NUTRITION

1. Nutrition–2
Dr. ganesh,
Dept of biochemistry.

2. Nutrition
Contents:
• Nutrition–1
Essential Nutrients
Energy Nutrition
– BMR
– SDA
– RQ
Role of Carbohydrate, Fat and Protein in Nutrition
• Nutrition–2
• Quality of Food Proteins
• Balanced Diet
• Nutritional Disorders – Protein-Calorie Malnutrition

3. Nutrition – General Aspects
• Food provides
energy and other nutrients for
normal physiological
functioning,
maintenance and
growth

4. Nutrition – General Aspects
• six major classes of nutrients which are
essential –
carbohydrates, fats, protein, minerals,vitamins
and
water.
• Other accessory food factors
beneficial but not essential
dietary fiber and
antioxidants

5. Nutrition – General Aspects
• diet of an organism is
what it eats,
largely determined in animals by the
(perceived)
palatability of foods
• Nutritional science
investigates the metabolic and physiological
responses
of the body to
diet

6. Nutrition – General Aspects
• Dietitians –
health professionals who
specialize in human nutrition
trained to provide
safe, evidence-based
dietary advice and management to
individuals (in health and disease),
as well as to institutions
• Dietitians establish
nutritional standards and
recommendations including
meal planning, economics, and preparation

7. Nutrition–2
Contents
– Quality of Food Proteins
– Balanced Diet
–Nutritional Disorders –
Protein-Calorie Malnutrition

8. Background
• Dietary Sources of Protein
Good sources
Non veg. sources-meats, poultry, fish,egg
Veg sources- legumes (pulses), and milk.
cereals are not good source,
still provide considerable amounts, Because staple food
consumed in large quantities.
• Protein Requirement
Adults
0.8-1 g protein/Kg body weight/day.
nearly double for children, in pregnancy and lactation..
Calories obtained from proteins should be
10-15% of the total calorie requirement.

9. Introduction
• The quantity of dietary protein alone is not
sufficient
to provide the
nutritional requirements.
Quality dietary of proteins is also important.
• Protein quality
term used to describe
how well a protein from food provides
body's requirements and, therefore,
how useful the protein is
for our body

10. Definition
Quality refers to
proportion
of the ingested dietary protein
that is
retained by
the body

11. Factors Determining the
Quality of Dietary Proteins
• Two factors determine the quality –
1) its essential amino acid content
that correspond to human requirements
and
2) its digestibility.

12. Factors Determining the
Quality of Dietary Proteins
• Essential Amino Acid Content
all the 20 biological amino acids are required for
the synthesis of all proteins in the body
Even a single essential amino acid missing from the
diet
prevents the synthesis of proteins in the body
The unused amino acids accumulate,
are excessively catabolized and
the amino-nitrogen excreted as urea.
This results in a low utilization of that dietary
protein and
negative nitrogen balance

13. Factors Determining the
Quality of Dietary Proteins
• Essential Amino Acid (EAA) Content
AAs (inside Cells with all EAAs )
Protein Synthesis
Proteins
AAs (inside Cells, deficient in even one EAA )
Protein Synthesis
Proteins
Catabolism
Urea Synthesis & Excretion

14. Factors Determining the
Quality of Dietary Proteins
• Digestibility
essential amino acids of a dietary protein are
available to
the body only if the protein is
completely digested
Uncooked and plant proteins are
less digestible

15. Indices for Assessment of
Quality of Dietary Proteins
some of the indices used to
assess the nutritional value
of proteins:
• Net protein utilization (NPU)
• Biological value (BV)
• Protein efficiency ratio
• Chemical score

16. Net Protein Utilization: (NPU)
defined as
% of food nitrogen that is retained in the body
depends on
both - essential amino acid content and
digestibility of the protein.
• This is a better nutritional index than
biological value.

