DR VISHNU KUMAR PROFESSOR AND HOD BIOCHEMISTRY, MADHAV PRASAD TRIPATHI GOVERNMENT MEDICAL COLLEGE, SIDDHARTH NAGAR, UTTAR PRADESH.

1. NUTRITION
BI 8.1 TO 8.5
Dr. Vishnu Kumar
Professor & Head, Department of
Biochemistry, MPTMC, Siddharthnagar
vkawasthi@hotmail.com
madhwapur1976@gmail.com

2. Learning Objectives
• Nutritional importance of
carbohydrates
• Nutritional importance of fat
• Glycemic Index
• Balanced Diet
• Protein Energy Malnutrition

3. Nutritional importance of carbohydrates
• Provides major fraction of body’s energy needs.
• Calories derived is about 50% - 70% of total
calories.
• Two groups
(a) Available carbohydrate:
That can be metabolised by the body to give
energy.
(b) Unavailable carbohydrate:
Constitute only dietary fiber.

4. • Major dietary polysaccharide is STARCH
which is digested by amylase and hydrolysed
to glucose.
• Glucose is the major source of fuel for organs
and tissues
• Cane sugar is used as sweetening agent which
contains SUCROSE.

5. DIETARY FIBER
• The unavailable or indigestible carbohydrate in the diet is
called Dietary Fiber (non – starch polysaccharides).
• Requirement is 30g/day.
Types:
(a) Insoluble fiber:
Beneficial in colonic function. E.g. Cellulose and lignin
(b) Soluble fibers:
Lowers blood cholesterol level by binding bile acid and delay
the post prandial rise in blood glucose. E.g. legumes and
fruits

6. IMPORTANCE
• Improves bowel motility.
• Prevents constipation.
• Decreases reabsorption of bile salts thus lowering
cholesterol level.
• Improves glucose tolerance.
• Has hypoglycemic and hypolipidemic effect.
• Provides a feeling of fullness without consumption of
excess calories.

7. FIBER PHYSIOLOGICAL EFFECT
Cellulose
(Polymer of
glucose)
Retains water in feces, increases
peristalsis and bowel action.
Hemi cellulose
(pentose, hexose
and uronic acid)
Retains water in feces,
increases bile acid excretion.
Lignin
(aromatic alcohol)
Antioxidant, increases bile acid
excretion, hypocholestrolemic.
Pectins Absorbs water, slows gastric emptying,
increases bile acid excretion.
Mucilage Binds bile acids and lowers cholesterol
level, improves glucose tolerance.

8. Nutritional importance of fats
• Requirement of visible fat is 20g/day, in
pregnancy 30g/day and during lactation 45g/day.
• FA ingested is contributed by either Long chain
saturated FA (palmitic acid & stearic acid) or
MUFA (oleic & palmitoleic acid).
• Coconut oil is composed of medium chain FA.
• PUFA are present in vegetable oil and fish oils.
• Animal fat is predominantly saturated.

9. Importance of essential fatty acids
• Archedonic, Linoleic acid and linolenic acid are
Essential FA.
• They are components of phospholipids and form
biomembranes.
• Required as precursor of prostaglandins and
leukotrienes.
• Required for esterification and excretion of
cholesterol.

10. • They are hypocholesterolemic and
therefore
ANTI ATHEROGENIC.
• Omega-3 FA from fish oils decrease the
plasma lipoproteins (VLDL & LDL).
• Therefore they decrease the risk of CAD.

11. Cholesterol and its importance
• Egg yolk, liver, brain, kidney are rich
in cholesterol.
• Vegetables, Cereals and pulses do not
contain cholesterol.
• Vegetable sterols will inhibit cholesterol
absorption.

12. • Has atherogenic effect and may lead
to CAD.
• Hence dietary intake must be restricted.
• Should be limited in normal and avoided in
high risk people.

13. • Saturated fats raise serum cholesterol
but unsaturated fat lowers.
• So unsaturated fat (vegetable oil & fish
oil) are preferred.
• High fiber content also reduces serum
cholesterol, lowers LDL & raises HDL.

14. Glycemic Index
• Glycemic index (GI) is a ranking system
for carbohydrates based on their effect on
blood glucose levels.
• It compares available carbohydrates in
individual foods, providing a
numerical, evidence-based index of
postprandial glycemia.

15. • Carbohydrates that break down rapidly during
digestion have the highest glycemic indices.
• Carbohydrates that break down slowly,
releasing glucose gradually into the blood
stream, have a low glycemic index.

16. • A lower glycemic index suggests slower
rates of digestion and absorption of the
sugars and starches in the foods.
• Also indicate greater extraction from the
liver and periphery of the products of
carbohydrate digestion.

