Transcript Energy - manorhousehomeeconomics

ENERGY
© PDST Home Economics.
Energy
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Energy is the ability to do work
The amount of energy the body needs depends on a
variety of factors, including : age, size & body weight,
gender, levels of activity, occupation, climate,
pregnancy, & illness
Measuring Energy

Energy is measured in kilocalories (kcal) or kilojoules
(kJ)
Nutrient
Kcal/kJ
Protein
Carbohydrate
Fat
Alcohol
4kcal/17kJ
4kcal/17kJ
9kcal/37kJ
7kcal/29kJ
Factors affecting energy
requirements
1.
Age
Young people require more energy as they are growing rapidly & tend
to be very active. As people get older energy requirements decrease,
together with their BMR (Basal Metabolic Rate)
2.
Size & Body Weight
The larger the body, the more energy it needs
3.
Gender
Men have a higher proportion of muscle to fat compared to women,
therefore men require more energy
4.
Level of Activity
The more people active are, the more energy they need. Running
requires more energy than playing a computer game
Factors affecting energy
requirements
4.
Occupation
Sedentary work eg. Office work, requires less energy than
manual work eg. Construction cork
5.
Climate
More energy is needed in colder climates to maintain a
consistent body temperature
6.
Pregnancy
During pregnancy & lactation, women require more energy
Pregnancy: Energy needed for the developing foetus
Lactation: Energy needed for the production of breast milk
7.
Illness
During times of illness, different amounts of energy are
Kate Hehir
required, eg, less energy is needed
during convalescence
Role of Energy in the Body
Energy fulfils four main roles in the body
1.
Growth
2.
Physical Activity
3.
Generating Heat
4.
Basal Metabolic Rate
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Role of Energy in the Body cont.....
Growth
Energy is also required for growing by toddlers,
young children, adolescents & pregnant women
1.
2.
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Physical activity
Energy is required for all physical tasks, including
standing, walking and running
The more strenuous the physical activity, the more
energy required
3.
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4.
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Generating heat
To maintain the body temperature at 37˚C, energy is
required
This is known as thermogenesis
Basal Metabolic Rate (BMR)
The minimum amount of energy needed to keep
internal organs working and to maintain body
temperature
Each person’s BMR is determined by their:
- Body weight
- Age
- Gender
BMR is measured when a person is completely at
rest, twelve hours after eating
Energy Balance
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Energy balance is reached when :
energy intake = energy output
If energy intake is greater than energy output, this
means being overweight or obese
If energy intake is less than energy output, this means
being underweight
Empty kilocalories provide energy but do not supply
the body with any nutritional value, e.g. Soft drinks
Daily Energy Requirements Table: Refer to Textbook
Healthy Eating Guidelines
Textbook
Reference