17. Net Protein Utilization: (NPU)
Nitrogen retained X 100
NPU =
Nitrogen ingested

18. Net Protein Utilization of Foods
Net Protein Utilization Food
• 91 – Egg
• 75 – Milk
• 76 – Meat
• 57 – Cereals

19. Biological Value (BV) of Proteins
defined as
the percentage of absorbed nitrogen retained in the
body.
• Nitrogen retained X 100
• BV=
• Nitrogen absorbed
• BV provides
a reasonably good index
for the nutritive value of proteins.
• But cannot take into account
• the nitrogen that might be lost due to incomplete
digestion

20. Quality of
Animal and Plant Food Proteins
complete proteins
• Animal proteins from
Eggs(Egg albumin), milk(casein), cheese, meat, and fish, are
high quality proteins
because of both the factors
– high essential amino acid content and
easy digestibility.
• Because of the presence of sufficient amounts of all the
essential amino acids
animal proteins are referred to as
complete proteins

21. Quality of
Animal and Plant Food Proteins
Incomplete proteins
• Proteins of plant source, like
cereals, legumes (pulses), nuts, vegetables and fruits
are of
low quality
lack one or more of the essential amino acids
• For the same reason referred to as
incomplete proteins.
When only such proteins are fed , there will be
growth failure .

22. Limiting amino acid
• The essential amino acid deficient in an
incomplete protein is called
limiting amino acid
Proteins of cereals and pulses are incomplete
proteins
• Cereals are deficient in lysine and
pulses are deficient in methionine,
i.e. lysine is the limiting amino acid for cereals and
methionine for pulses

23. Mutual Supplementation of Dietary
Proteins for Vegetarians
• Cereals are deficient in lysine but rich in methionine
and
pulses are deficient in methionine, but rich in lysine.
• Hence, combination of pulses and cereals
complement each other by
cancelling each other’s deficiency and provides first class
protein.
• Thus, For vegetarians, two incomplete protein sources
(e.g. rice and pulses) may be combined to make
a complete protein.
This is called mutual Supplementation of Dietary
Proteins

24. Mutual Supplementation of Dietary
Proteins for Vegetarians-examples
IDLI (cereal)
+
SAMBAR(pulse)
RICE or CHAPATHI(cereal)
+
SAMBAR(pulse)
Complete
protein

25. Balanced Diet
Contents:
• Definition
• Basic Food Groups
• Planning of a Balanced Diet
• Example of a Balanced Diet

30. Balanced Diet
• Definition of Balanced Diet
A balanced diet is one
which contains all the required nutrients
in adequate amounts
without exceeding the safe limits.
-The diet of an individual is largely determined by the
(perceived) palatability of foods

31. Balanced Diet-components
Calories
By
cereals,
pulses, fats
and oil, and
sugar
Proteins
By
pulses,meat
,fish,egg,
milk,cereals
Vitamins
and
minerals
By
vegetables,
fruits,egg,
milk
fibre
By
vegetables,
fruits and
cereals
Balanced Diet has mainly 4 components

32. Balanced Diet-components
Calories
(Kcal/day)
Sedentary-
2400
moderate-
2800
Heavy-
3000-3900
Proteins
(gms/Kg
body
weight)
Adults-1
Children-2
Pregnancy/
Lactation-
2.5
Vitamins
and
minerals
As per RDA
fibre
About
30gms/Day
How much per day??

33. Basic Food Groups
• Most foods contain more than one nutrient
but no single food item supplies all the essential
nutrients and other accessory food factors in the
amounts that are needed
• Nutrients are distributed in varying quantities in
different categories of natural foods,
Therefore, eating certain amounts of foods from different
categories is recommended for a balanced diet.
Basic food groups refers to classification of various foods
based on the common or shared nutrient content of
these types/catagories of foods.

