2004 dr. hamda qotba 1 essential food elements by dr hamda qotba, b.med.sc, m.d, abcm
TRANSCRIPT
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Objectives
1 )Introduction of important terminology
2 )To know the function, source, structure of carbohydrates, proteins, and fat
3 )Side effects of excess and insufficient intake of EFE
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Terminology you have to know
Nutrition:
Process by which living organism receives material and uses them to promote it’s vital activities
Nutrient:
Any substance which is digested and absorbed to promote body function
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Diet:
Selection of food which is normally eaten by person or population
Food:
Substance when eaten , digested, absorbed provide at least one nutrient
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Balanced diet :Diet that provide adequate amount of all nutrients
Malnutrition:
Caused by incorrect amount of nutrient intake
Nutritional status:
Health status that produced by balanced between requirements and intake
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Nutritional assessment:
Measurement of nutritional status by anthropometrics , biochemical data, dietary history
Dietitian:
Persons who applies science of nutrition to people in health and disease
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Metabolism:
Changes taking place in the body as result of body activityAnabolism:
Complex molecules are synthesized from simpler onesCatabolism:
Complex molecules are broken to simpler ones
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Carbohydrates
• Starch , sugar • Broken in the body to produce
heat and energy• Oxidation of carbohydrate in
the body produce CO2 and H2O• 1g ---- 16 kj (4kcal)
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Structure • Monosaccharides:
Glucose , fructose and galactose • Disaccharides:
Sucrose , lactose and maltose• Polysaccharides:
Amylose: straight chain of 70-350 glucose
Amylopectin: branched chain of 100000 glucose
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Sources of carbohydrates
• Glucose ------ fruits • fructose ------ honey• sucrose ------ beet, cane• lactose ------- milk• Galactose ---- digestion of lactose• maltose ------ sprouting grains• starch ------ grains, unripe ft+veg.• Glycogen---- liver, muscles• Cellulose ------ cereals, veg., cell wall as fiber
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Properties & uses
• Sweetness differs fructose lactose • Glucose --- added for food when
high energy required • Fructose --- sweetener in diabetes • Sucrose -- sweetener &
preservative• Glucose syrup ---- jam
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Digestion & Absorption
• Starch pancreatic amylase maltotriose
• Disaccharidases sucrose, maltose, lactose
monosaccharide carbohydrate are absorbed in the single
form
• Absorbed by intestinal villi then travel by blood stream to the liver through the portal vein
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Utilization
1. Used as fuel to produce energy for cell activity
2. Glycogen (glucose, galactose, fructose) is synthesized in liver and muscle and it’s used for muscular work
3. Converted into fat when liver and muscle are full with glycogen
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Blood sugar level & Hormonal control
• 65-180 mg/dl
• Insulin β pancreatic cell assessing passage of glucose to cell
• Adrenaline adrenal medulla
glucose from the break down of glycogen in liver
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• Glucagon pancreatic cell glucose from the break down of glycogen in liver
• Growth hormone pituitary gland
antagonize insulin
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Intake
• Traditional food consists mainly of carbohydrate like rice, wheat, corn, honey, jam, fruits and veg.
• Excess intake obesity
• lack intake ketosis
• lack intake depletion of body tissue
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Fat
• Carbon, Hydrogen, and Oxygen • Glycerol + 3 fatty acid triglyceride • Fatty acid e.g stearic, palmitic, oleic • Saturated = single bond, stable• Unsaturated = double bond, less stable• Bond converted from double
Unsaturated to single Saturated=hydrogenation
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Hydrogenation• Change chemical and physical -
>harder, raise melting point• Saturated= single bond (palmitic,
stearic[lard] )• Monosaturated= 1double bond
(oleic[olive])• Polyunsaturated= > 1double bond
(linoleic[corn])
More hydrogen is introduced chemically
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Rancidity & Solubility
• In dairy product is due to liberation of free fatty acid as a result of hydrolysis of triglyceride by bacteria.
• Non dairy product exposure to O2 cause oxidation
• Emulsion: suspension of minute particle
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Sources
• Animal high in cholesterol
(fat, butter, egg, milk)• Vegetable plant sterols that are poorly
absorbed by man, not cholesterol (olive , cotton, corn)
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Digestion • In the duodenum fat pancreatic lipase
f.f.acid+monoglyceride• Enter mucosal cell to form
triglycerides, combine with protein and cholesterol to form lipoprotein
• The remainder are absorbed into portal circulation as fatty acid and glycerol
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Function
• Provide energy 37kj -> 9kcal/g
• Incorporation into body structure brain and nervous system
• Protection cover vital organs
• Insulation prevent heat loss from the body
• Satiety• Fat soluble vitamins ADEK
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Stores & intake
• Under skin, around abdominal organs
• There’s no definite amount of fat is known to maintain health
• Food as fat source:1. High fat sources= >10%2. Moderate fat sources= 3-10%3. Poor fat sources = <2%
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Essential fatty acid
• They are polyunsaturated fatty acid needed for the body (linoliec, linolenic, arachinodic)
• Deficiency due to malabsorption or prolonged IV intake
• Vit. E important in preserving there chemical structure
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• Cholesterol synthesized in the liver, attach
it self to lipoprotein to be able to transfer in the body
LDL bad cholesterol (<160mg/ml) HDL good cholesterol
(>40mg/ml)
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• PhospholipidFatty material, integral part of
the body (brain, nervous system)
Present in blood plasma• Lipoprotein Plasma protein in which fat
combine with them to be in the soluble form in the plasma
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Proteins
• Principle constituent of the cell • Composed of amino acid• Animal synthesis protein from
A.A but not vice versa • Plant synthesis A.A from CO2,
H2O, Nitrogen • Protein is the only source of
nitrogen in the body
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• By shape fibrous, globular• Protein in food like: myosin meat Albumin, vitellin egg Casein milk gluten wheat
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Essential Amino Acid
• A.A that the body are unable to make or make in insufficient amount
Histidine lysine methionineValine leucine isoleucineTryptophan phenylalanine
threonine
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• Biological value Protein food that contain all A.A in the proportion needed for man is said to be high biological value (egg, human milk)
• Limiting A.A essential A.A that food lack wheat lysine
soya beans methionine maize trypyophan
• This problem can be overcome by eating food that contains needed A.A
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Function
• Replace protein loss (wear & tear )
• Produce new tissue (growth, pregnancy)
• Manufacture o new protein (enzyme)
• Source of energy
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Nitrogen balance
• 6g protein 1g nitrogen • To be in nitrogen balance
intake=output
• Normal lose 14g • +ve nitrogen balance intake
>loss (growth)• -ve nitrogen balance intake <
loss (burns)
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Digestion, absorption & excretion
• Stomach proteolytic enzyme large polypeptides
• Duodenum pancreatic enzyme peptides+A.A
• peptides+A.A enter the intestinal cell:
1. Build structural proteins2. Converted to other A.A3. Produce energyExcreted by kidney in the form of urea
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Intake
• If Insufficient impair healing& increase infection
• Deficiency may arise as a result of:
1. If energy requirement increase 2. Burn , fracture, injuries3. Failure to utilize protein4. Excessive loss
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Protein Energy Malnutrition (PEM)
• Kwashiorkor lack of protein, other energy
sources• Result in growth retardation,
infection, slow recovery, • Signs
edema, muscle wasting ,liver enlargement, change in pigmentation