1. NUTRITION AND HEALTH Dr. Bhupesh Gupta
MBBS MD

2. INDEX
• Classification of Foods
• Nutrients
• Proteins
• Fats
• Carbohydrates
• Vitamins
• Fat Soluble Vitamins
• Water Soluble Vitamins
• Minerals
• Other Trace Elements
• Food Groups

3. Energy Requirements
• Balanced Diet
• Food Hygiene
• Food Related Diseases (Public Health Nutrition Problems)
• Diet Survey
• Indicators of Malnutrition
• Nutritional Surveillance
• National Nutrition Policy

4. INTRODUCTION
Food It is a substance consumed, other than water and drugs, for
maintaining the health, well-being and vitality of the individual.
Nutrient It is a chemical factor (active ingredient) present in food item, which
determines the quality of food and in turn the health of the individual. For
example, proteins, fats, carbohydrates, vitamins and minerals.
Nutrition It is that branch of science, which deals with the study of a
dynamic process, in which the consumed food is utilized for nourishing the
body (a process of assimilation of food).
Dietetics It is the science that deals with the study of nutrition in health and
disease (i.e. planning of meals for the healthy and the sick).
Balanced Diet It is the diet consisting of right kinds of foods in right
proportions, as to provide the required energy and proximate principles for
maintaining the health, vitality and well-being and makes small provision to
withstand short duration of illness.

5. CLASSIFICATION OF FOODS
By origin: Foods of animal origin; Foods of vegetable origin.
By chemical composition: Proteins, fats, carbohydrates, vitamins and
minerals.
By function: Body building foods (Foods rich in proteins. For example,
meat, fish, milk, egg, pulses, etc.). Energy yielding foods (Foods rich
in fats and carbohydrates. For example, cereals, sugar, ghee, oil,
etc.). Protective foods (Foods rich in vitamins and minerals. For
example, fruits, vegetables, etc.).
By nutritive value: Cereals and millets, pulses, vegetables, nuts and
oil seeds, fruits, animal foods, fats and oils, sugar and jaggery,
condiments and spices, miscellaneous foods

6. NUTRIENTS
These are grouped into two groups—macro- and micronutrients.
Macronutrients They are so called because they are required in large
quantities and so they constitute the main bulk of the food. They are
often called ‘Proximate principles’. For example, proteins, fats and
carbohydrates. Their contribution in the food is as follows:
Proteins—7 to 15 percent
Fats—10 to 30 percent
Carbohydrates—65 to 80 percent
Micronutrients They are so called because they are required in small
quantities (varying from micrograms to milligrams). For example,
vitamins and minerals.

7. PROTEINS
Each molecule of protein is made up of large number of units called
‘amino acids’, linked by peptide chains. There are about 22 amino
acids, which are grouped into ‘Essential’ and ‘Non-essential’ amino
acids.
Essential ones are 8 in number and they are so called because they
are not synthesized in the body in required amounts and they are
essential to the body. Therefore they have to be obtained from
dietary proteins. They are leucine, isoleucine, lysine, methionine,
phenylalanine, threonine, tryptophan and valine. In addition, growing
children require Histamine.
Non-essential amino acids are so called because they are synthesized
in the body. It does not mean that they are not essential to the body.
Both essential and non-essential amino acids are needed for
synthesis of tissue proteins.

8. FUNCTIONS OF PROTEINS
• They are essential for growth and development of the body (Body
building)
• They are essential for the repair of the tissues (wear and tear)
• They are the constituents of enzymes, hormones, antibodies,
plasma and hemoglobin
• They maintain osmotic pressure and thus maintain fluid balance in
the body
• They provide energy (1 g provides 4 kcals of energy)
• They maintain the hydrogen ion concentration of the body fluid
thus maintain the acid-base balance

9. The daily requirement of proteins is 1 g/kg body weight for adults
Sources: There are two main sources:
A. Animal sources: Meat, milk, egg-white, fish, cheese, etc. All these
animal proteins contain all the essential amino-acids. Hence they are
called First class proteins. However, the egg-proteins are considered
to be the best animal protein, because of its high biological value and
digestibility. Hence, egg protein is called ‘Reference protein’.
B. Vegetable sources: These are cereals, pulses, beans, nuts, oil-seed
cakes, etc.

10. EVALUATION (ASSESSMENT) OF
PROTEINS
Proteins are evaluated by the following parameters:
i. Digestibility coefficient
ii. Biological value
iii. Net protein utilization
iv. Amino acid score
v. Protein efficiency ratio
vi. Protein-energy ratio.

