Download Essential Nutrition and Healthy Eating Revision

Food Technology
Revision 1
Healthy Eating, Eatwell Plate &
Macronutrients
Eating for Health
Our Diet
It is important to choose a variety of foods to ensure that we
obtain the range of nutrients, i.e. proteins, carbohydrates, fats,
vitamins and minerals, which we need to stay healthy
There are guidelines about the amount of nutrients needed by
different people. These include dietary reference value
(DRV), estimates average requirements (EAR) and
reference nutrient intake (RNI)
Eatwell Plate
The Eatwell Plate shows the types & proportions of the main food
groups that are needed for a healthy balanced diet.
On the plate you can see how much of your food should come from
each group. Fruit & vegetables should make up about one third of
the total food per day we eat. A portion is one piece of fruit (apple) or
handful of berries (raspberries)
You do not need to get the balance right every meal, but need to try
to get the balance over a day or each week.
Foods & drinks high in fat and/or sugar aren’t essential to a healthy
diet and shouldn’t be eaten often.
The Eatwell Plate proportions have just changed (April2016) and we
are now advised to eat more than one third fruit and vegetables and
slightly less than a third Carbohydtrates
Eatwell Plate
It is suitable for all except
• Children under the age of two
• People under medical care
• People with special dietary needs
UK Government Healthy Eating Guidelines
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8.
Base your meals on starchy staple foods
Eat lots of fruit & vegetables
Eat more fish, including a portion of oily fish each week
Cut down on saturated fat and sugar
Eat less salt – no more than 6g a day for adults
Get active and maintain a healthy weight
Drink plenty of water
Don’t skip breakfast
5 a day campaign
Encourages us to eat more fruit & vegetables – fresh, frozen,
canned and dried
Recently this has increased to 7 – 10 portions per day
A healthy diet
You should be able to achieve healthy eating by cutting down on
fat (especially saturated), salt and sugars & increasing fibre
(non-starch polysaccharide or NSP)
To help consumers do this, many manufacturers have
voluntarily adopted a system of traffic light labelling:
• Red = amount is high – eat occasionally
• Amber = neither high or low amounts
• Green = amount is low – this is a good choice
Some manufacturers use a different system based on Guide
Line Daily Amounts (GDA) These labels show the % of sugar,
salt, fat & calories in each serving of the product
G.D.A.
Traffic Light Labelling
Maintaining a Healthy Weight
By balancing the calories with being physically active, you can
maintain a healthy weight.
If you eat more calories than your body needs, it gets stored as fat,
and you become overweight. To reach a healthy weight you should
follow a calorie control diet.
If your weight increases to a point where it seriously endangers your
health, you may eventually become obese.
Being overweight or obese increases the risk of developing
• Coronary heart disease (CHD)
• Some cancers
• Type 2 diabetes
• High blood pressure, which can lead to strokes
• Osteoarthritis
Being seriously underweight can also lead to health problems
Quick Test!
1. Which people should check with their GP whether the
Eatwell plate applies to them?
2. Obesity can increase the risk of developing coronary heart
disease – True or False?
3. How can you maintain a healthy weight?
4. What foods should you cut down on to achieve a healthy
diet?
5. Using the traffic light labelling system, a green light means
that the food is a good choice to make – True or False?
Key Words
Make sure you understand these words
Dietary Reference Values
Obesity
Guide Line Daily Amounts
Healthy weight
Eatwell Plate
Healthy diet
Traffic Light Labelling
Healthy Options
Manufacturers recognise that many consumers are concerned
about healthy eating.
They are producing “healthy option foods”. These foods make
claims about
• Low fat
• Low salt
• Low sugar
• High NSP content
We need to know what this actually means
Nutrient
Definitions
Content per
100g
Effects of Excess
Low salt
Less than 0.3g
Salt
High salt
1.5g or more
High blood pressure
Coronary heart
disease
Fat
Low fat
Less than 3g
High Fat
More than 20g
Saturated Low saturated fat
fat
High saturated fat
Sugar
Less than 1.5g
More than 1.5g
Low sugar
Less than 5g
High sugar
More than 15g
Overweight
Obesity
Raised cholesterol
CHD
Overweight
Obesity
Dental decay
Fortification
Some foods are sold with the claim “fortified” – this is the
addition of nutrients to the food
Some foods must have some nutrients added in by law – e.g.
bread must have min amounts of calcium, iron & vitamins;
margarine must contain vitamins A & D
Other foods such as breakfast cereal do this as a “selling point”
Nutrients
Nutrients are divided into 2 categories
Macronutrients
Which are Protein, Carbohydrate & Fat – the body needs
larger amounts of these
Micronutrients
Which are vitamins and minerals – the body needs smaller
amounts BUT a wide variety
Nutrients are substances found in foods. All foods contain a
mix of nutrients
The body also requires water (found in drinks & food) and fibre
found in plant food
Protein
Needed for growth & repair – excess stored as fat
During digestion proteins are broken up into amino acids.
