BIOCHEMISTRY

2. NUTRITION
Mrs. Sona Valsaraj
Lecturer
Department Of Biochemistry
MAHE INSTITUTE OF DENTAL SCIENCES & HOSPITAL
Chalakkara, P.O Palloor, Mahe – 673310
U.T. of Puducherry.ph:0490 2337765

3. Nutrition is the science of food
and the nutrients and other
substances contained in the
food.

4. Study of human nutrition can be divided into
3 areas.
 Ideal nutrition:
 Under nutrition:
 Over nutrition:
Nutrients are the necessary
constituents of food required by the
organism for growth and maintenance
of life. They can be classified in to
micronutrients and macro nutrients.

5. Macro nutrients – These include proteins, fats
and carbohydrates. They form the main bulk of
the food .Proteins ,fats and carbohydrates are
sometimes referred to as proximate principles.
They are oxidized in the body to yield energy,
which the body needs.

6. Although proteins provide energy ,their primary
function is to provide essential and nonessential
amino acids for building of body proteins. Fats,
particularly the vegetable oils, besides being
concentrated source of energy ,provide essential
fatty acids which have a vitamin like function in the
body.

7. Water is the solvent of the body and the transport
vehicle for distributing nutrients to the tissues.
Water ,although not a nutrients of course required to
replace the water lost in the urine breath and sweat.
Fiber is also not a nutrient but it is considered as a
necessary food component.

8. Micronutrients
Vitamins and minerals are called micronutrients. They
are called so because they are required in small
amounts which may vary from micrograms to several
grams. Vitamins and minerals do not supply energy
but they play an important role in the regulation of the
metabolic activity in the body and help in the
utilization of proximate principles. Minerals are also
used for the formation of body structure and skeleton.

9.  Calorific value :The energy content of food is
measured in calories.
 One calorie: is the amount of heat required
to raise the temperature of 1g of water
through 1degree Celsius.
 it is expressed in kcal (C) which is equal to
1000 calories.
 Calorie is a measurement of energy in a
bomb calorimeter.
Energy contents of foods

10. Caloric requirement of food:
Amount of heat energy obtained by burning of 1g of foodstuff in the presence of O₂ ( in a
bomb calorimeter).
It is the amount of heat obtained when 1g of substance is completely oxidised.
Energy = calorie in nutrition

11. Energy yield from nutrients:
Nutrient Calorific
value(kcal/g)
carbohydrates 4
fats 9
proteins 4
alcohol 7
When 1g of carbohydrate is oxidised in the body ,4 C
are formed. When 1g of protein is oxidised in the body
,4 C are formed. When 1g of fat is oxidised in the body
,9 C are formed.

12. Respiratory quotient: is defined as the ratio of volume
of co2 produced to the oxygen consumed at the
whole body.
RQ= Volume of CO2 produced
Volume of O2 utilized
 Douglas apparatus .
 RQ of carbohydrates = 1
 RQ of fats = 0.7
 RQ of proteins =0.8
 Mixed diet =0.82-0.85.

14. Fats have relatively low RQ ,since
they have low O2 content.

15. The chemical nature of protein is highly
variable, and this cannot be represented by
any formula. By indirect measurements the
RQ of protein is found to be around 0.8.

16. C linical importance
Acidosis - RQ ↑ (in acidosis co2 out put is greater than O2 consumption.)
Fever- RQ ↑( increased breathing & there by will wash out more CO2,hence co2 production increases.)
Alkalosis-RQ ↓ (Respiration is depressed &CO2 will be retained in the body,ie less co2 produced.)

17. • DM-RQ↓
(In advanced state of DM ,when little
carbohydrate is burning, energy is supplied by
the oxidation of fat.)
• Starvation -RQ↓(Here the subject has to live on
his own tissue)
• Severe exercise-RQ ↑

18. Significance :
• Determination of Metabolic rate
• Type of food used
• Calculation of energy output
•

19. Energy requirements of a normal person:
Man consumes energy to meet the fuel demands of the three ongoing processes in the body.
 Basal metabolic rate (BMR)
 Specific dynamic action(SDA)
 Energy expenditure for physical activities.