11. FATS
These are the compounds of glycerol (glycerin) and fatty acids.
Fatty acids: These are grouped into 2 groups—saturated and
unsaturated.
Saturated fatty acids: These are primarily derived from animal sources
(except coconut oil). For example, lauric, palmitic and stearic acids.
They can be synthesized in the body during the catabolism of
proteins and carbohydrates.
Unsaturated fatty acids: These are primarily derived from vegetable
sources. These are further divided to monounsaturated (MUFA, e.g.
Oleic acid) and polyunsaturated fatty acids (PUFA, e.g. Linoleic acid)
former can be synthesized in the body but the latter cannot be
synthesized in the body.

12. FUNCTIONS OF EFA
• They maintain the integrity of the skin (smoothness and
healthiness)
• They (EPA and DHA) reduce the serum cholesterol in the blood by
transportation
• They maintain enzyme system in the body
• They help in the synthesis of prostaglandins
• DHA is especially active in retina and cerebral cortex.

13. SOURCES OF FAT

14. CARBOHYDRATES
This constitutes the main bulk of our diet
The carbohydrates are grouped into monosaccharides (having single
unit, e.g. glucose, galactose, fructose, ribose). Disaccharides (having
two carbohydrate units, e.g. lactose, maltose, sucrose) and
polysaccharides (having more than two units, e.g. starch, cellulose).
Mono and disaccharides are sweet and are soluble in water, whereas
polysaccharides are not sweet and are insoluble in water.
Starch is present in cereals, millets, roots and tubers. Thus it is the
chief source of our energy.
Cellulose is a fibrous substance (dietary fiber) present as lining in the
cereals and pulses, fruits and vegetables. It has no nutritive value.

15. FUNCTIONS
1. Carbohydrate serves as a main source of energy. One gram of CHO
yields 4 kcals of energy.
2. It is essential for the oxidation of fat (Fats are burnt in the fire of
carbohydrate).
3. Carbohydrate is stored as glycogen in the liver and muscles. The
reserve is rapidly exhausted when the person starves.
4. Excess of carbohydrate is stored as fat in the body.
5. It acts as a structural unit of nervous system, as cerebroside.
6. It exerts protein sparing action.
7. It adds flavor and texture to the food and increases palatability.

16. Main sources of CHO are cereals, pulses, fruits, roots and tubers.
Sugar, jaggery and honey are 100 percent carbohydrates.
The CHO content of flesh foods is negligible.
Daily requirement: It is 400 to 500 g. CHO should constitute nearly
60 to 70 percent of total energy requirement of the body.

17. DIETARY FIBER
This is an inert component of carbohydrate with little nutritive value.
It is a non-starch polysaccharide. It is found in vegetables, fibrous
fruits (pineapple), brans and whole grains as lining. It is hardly found
in animal foods. It includes cellulose and non-cellulose
polysaccharides such as hemicellulose, pectin, lignin, inulin.

18. FUNCTIONS
• Dietary fiber (soluble fiber) will bind cholesterol of the food and prevents
its absorption and eliminates it through stools, reduces serum cholesterol
level. Thus it is associated with reduced risk of atherosclerosis.
• Low fiber diet is associated with less fecal volume and constipation,
resulting in higher concentration of carcinogens ingested in the food. Bowel
mucosa exposed to this higher concentration of carcinogens for an unduly
long period, predisposes for cancer of colon.
• Fiber acts as a scavenger-cum-vehicle to remove tissue debris and other
unwanted materials from intestine through stools.
• Fiber facilitates, the normal peristaltic movements of the intestine.
• Soluble fiber prevents gallstones and obstructive jaundice. It also slows
down the absorption of glucose, hence good for diabetics.
• Thus, fiber is an essential nutrient in its own way, even though by itself is
a non-nutrient. An average diet should include 40 g of fibers per day.

19. MICRONUTRIENTS
Micronutrients include vitamins and minerals.
Of all the micronutrients, four are most important, namely iodine,
iron, zinc and vitamin A. They are important for immunity,
intelligence, reproduction and work capacity.
They cannot be synthesized endogenously and have to be supplied in
diet.
Micronutrient deficiencies result from inadequate dietary intake, poor
absorption from gastrointestinal tract, excessive losses, increased
requirements or a combination of these factors.

20. VITAMINS
They do not provide energy unlike macro-nutrients, but they enable
the body to use other nutrients.
Vitamins are grouped into 2 groups:
I. Fat soluble vitamins: These are vitamins A, D, E and K.
II. Water soluble vitamins: These are vitamin B complex group and
vitamin C.