These are absorbed into the bloodstream & made into new
proteins in the body. 20 different amino acids are found in plant
& animal proteins. Thousands of amino acids may be joined
together to make one type of protein.
The body can make 11 of the amino acids from other amino
acids. The remaining 9 amino acids have to be obtained from
protein in the food we eat – these are known as essential amino
acids
Essential amino acids are found in protein from animal tissue
and from soya bean & quinoa – these foods have High
Biological Value (HBV)
Protein from plant sources (other than soya & quinoa) have
Low Biological Value (LBV)
The body needs a variety of both HBV & LBV
Sources of HBV
Sources of LBV
Milk & milk based products (cheese)
Quorn
Eggs
Nuts
Meat
Pulses (peas, beans & lentils)
Shellfish
Rice
Fish (3 portions per week)
Cereals (oat, wheat)
Soya bean & soya bean products
(tofu)
Peanuts
Quinoa
Alternative Proteins
May be eaten as a substitute for animal protein by• People who do not want to eat food from an animal source because of
moral, religious or ethical reasons
• People who are health conscious
• People who want a more varied diet
TVP – textured vegetable protein (made from soya bean)
Quorn – a mycoprotein related to the mushroom
Tivall – made from wheat & vegetable protein, similar texture to meat
Tofu & Bean Curd – made from soya beans
Nutritive Value – high in protein, low in fat, enriched with vitamins &
minerals
Properties – versatile, can be cooked in different ways, bland, colourless,
easy to store & usually cheaper
Quick Test
1. State three functions of protein in the diet
2. State the meaning of the term “essential amino acids”
3. Give the name of one vegetable protein that provides all the
essential amino acids
4. State two products that would give a vegan all the essential
amino acids
5. State one different source of protein for each of the following
target groups (a) toddler (b) lacto-vegetarian (c) elderly person
Key Words to remember & understand their meaning
Macronutrient
amino acid
HBV
LBV
FATS
Provides the body with energy, keeps it warm, protects vital organs
(kidneys) & contains fat soluble vitamins A & D
Fats are solid at room temperature where oils are liquid. Fat can come
from animal & plants.
All fats are high in calories, fat intake should be no more than 35% of our
energy intake, excess is stored as body fat
Visible fats – seen on meat or as butter etc. Invisible fat appear in ready
meals, biscuits, cakes, burgers etc.
Saturated fats – solid at room temp., mainly from animals – too much leads
to high blood cholesterol, CHD, diabetes & obesity
Polyunsaturated fats are soft & oily at room temp, considered heathier
option
Essential fatty acids (EFAs) – cannot be made by the body.
• Omega 3 found in oily fish, seeds, green leafy veg – helps protect heart
• Omega 6 – veg, fruit, grains, chicken – helps lower blood cholesterol
Functions – frying (chips), enriching (sauces), shortening (pastry),
emulsifying (mayonnaise), colour (pastry), creaming (cakes)
Hydrogenated fat - hydrogen is “bubbled” through some oils to improve
flavour & shelf life – margarine, spreads, used in manufactured cakes,
biscuits etc – is as harmful as saturated fats.
Sources
Plant – fruits (avocado), nuts, pulses & seeds
Animal – meat (& their products –lard, suet), dairy (milk, cheese) & oily fish
Saturated Fats
Unsaturated Fats
Meat pies, sausages, hard cheese,
Oily fish, avocados, nuts, seeds,
coconut & palm oil, butter, ghee, lard, sunflower & corn oil, vegetable oil,
cream
soya beans
Carbohydrates
Provides the body with ENERGY for physical activity (walking) and to
maintain bodily functions (breathing), it also provides us with fibre to
help with digestion and sweetens/flavours our food.
Excess is stored as fat which leads to overweight/obesity
Types of Carbohydrates
STARCH
SUGAR
NSP
Polysaccharides
(complex)
pasta, rice
Monosaccharides
(simple sugars)
honey, fruit
Non starch
polysaccharides
Oats, bananas, beans
Disaccharides
Double sugars (Lactose & Sucrose)
Milk, caster sugar
Sugars provide instant energy. Starches have to be digested
into sugars before energy can be released & therefore convert
to energy more slowly.
Sugar causes tooth decay therefore important to brush teeth
after eating sugary foods
The only function of sugar is energy. It does not contain any
other nutrients
Dietary Fibre - NSP
Dietary fibre is the non-digestible cellulose found in plant foods.
It cannot be digested so it passes straight through the digestive system,
absorbing moisture and providing bulk. We should be eating approx.
18g of fibre every day.
Functions
• It holds water & keeps the faeces soft & bulky
• It helps “push” other foods through the system & to “clean” the
intestine of bacteria
• It helps prevent bowel disorders, including constipation & bowel
cancer
• It can help people control their weight because high fibre foods are
filling
• High fibre diets are linked to lower blood cholesterol
Quick Test
1. Why do marathon runners eat starchy foods?
2. Give three functions of carbohydrates in the diet
3. Name two health conditions which may be caused by an
intake of low dietary fibre
4. List two foods which are a good source of dietary fibre