34. Basic Food Groups
• A balanced diet should be
an intelligent assortment of food items
from basic food groups.
• There are
five
basic food groups

35. Basic Food
Groups
Food Items Major Nutrients
1. Cereal group Rice,wheat, bread,
other cereals
calorie, B-complex
vitamins,dietary
fiber, proteins
2. Protein/Meat
group
Meat,poultry,fish,
eggs,beans,pulses,
nuts
protein,fat,iron,
vitamins,minerals
3. Fruits &
Vegetable group
All varieties of
fruits and
vegetables
vitamin C,
carotenes,dietary
fiber

36. 4. Milk group milk and dairy
products
proteins,fat,
calcium,riboflavin
5. Sugar, Fats and
Oil Group
Table sugar, edible
oils, animal foods
Calorie, fat soluble
vitamins, essential
fatty acids

37. Planning of a Balanced Diet
A balanced diet should be based on:
• Estimation of nutrient requirements
based on age, sex, weight, physical activity of the
individual.
• The estimated requirements should be
obtained from all the five basic food groups.
• The food selected should be
economic, locally available, palatable and easily
digestible.
• total calories obtained from the food should be
distributed among
carbohydrates, fat and proteins as
60-65%, 30-40%, 10-15% respectively.

38. Example of a Balanced Diet
for an adult man doing moderate work
requiring 2800 Cal/day * For vegetarian diet in brackets
Food items Quantity (gm/day)
• Cereals 450
• Meat/fish (pulses)* 50 (75)*
• Egg 30
• Green leafy vegetables 125
• Other Vegetables 75
• Roots and tubers 100
• Fruits 30
• Milk 100 (200)*
• Fats & oils 25 (40)*
• Sugar 25
Total calories=2800

39. Questions??

40. • Define balanced diet. Prescribe
balanced diet for a medical student.

41. • Definition of Balanced Diet
A balanced diet is one
which contains all the required nutrients
in adequate amounts
without exceeding the safe limits.

42. •Obtained By cereals, pulses, fats
and oil, and sugar
1. calories- around
2800kcal/day
•Obtained By
pulses,meat,fish,egg, milk,cereals
2. proteins- around
1g/kg body weight
•Obtained By
vegetables,fruits,egg,milk etc
3. vitamins and
minerals- requirement
as per RDA
•Obtained by fruits and
vegetables.
4. fibre-around
30g/day
Balanced diet for a medical student should include
following.
-a medical student comes under moderate physical
activity category requiring 2800kcal/day.

43. Balanced Diet chart for medical student
requiring 2800 Cal/day * For vegetarian diet in brackets
Food items Quantity (gm/day)
• Cereals 450
• Meat/fish (pulses)* 50 (75)*
• Egg 30
• Green leafy vegetables 125
• Other Vegetables 75
• Roots and tubers 100
• Fruits 30
• Milk 100 (200)*
• Fats & oils 25 (40)*
• Sugar 25
Total calories=2800

46. Nutritional Disorders-Malnutrition
Mainly 2 types.
Under nutrition
Insufficient
consumption of
nutrients
Over nutrition
Over-
consumption of
nutrients

47. Nutritional Disorders/Malnutrition
Malnutrition refers to
insufficient,
excessive, or
imbalanced
consumption of
nutrients

48. Nutritional Disorders/Malnutrition
• Under-nutrition can have an injurious
impact on health,
causing deficiency diseases such as
scurvy,
beriberi,
night blindness,
rickets,
protein-energy malnutrition
(marasmus & kwashiorkor) and

49. Nutritional Disorders/Malnutrition
over-nutrition can result in common
chronic disorders like
obesity,
cardiovascular disease,
diabetes mellitus and metabolic syndrome

50. Protein-Energy Malnutrition
• Protein-energy malnutrition encompasses
a range of disorders of starvation and
malnutrition.
• involves deficiencies of
protein and energy-providing
carbohydrates and fats.
(DEFICIENCY OF PROTEIN+CALORIES )
• frequently accompanied by
deficiency of other nutrients also such as
vitamins and minerals

51. Protein-Energy Malnutrition
• common in populations of developing countries
(low-income countries) of
Asia, Africa and South America
suffering from
chronic food shortage or famine
• but can occur in developed countries
in deprived individual or
those suffering from eating disorders –
• bulimia nervosa
or
• anorexia nervosa

53. Protein-Energy Malnutrition
Mainly 2 types
1.
Marasmus
Primary calorie
deficiency with
2ndary protein
deficiency
2.
Kwashiorkor
Primary protein
deficiency with
2ndary calorie
deficiency

