2004 Dr. Hamda Qotba 1

Essential Food Elements

By

Dr Hamda Qotba, B.Med.Sc, M.D, ABCM

2004 Dr. Hamda Qotba 2

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

2004 Dr. Hamda Qotba 3

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

2004 Dr. Hamda Qotba 4

Diet:

Selection of food which is normally eaten by person or population

Food:

Substance when eaten , digested, absorbed provide at least one nutrient

2004 Dr. Hamda Qotba 5

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

2004 Dr. Hamda Qotba 6

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

2004 Dr. Hamda Qotba 7

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

2004 Dr. Hamda Qotba 8

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)

2004 Dr. Hamda Qotba 9

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

2004 Dr. Hamda Qotba 10

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

2004 Dr. Hamda Qotba 11

Properties & uses

• Sweetness differs fructose lactose • Glucose --- added for food when

high energy required • Fructose --- sweetener in diabetes • Sucrose -- sweetener &

preservative• Glucose syrup ---- jam

2004 Dr. Hamda Qotba 12

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

2004 Dr. Hamda Qotba 13

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

2004 Dr. Hamda Qotba 14

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

2004 Dr. Hamda Qotba 15

• Glucagon pancreatic cell glucose from the break down of glycogen in liver

• Growth hormone pituitary gland

antagonize insulin

2004 Dr. Hamda Qotba 16

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

2004 Dr. Hamda Qotba 17

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

2004 Dr. Hamda Qotba 18

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

2004 Dr. Hamda Qotba 19

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

2004 Dr. Hamda Qotba 20

Sources

• Animal high in cholesterol

(fat, butter, egg, milk)• Vegetable plant sterols that are poorly

absorbed by man, not cholesterol (olive , cotton, corn)

2004 Dr. Hamda Qotba 21

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

2004 Dr. Hamda Qotba 22

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

2004 Dr. Hamda Qotba 23

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%

2004 Dr. Hamda Qotba 24

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

2004 Dr. Hamda Qotba 25

• 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)

2004 Dr. Hamda Qotba 26

• 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

2004 Dr. Hamda Qotba 27

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

2004 Dr. Hamda Qotba 28

• By shape fibrous, globular• Protein in food like: myosin meat Albumin, vitellin egg Casein milk gluten wheat

2004 Dr. Hamda Qotba 29

Essential Amino Acid

• A.A that the body are unable to make or make in insufficient amount

Histidine lysine methionineValine leucine isoleucineTryptophan phenylalanine

threonine

2004 Dr. Hamda Qotba 30

• 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

2004 Dr. Hamda Qotba 31

Function

• Replace protein loss (wear & tear )

• Produce new tissue (growth, pregnancy)

• Manufacture o new protein (enzyme)

• Source of energy

2004 Dr. Hamda Qotba 32

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)

2004 Dr. Hamda Qotba 33

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

2004 Dr. Hamda Qotba 34

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

2004 Dr. Hamda Qotba 35

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

2004 Dr. Hamda Qotba 36

Protein Energy Malnutrition (PEM)

• Marasmus lack of energy and protein• Sings muscle wasting, loss of S.C fat,

growth retardation

Overcome by breast feeding, nutritional supplement, nutrition education

and improve sanitation