas, nuts, cerealscereals

Plant protein foods contain: Plant protein foods contain: Less saturated fatLess saturated fat More fibreMore fibre Cheaper to produceCheaper to produce

Protein - SourcesProtein - Sources

Protein - FunctionsProtein - Functions

The The growthgrowth of all body cells of all body cells

For For repairrepair of worn or damaged cells of worn or damaged cells

To make To make hormones, enzymeshormones, enzymes and and antibodiesantibodies in the bodyin the body

Protein - functionsProtein - functions

Protein – RDA and Energy value

RDA for protein is 1g per day per Kg of body RDA for protein is 1g per day per Kg of body weight.weight.

1 gram of protein can release 4 kilocalories 1 gram of protein can release 4 kilocalories or 17 kilojoules of energyor 17 kilojoules of energy

Test on Protein1. Atoms of which elements make up protein?

2. What’s special about Nitrogen?

3. Name the small units that form proteins

4. Name the 2 classes of protein

5. List 5 food sources for each class

6. Give 2 functions for protein

7. What are the effects of protein deficiency

8. Are proteins micro or macro nutrients?

9. How much protein do we need per day?

10. What is the energy value of 1 gram of protein?

Lipids (fats & oils)- Lipids (fats & oils)- CompositionComposition

Lipids are called Lipids are called fatsfats when solid at room when solid at room temperature and temperature and oils oils when they are liquid at room when they are liquid at room temperature.temperature.

Made of Made of 3 elements3 elements:: CarbonCarbon HydrogenHydrogen OxygenOxygen The elements make units called The elements make units called glycerol glycerol and and fatty fatty

acidsacids Each glycerol joins to 3 fatty acids to form a Each glycerol joins to 3 fatty acids to form a lipidlipid

Lipids - structureLipids - structure

Lipids - ClassificationLipids - Classification

There are 2 classes of lipidsThere are 2 classes of lipids

1. 1. SaturatedSaturated lipids: animal fats, solid at room lipids: animal fats, solid at room temperature.temperature.

2.2.UnsaturatedUnsaturated lipids: plant and fish oils, liquid lipids: plant and fish oils, liquid at room temperatureat room temperature

Lipids - SourcesLipids - Sources

1. Saturated fats are found in: butter, suet, 1. Saturated fats are found in: butter, suet, lard, meat, cheese, eggs, milk, yoghurt.lard, meat, cheese, eggs, milk, yoghurt.

2. Unsaturated fats are found in: fish, nuts, 2. Unsaturated fats are found in: fish, nuts, seeds, cereals, soya beans, olives, avocado seeds, cereals, soya beans, olives, avocado pears, some margarines, cooking oils.pears, some margarines, cooking oils.

Saturated fat Saturated fat sourcessources

Unsaturated fat sourcesUnsaturated fat sources

Lipids - FunctionLipids - Function

Releases heat and energy for the bodyReleases heat and energy for the body

Insulates the bodyInsulates the body

Protects delicate organs e.g. kidneysProtects delicate organs e.g. kidneys

Source of fat soluble vitamins A, D, E, KSource of fat soluble vitamins A, D, E, K

Delays hungerDelays hunger

Adds flavour to foodsAdds flavour to foods

Functions of Functions of fatfat

Overeating LipidsOvereating Lipids

Overweight or obesityOverweight or obesity

Saturated fats raise blood cholesterol. This Saturated fats raise blood cholesterol. This causes high blood pressure, strokes and causes high blood pressure, strokes and heart diseaseheart disease

Benefits of saturated Benefits of saturated lipidslipids

Help reduce cholesterolHelp reduce cholesterol

Omega 3 and omega 6 fatty acids reduce risk Omega 3 and omega 6 fatty acids reduce risk of heart disease and improve brain function. of heart disease and improve brain function. They are found in oily fish, seeds and nutsThey are found in oily fish, seeds and nuts

Carbohydrates - Carbohydrates - CompositionComposition

Made of 3 elements:Made of 3 elements:

Carbon Carbon Hydrogen Hydrogen OxygenOxygen

The elements form single sugar units e.g. The elements form single sugar units e.g. glucoseglucose

The sugar units link up to form other The sugar units link up to form other carbohydratescarbohydrates

Carbohydrates-ClassificationCarbohydrates-Classification

There are There are 3 classes3 classes of carbohydrates of carbohydrates

SugarsSugars

StarchesStarches

Cellulose (fibre, roughage)Cellulose (fibre, roughage)

Carbohydrates - SourcesCarbohydrates - Sources

1. Sugars are found in: 1. Sugars are found in: fruitfruit, , honeyhoney, table , table sugar, cakes, biscuits, sweets, fizzy drinks, sugar, cakes, biscuits, sweets, fizzy drinks, jamjam

2. Starches are found in: bread, potato, 2. Starches are found in: bread, potato, pasta, ricepasta, rice

3. Cellulose is found in: Fruit, vegetables, 3. Cellulose is found in: Fruit, vegetables, whole-cereals, seeds, nuts, beans, brown whole-cereals, seeds, nuts, beans, brown bread, brown rice, high fibre breakfast bread, brown rice, high fibre breakfast cerealscereals