17. • It is assessed by GTT (glycemic response) after
a particular diet and comparing it with a
reference meal.
• The reference meal is always 50gm of glucose.
Incremental area under glucose tolerance
curve after 50gm of test meal
• GI = X 100
Incremental area under curve after 50gm
of reference meal (glucose)

18. • Simple carbohydrates like glucose or sugar will
have high GI.
• But same quantity of complex carbohydrate
like starch have low GI i.e., they will not
increase blood sugar as much.
• GI of complex carbohydrate is lesser than
cane sugar.
• GI of a carbohydrate is lowered if it is
combined with protein, fat or fiber,
preferable at least two of the three.

19. Classification GI
range
Examples
Low GI < 55
most fruit and vegetables
(except potatoes), whole
grains, milk, peanut, ice
cream.
Medium GI 56 - 69
sucrose, candy bar, some
brown rice, banana.
High GI
> 70 corn flakes, potato, white
rice, bread
Glycemic Index of common food items

20. • A low GI food will release glucose more
slowly and steadily.
• A high GI food causes a more rapid rise
in blood glucose levels and is suitable for
energy recovery after exercise or
for a person with diabetes experiencing
hypoglycemia.

21. POTATO

22. Balanced Diet
• A balanced diet must contain
carbohydrate, protein, fat,
vitamins, mineral salts and
fiber.
• It must contain these
things in the correct
proportions .
• A balanced diet should
contain calories from
carbohydrate, proteins and
fat in the ratio of 60:20:20.

23. • Carbohydrates:
provide a source of energy.
• Proteins:
provide a source of materials for
growth and repair.
• Fats:
provide a source of energy and
contain fat soluble vitamins.

24. • Vitamins:
required in very small quantities to keep you
healthy.
• Mineral Salts:
required for healthy teeth, bones, muscles etc..
• Fiber:
required to help your intestines function
correctly; it is not digested.

25. Prescription of diet
The things should be taken into account:
• Ideal body weight to be preserved.
• Protein requirement.
• Calorie requirement.
• Specific dynamic action.

26. Ideal body weight
• Under wt person should be given more
nutrients.
• Over wt person should reduce calorie intake.
Protein requirement
• Roughly calculated as 1gm/kg for adult and
2gm/kg for children.
• During pregnancy and lactation requirement is
2.5gm/kg

27. Calorie requirement
• Depends on age, sex, ht, wt, health status,
physiological activity and occupation.
Specific dynamic action (SDA)
• Expenditure of energy by SDA should also be
taken into account.

28. Calories per gram
Protein 1 Gram = 4.2 Kilo calories
Carbohydrates 1 Gram = 4 Kilo calories
Fat 1 Gram = 9 Kilo calories

29. Steps in prescription of diet
• Identify the requirement.
• Requirement of proximate principles.
• General composition of food.
• Determine the items of food.
• Three meals per day.

30. When a balanced diet is not consumed by a
person for a sufficient length of time , it leades to
nutritional disorders.
This status is called malnutrition.
Malnutrition is a pathological state resulting from a
relative or absolute deficiency or excess of one
or more essential nutreints. It is of two forms :
• Undernutrition
• Overnutrition

31. Ideal body weight
wt in kg ( 150cm = 1.50m)
ht in m²
18.5 or less Underweight
18.5 to 24.99 Normal Weight
25 to 29.99 Overweight
30 to 34.99 Obesity (Class 1)
35 to 39.99 Obesity (Class 2)
40 or greater Morbid Obesity

34. How Many Calories Does Your Body Need?
• sedentary people: Weight x 14 = estimated
cal/day
• moderately active people: Weight x 17 = estimated
cal/day
• For active people: Weight x 20 = estimated
cal/day

35. Protein –energy malnutrition (PEM)
• Most widespread nutritional problem in developing
countries.
• Kwashiorkor - Protein deficiency.
• Marasmus - Protein & calorie deficiency

36. PEM
Features Marasmus Kwashiorkor
1.Age of onset < 1yr 1- 5yr.
2.Deficiency calorie & protein protein
3.Reason early weaning starchy diet
infections
4.Growth retardation +++ +
5.Attitude irritable lethargic
6.Appearance shrunken, dehydrated plump (edema)
7.Appetite normal anorexic
8.Skin dry cracking
9.Hair no change soft, thin
10.Muscle weak wasting
11.Serum albumin 2-3g / dl <2g / dl
12.Serum cortisol ↑ ↓

37. Kwashiorkor

38. Marasmus

39. Obesity
It is defined as excess fat in the body. Obesity is
the result of disturbed relationship between
three components of energy-
• Input in form of energy
• Expenditure of energy
• Energy storage

40. • Primary obesity is not associated with a clinical
disorder .
• Secondary obesity is associated with clinical
disorder such as endocrinological disorder or
drug therapy

41. Causes-
• Metabolic
• Hormonal
• Genetic
• Environmental

42. • Obesity is associated with increased adipose
stores in subcutaneous tissues, skeletal muscle,
organs like liver.
• There is increase in size and number of
adipocytes.
• Excessive no. of adipocytes signals the body to
synthesize more TAG, so that they can be filled ,
leading to an exess of stored fat.

43. Treatment
• Dietary restriction
• Life style change
• Drugs
• Surgery

44. Thank You