21. FAT SOLUBLE VITAMINS
Vitamin A
This occurs in two forms, as retinol in animal foods and as b-carotene in
plant foods.
Functions
• Vitamin A helps in the synthesis of a pigment called ‘Rhodopsin’ in the
retina of the eye, which is necessary for the normal vision, especially in the
dim-light for dark adoptation. Thus vitamin A is indispensable for normal
vision.
• It maintains the integrity of the skin and mucous membrane of the
conjunctiva, cornea, respiratory, alimentary and urinary system.
• It promotes skeletal growth.
• It increases the immune response. Thus it is anti-infective.
• It may protect some epithelial cancers such as carcinoma of bronchus.

22. SOURCES
Animal Sources (as Retinol) These are meat, liver, fish, egg-yolk,
milk, cheese, butter, ghee. Richest source is fish liver oil (Cod liver oil
and shark liver oil).
Vegetable Sources (as b-carotene) Cheapest source is green leafy
vegetables, e.g. spinach, amaranth. Darker the green color of the
vegetables, higher the carotene content. Richest source is red palm
oil. Other sources are yellow fruits like mango and papaya. Some
roots like carrots are also rich in b-carotene.
Deficiency of vitamin A: The signs and symptoms are grouped into
ocular and extraocular manifestations.

23. OCULAR MANIFESTATIONS:
a. Night blindness (Nyctalopia) That means inability to see in the dim
light by an young child as the evening sets in.
B. Conjunctival xerosis:: The normal, smooth, shiny conjunctiva over
the sclera bec
C. Bitot’s spots: These are triangular, foamy, pearly-white or
yellowish spots on the bulbar conjunctiva.
D. Corneal xerosis: The smooth, shiny, transparent cornea looks dull
and dry, eventually it becomes opaque.
E. Corneal ulcer: The ulcer may be big or small, which after healing
leaves behind a permanent scar, which affects vision.
F. Keratomalacia: As the deficiency of vitamin A continues, the entire
cornea or a part of it becomes soft and later it is liquefied.

24. Extraocular Manifestations
• Retardation of growth
• Follicular hyperkeratosis (Phrynoderma)
• Anorexia
• Increased incidence of respiratory and alimentary infections
• Development of urinary calculi.

25. Hypervitaminoses A
An excess intake of retinol causes anorexia, vomiting followed by
sleep disorders and skin desquamation. Other features are
hepatomegaly, papilledema, bony exostoses (swelling over the long
bones), brittleness of the bones and often fractures.

27. VITAMIN D
There are two forms namely vitamin D2 (calciferol) and D3
(cholecalciferol)
Functions
• Vitamin D promotes the absorption of calcium and phosphorus in
the intestine
• It helps in the mineralization, i.e. calcification of bones and their
hardening.

28. SOURCES
Vegetable foods do not contain this vitamin:
a. Vitamin D is naturally synthesized in the body in adequate amount
on exposure of skin to UV rays of sun (explained).
b. Animal foods rich in vitamin D are fish liver oil, butter, milk, ghee
and egg-yolk.

29. DEFICIENCY CAUSES: RICKETS
AMONG CHILDREN AND
OSTEOMALACIA AMONG ADULTS.

30. Hypervitaminosis D
The margin between the daily requirement dose of vitamin D and the
toxic dose is narrow. Overdose results in nausea, vomiting, anorexia,
thirst, drowsiness. Hypercalcemia may result not only in calcification
of the tissues but may also result in cardiac arrhythmias and renal
failure.

31. VITAMIN E (TOCOPHEROL)
It has been found to have anti-oxidant property and protects
membrane phospholipid from free radical induced peroxidase
damage.
Foods rich in polyunsaturated fatty acids, e.g. vegetable oil, cotton
seed oil, sunflower oil, wheat germ oil, soybean, corn-oil, green leafy
vegetables, egg-yolk and butter are good sources.
A normal adult requires about 10 µg (15 IU) of vitamin E per day.
Infants require only 3 µg (5 IU) of alpha-tocopherol per day.

32. VITAMIN K
This occurs in two forms vitamin K1 and K2. Vitamin K1 is found in
green leafy vegetables, fruits, cheese, egg-yolk and liver.
Cow’s milk is rich in vitamin K1 (60 µg/L) than human milk (15 µg/L).
Vitamin K2 is synthesized by the bacterial flora in the human gut.
Vitamin K is stored in the liver. It plays an important role in the
formation of prothrombin, a coagulation factor

33. Deficiency of vitamin K may result either by the decreased intake or
by the long-term administration of antibiotic, suppressing the normal
intestinal flora.
However, deficiency is less frequent because of its natural synthesis
in the gut. However, deficiency of vitamin leads to low prothrombin
activity resulting in hemorrhages, by prolonging the blood clotting
time.
Daily requirement is about 0.03 mg per kg for an adult and that is
obtained by a combination of dietary intake and its synthesis in the
gut.