Dietary Requirements for Different Client Groups

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Transcript Dietary Requirements for Different Client Groups

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Carbohydrates
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Proteins
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Fats
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Minerals
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Vitamins
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Water
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Fibre (Roughage)
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C = carbo
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Basic formula (CH20)n
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H20 = hydrate
All Carbohydrates are converted to glucose and absorbed into the
blood
n = 6 C6 H12 O6
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Glucose – vital fuel:
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CHO have a reciprocal relationship with fat
↑ CHO → ↓ Fat
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Chemically carbohydrates are defined by their number of
saccharide units in their structure
 Monosaccharides
 Disaccharides
 Oligosaccharides
 Polysaccharides
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Originate from plants – CO2 + H2O – Photosynthesis
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Not all carbohydrates are digestible
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1 gram of carbohydrate = 4kcal
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In our diet, starches and sugars are main sources of dietary
carbohydrate
Function of Carbohydrate – supply energy, protein sparing,
prevents ketosis – breakdown fatty acids
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Intrinsic sugars: sugars which are incorporated within intact
plant cell walls; eg. fruit and vegetables
Extrinsic sugars: refined sugars; eg. Fruit juices, honey and milk
Non-milk extrinsic sugars: sugars are present in a free and
readily absorbable state eg. sucrose
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Total carbohydrate intake should provide up to 50% energy
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Non-milk extrinsic sugars should not exceed 11% energy intake
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Starches, intrinsic and milk sugars should contribute to 39%
energy intake
Certain diets promote restricted intake of carbohydrates
 Atkins Diet – low carbohydrate diet
 GI Diet – Encourages foods with low glycaemic index (GI) <60
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Contains carbon, hydrogen, oxygen and nitrogen
Protein regulates and maintains body functions; structural
(skeleton, connective tissues), protective (tears, mucus),
transport (plasma proteins and hormones) and enzymatic
(protein synthesis)
Protein are made up of 20 different amino acids bonded
together in different sequences to form may SPECIFIC proteins
Twenty amino acids are important in nutrition
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All amino acids have an acid group and an amino group
attached to a carbon atom
The rest of the amino acid is represented by R and is different
for every amino acid
The carbon to which the carboxyl is attached is the alphacarbon
Amino acids have 4 different groups around the alpha carbon
resulting in optically active L or D isomers or enantiomers
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Essential (indispensable) Amino Acid
- One that the body is unable to make or can only make in
inadequate quantities
- Need to be consumed from the diet
- 8-10 essential amino acids
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Nonessential (dispensable) Amino Acid
- One that the body can make in large enough quantities (Made
from essential amino acids)
- Not necessary to consume these in the diet
- 10-12 nonessential amino acids
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Essential Amino
Acids
Nonessential
Amino Acids
-Phenylalanine
-Valine
-Threonine
-Tryptophan
-Isoleucine
-Methionine
-Histidine
-Arginine
-Leucine
-Lysine
-Alanine
-Asparagine
-Aspartic
acid
-Cysteine
-Glutamic
acid
-Glutamine
-Glycine
-Proline
-Serine
-Tyrosine
Conditionally
essential Amino
Acids
-Cysteine
-Glutamine
-Tyrosine
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Used in body organs and soft tissues
Enormous functional diversity
 Cell membrane structure and function
 Enzymes
 Hormones and other chemical messengers
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Immune factors (antibodies)
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Fluid Balance
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Transport
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Source of energy
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Structural and Mechanical – Collagen in bone and skin; Keratin
in hair and nails; Motor proteins, which make muscles work
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Enzymes
 Proteins that catalyze (speed up) chemical reactions without
being used up or destroyed in the process
 Anabolic (putting things together) and catabolic (breaking
things down) functions Eg. Digestion – salivary amylase
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Hormones
 Chemical messages that are made in one part of the body but
act on cells in other parts of the body Eg. Insulin, some
reproductive hormones
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Immune Function
Antibodies are proteins that attack
and inactivate bacteria and viruses
that cause infection
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Fluid Balance
Proteins in the blood help to maintain
appropriate fluid levels in the vascular system.
Fluid is forced into tissue spaces by blood
pressure generated by pumping action of
heart.
