3. INTRODUCTION
•Nutrition may be defined as the science of food
and its relationship to health.
• Nutrient or “food factor” - proteins, vitamins
and minerals.
•Dietetics is the practical application of the
principles of nutrition; it includes the planning of
meals for the well and the sick.
•Good nutrition means “maintaining a
nutritional status that enables us to grow well
and enjoy good health.”
4. • Protein, carbohydrate and fat had been
recognized early in the 19th century as energy
yielding foods and much attention was paid to
their metabolism and contribution to energy
requirements.
5. CLASSIFICATION OF FOODS
Classification by origin:
• Foods of animal origin
• Foods of vegetable origin
Classification by chemical composition:
• proteins
• fats
• carbohydrates
• vitamins
• minerals
6. CLASSIFICATION BY PREDOMINANT FUNCTION
• Body building foods:
Meat, milk, poultry, fish, eggs, pulses etc.
• Energy giving foods:
Cereals, sugars, fats, oils etc.
• Protective foods:
Vegetables, fruits, milk, etc.
7. CLASSIFICATION BY NUTRITIVE VALUE
• Cereals and millets
• Pulses
• Fruits and Vegetables
• Nuts and oilseeds
• Animal foods
• Fats and oils
• Sugar and jaggery
• Condiments and spices, etc
8. NUTRIENTS
• Organic and inorganic complexes contained in food
are called nutrients. They are broadly divided into;
Macronutrients:
• proteins
• fats
• carbohydrates
Micronutrients
• vitamins
• minerals
9. PROTEINS
• Proteins are complex organic nitrogenous
compounds.
• Proteins are made of monomers called amino
acids.
• There are about 24 different amino acids which
are found in human body.
• Of this 9 AA are termed “essential” as they are
not synthesized in human body and must be
obtained from dietary proteins.
• Leucine,isoleucine,lysine,methionine,phenylalani
ne,threonine,valine,trptophan,histidine.
10. Functions of proteins
• Body building
• Repair and maintenance of body tissues
• Maintenance of osmotic pressure
• Synthesis of bioactive substances and other
vital molecules
11. Evaluation of proteins
The parameters used for net protein
evaluation are:
• Biological value
• Digestibility coefficient
• Net protein utilization (NPU)
12. SOURCES
• Animal sources –
milk,meat,fish,egg,cheese,etc
• EAA are rich
• Vegetable sources-
Pulses,cereals,beans,nuts,etc
13. ASSESSMENT OF PROTEIN NUTRITION
STATUS
• Protein nutrition status is measured by Serum
Albumin Concentration.
• It should be more than 3.5 g/dl.
• Less than 3.5 g/dl. Shows mild malnutrition.
• Less than 3.0 g/dl. Shows moderate
malnutrition
14. FAT
• Fats are sold at 20deg.C; they are called
“oils” if thy are liquid at that temperature.
• They are concentrated source of energy.
• Most of the body fat (99percent) in the
adipose tissue constitutes between 10 and 15
percent of body weight. One kilogram of
adipose tissue corresponds to7700 kcal of
energy.
18. Fats yield fatty acids and glycerol on hydrolysis
Fats S F A M U F A PUFA
coconut
oil
92 6 2
Palm oil 46 44 10
Ground
nut oil
19 50 31
Safflowe
r oil
10 15 75
Sunflowe
r oil
8 27 65
Corn oil 8 27 65
Soya
bean oil
14 24 62
butter 60 37 3
19. Essential fatty acids are those that cannot
be synthesized by humans
• Dietary sources of EFA
Linoleic acid
Sunflower oil, corn oil, Soya bean oil, sesame oil
ground nut oil, mustard oil, palm oil, coconut oil.
Arachidonic acid
Meat, eggs, milk
Linolenic acid
Soya bean oil, leafy greens
20. Functions of fats
• They are high energy foods ,providing as much
as 9 kcal for every gram .
• Fats serve as vehicle for fat soluble vitamins.
• Fats in the body support viscera such as heart
, kidney and intestine ; fat beneath the skin
provides insulation against cold .
22. Fat requirements
In developed countries dietary fats provide 30 to
40 per cent of total energy intake . The WHO
expert committee on prevention of coronary
heart diseases has recommended only 20 to
30 per cent of total dietary energy to be
provided by fats . at least 50 per cent of intake
should consist of vegetable oils rich in
essential fatty acids.
23. Carbohydrate
Carbohydrate is the main source of energy,
providing 4 kcal per one gram Carbohydrate is
also essential for oxidation of fats and for the
synthesis of certain non-essential amino acids
24. Sources of Carbohydrate
• These are the three main sources of Carbohydrate ,
viz starches , sugars and cellulose .
• The Carbohydrate reserve ( glycogen ) of human
adult is about 500 g . this reserve is rapidly
exhausted when a man is fasting . if dietary
Carbohydrate do not meet the energy needs of the
body ,
• protein and glycerol from dietary and endogenous
sources are used by the body to maintain glucose
homeostasis .
25. Dietary fibre
• Dietary fibre which is mainly a non-starch
polysaccharide is a physiological important
component of diet. It is found in vegetables, fruits
and grains .
• Absorbs water and this increase the bulk of stool
and helps reduce the tendency of constipation.
• Associated with reduced incidence of CAD.
• CA Stomach and colon have been linked to a low
fibre diet.
26. MOST PEOPLE TEND TO
UNDERESTIMATE THEIR FOOD
INTAKE AND OVERESTIMATE
THEIR ACTIVITY LEVEL.
27. VITAMINS
• Class of organic compounds categorized as
essential nutrients.
• Micronutrients.
• Do not yield energy but enable the body to
use other nutrients .
• Each has specific function to perform and
deficiency of any particular Vitamin may lead
to specific deficiency diseases.
28. • Fat soluble Vitamins -
A, D, E and K
• water soluble Vitamins –
B group and Vitamin c.