54. Protein-Energy Malnutrition
• In severe form,
occurs in growing children
usually under five years of age.
• Two extreme forms are recognized:
marasmus and
kwashiorkor.
• There are also conditions that are
intermediate between
these two extreme forms
and are called
marasmic kwashiorkor

55. Marasmus
-Primary calorie deficiency with 2ndary
protein deficiency
-severe deficiency of nearly all nutrients,
• affects infants below the age of one year.
Causes
- exclusive breast milk feeding of the child by
malnourished mother for prolonged period
without any supplementation with other
foods.
- early weaning with low calorie food such as
rice water, dilute milk etc.

56. Marasmus
Clinical Features
• Child is grossly emaciated, skinny ,grossly underweight
-”All skin and bone” appearance-sunken eyes,
prominent ribs. Hence called “wasting disease”
-characteristic monkey face or old man’s face
-depletion of subcutaneous fat and muscles.-marked muscle
wasting
• Other characteristic signs are
irritability, excessive crying and stunted growth-delayed
mile stones.
appetite increased- child has hungry look.
- NO OEDEMA

57. Marasmus
Biochemical Changes
• Not much alteration of biochemical
parameters
is seen
except there may be anemia and
decrease of BMR

63. Kwashiorkor
Cause
Clinical Features
Biochemical Changes
Treatment

64. Kwashiorkor
• Primary deficiency of protein
with adequate calories
• affects mostly children
of the age group 1 to 5 years and
Those
Cause
-early weaning from breast milk with
foods deficient in both the quantity and quality of
protein. (e.g.; starchy diet, no milk or dilute milk)
“Called disease of deposed child”
-Kwashiorkor is often precipitated by increased protein
demand such as infection.

65. Kwashiorkor
Clinical features
• child will often have
deceptively plump appearance
due to edema.
Puffy face—”moon face”
• Other characteristic manifestations are
- apathy, lethargy
-hair changes-dry, brittle, discolored hair,
-marked skin lesions
-decreased resistance to infection,
-diarrhea, and retarded growth
-Appetite- decreased

66. Kwashiorkor
Biochemical Changes
• Serum albumin is decreased
(less than 2 gm/dL;
normal value = 3.5 to 5.5 gm/dL) and
is the cause for
edema.
• Other frequent finding is
fatty liver
due to
decreased apolipoprotein synthesis
(and therefore, decreased VLDL synthesis) in the
liver,
leading to
decreased mobilization of triglyceride from
the liver.

67. Kwashiorkor

72. Kwashiorkor
Treatment
• Treatment involves
introduction of foods
rich in both
quantity and
quality of
protein

73. feature marasmus kwashiorkor
Age of onset Less than 1y 1-5y
deficiency calorie protein
edema absent present
appearance Emaciated,
monkey face
Plump,
moon face
appetite Normal or
increased
decreased
Skin and hair normal Lesions are seen
Muscle wasting Present +++ Present but cant
be seen becoz of
oedema

74. Age of onset Less than 1y 1-5y
deficiency calorie protein
edema absent present
appearance Emaciated,
monkey face
Plump,
moon face
appetite Normal or
increased
decreased
Skin and hair normal Lesions are seen
Muscle wasting Present +++ Present but cant
be seen becoz of
oedema
Serum albumin normal decreased

75. Few Myths About Food…..
Non-veg food gives more strength than veg
food..
Consumption of papaya in pregnancy leads
to abortion..
Taking more of vitamin supplements will
boost health..
Tender coconut water is ideal drink for sick
and debilitated patients.
Meat is ‘’hot food’’ while curds is ‘’cold
food’’
Beet root builds blood..

76. Few Myths About Food…..
Colostrum is the stored milk of mother and
it is harmful..
Water should not be taken along with food
as it dilutes digestive juices and hampers
digestion..
Pure ghee is the most strengthening food..
Protein supplements(bournvita,horlicks
boost etc..) will boost health..
Athletes should take more of proteins than
carbohydrates