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Transport substances in the blood
 Lipoproteins (transport lipids)
 Hemoglobin ( transports oxygen and carbon dioxide)
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Transports materials across cell membranes
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Proteins are the last to be used for energy
 Occurs in starvation and low carbohydrate diets
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When the body has excess protein stores, some amino acids are
converted and stored as fat in body
Sources of protein
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Functions include;
 Provide energy
 Efficient storage of energy (adipose tissue)
 Insulation
 Essential nutrients required for; metabolic and physiological
processes, structural and functional integrity of cell
membranes
 Control body temperature
 Physical protection to internal organs
 Transport fat soluble vitamins
 Flavour and mouth feel
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Simplest form – composed of a chain of carbons with hydrogen
atoms attached, methyl group and a carboxylic group
Methyl
group
Acid group
Double
Bond
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High energy component – 9 kcal per gram
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Most important contain 16-18 carbons
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Whether a fat is saturated, monosaturated or polysaturated
depends on the location of the double bond
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Only single bonds
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High melting temperature
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Solid at room temperature
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Chemically stable
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Examples include animal fats and
their products
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Linked with risk of cardiovascular
disease
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Contain one double bond
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Usually liquid at room temperature
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Examples include olive oil, rapeseed
Oil, nuts and seeds
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Most beneficial type of fatty acid
 Lower LDL cholesterol
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Contain 2 or more double bonds
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Liquid at room temperature
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Susceptible to oxidation
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Omega 3 and 6
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Polyunsaturated fatty acids are
needed in brain development
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Processed margarines contain
significant amounts of trans fat
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Same adverse affects as
saturated fatty acids
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Wax like substance
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Produced by the liver
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Belongs to steroid family
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Important to limit dietary
cholesterol
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Cholesterol is essential to life
required for synthesis of bile acids
steroid hormones and vitamin D
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Less than 35% of energy intake should come from fats
 No more than 10% from Saturated fatty acids
 No more than 12% Monounsaturated fatty acids
 No more than 6% N-6 Polyunsaturated fatty acids (PUFA)
 0.2g/day minimum N-3 Polyunsaturated fatty acids (PUFA)
 <2% Trans fats
◦ Certain populations may need higher intakes of n-3
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Reduced fat = at least 25% less fat than the standard product
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Low fat food = <3g fat/100g or 100ml
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Fat free = <0.15g fat/100g or 100ml
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Essential organic substances, they yield no energy, but facilitate
energy-yielding chemical reactions
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Essential nutrients in maintenance of normal health
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Obtained from food because the body can’t make them
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But you need only small amounts (micronutrients) because the
body uses them without breaking them down, unlike what
happens to carbohydrates and other macronutrients
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13 compounds have been classified as vitamins
Vitamins A, D, E, and K, the four fat-soluble vitamins, tend to
accumulate in the body
Vitamin C and the eight B vitamins (biotin, folate, niacin,
pantothenic acid, riboflavin, thiamin, vitamin B6, and vitamin
B12) dissolve in water, so excess amounts are excreted (watersoluble vitamins)
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Vitamin A = Retinol,
retinaldehyde, retonoic acid
(performed) and carotenoids
(provitamin A)
Vitamin B1 = Thiamin
Vitamin B2 = Riboflavin
Vitamin B6 = Pyridoxine,
pyridoxal, pyridoxamine
Vitamin B12 = Cobalamin
 Vitamin C = Ascorbic Acid
 Vitamin D = Calciferol
 Vitamin E = Tocopherol,
tocotrienol
 Vitamin K = Phylloquinone
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Function – Promote Vision and Growth, prevent drying of skin
and eyes
Food Sources – Performed (Liver, fish oils, fortified milk and
eggs)
Proformed (Dark leafy green, yellow orange
vegetables & fruits
Deficiency – Cause night blindness, skin changes and nutritional
anaemia
Those at risk – Urban poor, breast fed infants (mother’s poor
diet) elderly, schoolchildren (poor veg. intake)
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Function – Calcium absorption, regulate bone metabolism,
healthy immune system
Food Sources – Herring, eel, salmon, tuna, milk, some fortified
cereals, pork sausage, egg yolk (sunlight)
Deficiency – Rickets in children, Osteomalacia in adults
Those at risk – Elderly (stay indoors) People living in Northern
Climate, People with fat malabsorption
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Function – Antioxidant, protects cells from attacks by free
radicals, role in iron metabolism
Food Sources – Vegetable oils, nuts, seeds, green leafy
vegetables and a variety of fish
Deficiency – Nerve degeneration
Those at risk – Premature infants, smokers, people with fat
malabsorption
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Function – Role in coagulation process (blood-clotting)
Food Sources – Liver, green leafy vegetables, broccoli, peas and
green beans
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Deficiency – Bleeding disorders, fractures
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Those at risk – People taking antibiotics for long periods
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Function – Aids in calcium / iron absorption, immune functions
Food Sources – Citrus fruits, potatoes, green peppers,
cauliflower, broccoli, strawberries
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Deficiency – Scurvy, fatigue, bleeding gums and joints
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Those at risk – Infants, elderly, alcoholics, smokers
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The major minerals present in the body include sodium,
potassium, chloride, calcium, magnesium, phosphorus, and
sulfur.
Trace minerals are present (and required) in very small amounts
in the body. The most important trace minerals are iron, zinc,
copper, chromium, fluoride, iodine, selenium and manganese.
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Adults are 60-70% water
Functions - Maintain the health and integrity of every cell in the
body.Help eliminate by-products of the body’s metabolism,
excess electrolytes (sodium & potassium). Regulate body
temperature through sweating.
Dehydration occurs when the water content of the body is too
low. This is easily fixed by increasing fluid intake. Symptoms of
dehydration include headaches, lethargy, mood changes and
slow responses, dry nasal passages, dry or cracked lips, darkcoloured urine, weakness, tiredness, confusion and
hallucinations.
Recommended intake depends on age, hot environment etc.
Averages between 6-10 cups/day