Refer to
the 10
healthy
eating
guidelines
in your
text book
Formulation of Guidelines – How?
1.
2.
3.
Dietary practices of population
are surveyed
The findings are analysed by
nutritional experts
Areas that require attention are
highlighted and considered in
drawing up the list of guidelines
Current Healthy Guidelines
Food Pyramid
Refer to
Diagram in
your text book
Function of Healthy Eating Guidelines
 To improve the nutritional status of the Irish
diet
 To promote an active & energetic lifestyle
 To respond to growing concerns about
childhood & adult obesity
 To recommend a reduction in over-processed
foods
 To recommend an increase in fibre to prevent
disorders of the bowel
 To ensure that all food groups & servings are
met
Reference Terms
RDA: Recommend Dietary Allowance
LTI: Lowest Threshold Intake: the least amount of
nutrient requirements that are needed by the public
Function of RDA’s: RDA’s help to:
1.
Interpret food consumption records
2.
Evaluate the adequacy of food supplies in meeting
national nutritional needs
3.
Design nutritional information labels
4.
Develop new products in industry
5.
Provide nutritional information on labels
Dietary Reference Values (DRV)
Dietary Reference Terms (DRV): RNI, LRNI, EAR
 These comprise a series if estimates of the amount
of energy & nutrients needed by different groups of
people
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RNI: Reference nutrient intake
LRNI: Lower reference nutrient intake
EAR: Estimated average requirements
Food Composition Tables: Show the nutrient content of
different foods per 100g or of liquid & they also show
the energy value of foods. Refer to textbook to view
Tables
Dietary Requirements of Babies
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First 6 months babies are fed milk
Either breast milk or formulated milk – Development & growth
Breast milk contains all the nutrients a baby needs & is recognised as
being the best for babies
Advantages of Breast feeding
 Contains antibodies that build up the baby’s resistance to diseases
 Correct temperature
 No need to prepare bottles or buy formula, which saves on time &
eliminates cost
 Sterile
 Promotes bonding between mother & child
 Babies are likely to gain the correct amount of weight
 Easier to lose excess baby weight
Reasons for not Breast feeding:
1. HIV positive2. Use of illegal drugs 3. Use of prescribed drugs
Weaning
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Solid foods are introduced when the baby is between 4 & 6
months
Single-ingredient foods should be used(this gives time to notice
any reaction – allergies/intolerances
Infant cereals, pureed fruit & vegetables are the first foods
given to babies
Factors to consider when weaning
 No sugar or salt should be added
 A balanced of foods from the four major food groups is
recommended
 Never give babies tea or coffee
 Honey should also be avoided until the baby is one year old
 Avoid additives by using fresh homemade food
Dietary Requirements of Children
Children need a highly nutritious diet as they continue to grow &
develop
 Protein: This promotes growth & is found in meat, eggs & cheese
 Calcium & vitamin D: These help develop teeth & bones & are
found in dairy products, particularly milk & cheese
 Iron & Vitamin C: These promote general health & foods such as
meat & dark green vegetables are rich in these nutrients
 Energy: Children who are active need a high intake of energy foods
 Sugary sweets & snacks should be avoided in order to reduce the
risk of obesity & tooth decay
 Portion sizes should be relative, i.e. For a child small portion sizes
are key. It is also important that food is arranged attractively as
children, like adults, ‘eat with their eyes’
 Lunches should be well balanced, e.g. Sandwiches should have varied
fillings. Fruit & yoghurt should be included with a healthy drink
Dietary Requirements of
Adolescents
Adolescence is a time of continual development & change
 Protein: Needed for growth & is found in meat & fish
 Calcium & vitamin D: For healthy teeth & bones. Found in
milk & cheese
 Iron: Important for teenage girls as they begin
menstruation, which leads to a loss of iron from the body;
this in turn can lead to anaemia. They must, therefore,
ensure they include iron-rich foods in their diet. Eg. Red
meat & offal
 Vitamin C: Increases the absorption of iron. It is also an
important factor in the diet of teenagers, girls in particular.
Vitamin C is found in fresh fruit and vegetables
 Energy requirements depend on the teenager’s level of
activity. Very active teenagers require high-energy foods
 High fibre foods are a good alternative to sugary foods
Problems associated with eating
patterns of adolescents
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Eating disorders, such as anorexia nervosa & bulimia
nervosa
Missing meals
Eating a large amount of fast food & snacks
‘Faddy’ eating
High energy intake through snacks, etc. But low intake
of nutrients
Start of alcohol consumption
Poor diet can contribute to problems such as acne &
obesity
Dietary Requirements of Adults
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Protein: - repair the body’s cells, found in meat, fish & eggs
Fat: Polyunsaturated fats reduce the risks of coronary heart
disease e.g. oily fish
Carbohydrates: - provide energy. Reduce refined carbohydrate
& replace them with high-fibre foods, e.g. Wholegrain bread
Vitamins: Vitamin B for the release of energy from food. Vitamin
C for the absorption of iron. Vitamin D for the absorption of
calcium (oily fish, milk)
Minerals: Iron for healthy blood & to prevent anaemia; calcium
for strong bones & healthy teeth (milk & cheese)
Water: Water is important to remain hydrated
Dietary Requirements of Adults
Special Considerations
 Smoking & alcohol both inrease the risk of CHD
 Reduce salt intake to prevent high blood pressure
Dietary Requirements of Elderly
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Protein: repair of body cells, found in eggs, fish
Fat: Provides energy. To maintain low cholesterol & to reduce the risk
of coronary heart disease eat unsaturated fats e.g. Oily fish,
polyunsaturated butter
Carbohydrates: Necessary for energy. Choose fibre rich e.g.
wholegrain cereals, fruits & vegetables
Vitamins: Vitamin C(fruit & vegetables) for iron absorption & the
healing of wounds. Vitamin A(liver, eggs, carrots) for healthy eyes &
skin. Vitamin D(milk, yoghurt) for the absorption of calcium
Minerals: Calcium(milk, cheese) for strong bones. Iron(offal, dark
green vegetables) to prevent anaemia
Water: This is necessary to remain hydrated
Dietary Requirements of Elderly
Special Considerations
 Sugar intake should be reduced to prevent diabetes
 Salt intake should be reduced to prevent high blood
pressure
 Spicy foods should be avoided to prevent indigestion
 Choose foods that are easily digestible, e.g. white
fish, eggs & milk.
Dietary requirements of convalescents
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Protein: Repair of body cells e.g. eggs, fish
Fat: Reduce saturated fat & replace with polyunsaturated fat
e.g vegetable oils
Carbohydrates: Reduce as not using much energy Eat high fibre
foods to prevent constipation e.g. prunes
Vitamins: Vitamin A in oily fish and liver good for healthy skin
and respiratory tract.
Minerals (Calcium & iron): These are important to promote
recovery, e.g. To heal wounds & prevent anaemia. Milk, cheese,
eggs, offal & dark green vegetables should be included
Water: This is important to maintain hydration, as dehydration
during an illness is very common
Dietary requirements of convalescents
Special Considerations
 Small portions that are easy to eat are preferable
 Meals prepared in a hygienic environment (because of
an increased susceptibility) to illness
 Foods that are easy digestible, such as white fish,
eggs & milk, should constitute a sizeable portion of food
intake
Pregnant & Breast feeding Women
Protein: growth of new body cells
 Fat: Essential fatty acids (oily fish, eggs, liver) are necessary for
a foetus’s nervous system
 Carbohydrate: necessary for energy, choose high fibre sources
to prevent constipation e.g. wholemeal bread, pasta, fruit & veg.
 Vitamins: Vitamin B folic acid (fortified cereals, leafy green
vegetables) necessary to prevent neural tube defects, such as
spina bifida, in foetuses. Vitamin C- absorption of iron. Vitamin
D- absorption of calcium
 Minerals: Calcium (dairy products) for strong bones & healthy
teeth. Iron for healthy blood & prevent anaemia in both mother
& baby
 Water: necessary for hydration
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Pregnant & Breast feeding Women
Special Considerations
 Extra energy is needed during pregnancy, about 200
kcals
 Salt intake should be reduced to prevent high blood
pressure & water retention (odema)
 Do not smoke- low birth weight
 No Alcohol- can cause foetal alcohol syndrome
 Pregnant women should not eat raw eggs, cooked
chilled foods, soft cheese, shellfish, etc. To
prevent the risk of food poisoning, such as salmonella
& listeria. Can lead to miscarriage