Carbohydrate - Carbohydrate - sourcessources

Carbohydrate - functionsCarbohydrate - functions

To supply the body with energyTo supply the body with energy

Extra carbohydrate is changed to body fat Extra carbohydrate is changed to body fat and stored and stored

Cellulose is needed to keep the digestive Cellulose is needed to keep the digestive system healthy and lower cholesterolsystem healthy and lower cholesterol

CelluloseCellulose

Not digested, just passes through our Not digested, just passes through our digestive system unchangeddigestive system unchanged

Helps to push food through the intestine and Helps to push food through the intestine and prevent constipation, diverticulosis and prevent constipation, diverticulosis and cancer of the coloncancer of the colon

We need to eat 30g of fibre a day to be We need to eat 30g of fibre a day to be healthy most people only eat 15ghealthy most people only eat 15g

SugarSugar

Sugar is a food we need to eat less ofSugar is a food we need to eat less of

Too much sugar is causing obesity, tooth Too much sugar is causing obesity, tooth decay and diabetesdecay and diabetes

A lot of sugar is hidden in foods that don’t A lot of sugar is hidden in foods that don’t really taste sweet especially convenience really taste sweet especially convenience foods e.g. spaghetti hoops, check label for foods e.g. spaghetti hoops, check label for ingredientsingredients

Reducing Sugar in your Reducing Sugar in your Diet.Diet.

Replace sugary snacks with healthy fruit , Replace sugary snacks with healthy fruit , nuts, yoghurt etc.nuts, yoghurt etc.

Drink water instead of fizzy drinksDrink water instead of fizzy drinks

Sweeten breakfast cereals with fresh or dried Sweeten breakfast cereals with fresh or dried fruit e.g. raisins, bananafruit e.g. raisins, banana

Check sugar content on food labels and Check sugar content on food labels and choose low sugar foods choose low sugar foods

Vitamins – Vitamins – (micronutrients)(micronutrients)

Essential for good healthEssential for good health

Each vitamin has its own job to do in the Each vitamin has its own job to do in the bodybody

If a vitamin is missing from the diet a If a vitamin is missing from the diet a deficiency disease can occurdeficiency disease can occur

Vitamins - ClassificationVitamins - Classification

1. 1. Fat –Soluble Fat –Soluble (dissolve in fat) Vitamins: A,D,E,K.(dissolve in fat) Vitamins: A,D,E,K. 2. 2. Water – Soluble Water – Soluble (dissolve in water) Vitamins:B, C(dissolve in water) Vitamins:B, C

If more of the fat soluble vitamins is eaten than the If more of the fat soluble vitamins is eaten than the body needs it is stored in the liver.body needs it is stored in the liver.

If an overdose of these vitamins is eaten it causes If an overdose of these vitamins is eaten it causes hypervitaminosishypervitaminosis which is harmful to the body. which is harmful to the body.

Water soluble vitamins are not stored in the body, if Water soluble vitamins are not stored in the body, if too much is eaten they are removed in the urine.too much is eaten they are removed in the urine.

It is therefore important to eat water soluble It is therefore important to eat water soluble vitamins every dayvitamins every day

Fat soluble vitaminsFat soluble vitaminsVitaminVitamin SourcesSources FunctionsFunctions DeficiencyDeficiency

AA

CaroteneCarotene

(changed to vitamin A(changed to vitamin A

in the body)in the body)

Oily fish, cod liver oilsOily fish, cod liver oils

liver/kidneyliver/kidney

eggs, margarineeggs, margarine

e.g. cabbage, spinache.g. cabbage, spinach

EyesightEyesight

GrowthGrowth

Membranes/liningsMembranes/linings

of the bodyof the body

Retarded growthRetarded growth

Night blindnessNight blindness

Unhealthy membranes /liningsUnhealthy membranes /linings

DD Sunlight oily fish, cod liver oil, tinned salmon/sardines,Sunlight oily fish, cod liver oil, tinned salmon/sardines,

margarine, butter eggs, margarine, butter eggs, Healthy bones and teethHealthy bones and teeth

RicketsRickets

Tooth decayTooth decay

Osteoporosis Osteoporosis

Water Soluble VitaminsWater Soluble Vitamins

Vitamin

Sources FunctionDeficiencies

B group

Folic acid

Meat, fish, eggs, cereals, flour, yeast, nuts,

pulses, Brown bread, supplements

Controls release of energy from food.

For a healthy nervous system

For growth of healthy foetus during pregnancy

Retarded growth

Tiredness

Beriberi

Pellagra

Neural tube diseases

C

Fruit, esp. blackcurrants, citrus fruit

e.g. oranges, strawberries. Veg. esp.

tomatoes, greens

Healthy skin & gum

Antioxidant

Fights infection

Strengthens blood vessels

Aids healing

Scurvy

Delayed healing

Test on Vitamins

1. Are vitamins micro or macro nutrients?2. What are the two classes of vitamins and name the

vitamins in each class3. List (a) 3 sources of vitamin A (b) 2 sources of

carotene4. What is the functions of vitamin D?5. What happens if you are deficient in Vitamin B?6. List 4 functions for vitamin C7. What vitamin can be got from sunshine?8. Which vitamin prevents scurvy?9. What is hyper-vitaminosis?10. Which vitamin works with calcium in the body?