20. Basal metabolic rate:
 is the energy required by an awake individual during physical, emotional and digestive rest under
comfortable conditions of temp, pressure and humidity in the post absorptive state.( 12 to 18 hrs after
meal).
Or it is the minimum amount of energy required by the body to maintain life at complete physical and
mental rest in the post absorptive state.

21.  Resting metabolic rate(RMR): is the measure of energy
required to maintain life or vital functions. The subject is
awake and non fasting.
 RMR &BMR are sometimes used interchangeably but there are
some small differences
 RMR includes the thermal effect of substrate metabolism &
heightened metabolic activity due to prior physical or mental
activity.
 BMR is measured directly by heat evolved, or indirectly by the
volume of oxygen consumed and co2 evolved per unit time.

22. Measurement of BMR:
Benedict & Roth basal metabolism apparatus
(closed circuit device ) or by Douglas bag
method(open circuit device) is used .
 By Benedict-Roth method ,the volume of O2
consumed by the subject for a period of 2-6
minutes under basal condition is determined.
Let this be A liters for 6 minutes. The
standard calorific value for 1 liter O2
consumed is 4.825 Cal.
 Heat produced in 6 min=4.825A
 Heat produced in1Hr is 4.825 AX10

23. Since BMR is to be expressed as
C/sq. meter /hour, the energy out put per hour
obtained has to be divided by the surface area
of the individual.
Body surface area is calculated in man from
height, weight and a constant(71.84)using the
formula of Du Bois .
A=Wo.425 x H0.725x 71.84
Where A=area in sq.cm, H=height in cm &
w=weight in Kilograms
More conveniently ,in practice ,the
nomograms can be used for finding the
surface area for an individual if heights and
weights are known.

24. Factors effecting BMR :
 Age
 Sex
 Temperature
 Exercise
 Fever
 Thyroid hormones
 Diseased states

25. Normal value for BMR: Since it is affected by
body surface area, it is usually expressed in
calories per / square meter of body surface.
 Adult men: 34-37kcal/square meter of the
body surface/hour.
 Women : 30-35 kcal/square meter/hour.

26. Factors influencing BMR
BMR depends heavily on the relative amounts
of metabolically active tissues like muscles and
glands, and of less active tissues like adipose
tissues and bones.
The higher the proportion of metabolically
active tissue in the body, the greater is the
BMR.BMR also increases with body size because
of higher amounts of metabolically active
tissue in a large body.

27. BMR is directly proportional to body
surface area. Since much of basal
metabolism is for maintenance of body
temperature& since heat loss is
proportional to the surface area of the
body, the BMR is directly proportional to
the body surface.

28. AGE Infants & children have much higher BMR
per kilogram of body weight than adults.BMR
rises up to
1 ½ years of age & thenceforth declines up to
adolescence, the decline steeper in females
than in males. This is due to the fact that
children possess a greater surface area in
proportion to their body weight.
Exception- In newly born babies it is low, about 25C/sq
m/hr. In premature infants it is still lower.

29. BMR is higher in males than in females of
identical age. BMR is higher in man than in
woman mainly because of a higher
proportion of metabolically active tissue like
muscles and glands in the former than in the
latter.
Hormones : BMR rises by 20-60% in
hyperthyroidism and falls by 20-40 % in
hypothyroidism. Growth hormone also
increases BMR.

30. Starvation reduces BMR by lowering thyroid activity,
muscle tone, total cell population, heart rate and
urine secretion.
Pregnancy and lactation-Increases BMR
Environment –In cold climates BMR is
higher compared to warm climates.
Fever –The higher temperature during fever
enhances BMR.The BMR increases by about 12%
with the rise of 1degree C.This is due to the fact
that increased temperature stimulates the chemical
processes of the body and there by increases BMR.

31. Specific dynamic action(SDA):
Also called post prandial thermo genesis or diet induced
thermo genesis.
 The phenomenon of the extra heat production by the
body, over and above the calculated caloric value, when a
given food is metabolized by the body( thermogenic effect
of food).
 This is due to expenditure of energy for digestion and
absorption.

32.  This energy is trapped from previously available
energy, so the actual energy from the food is
lesser than that of theoretical calculation.
 This is considered as activation energy needed for
a chemical reaction.
To get the energy from the food we ingested ,we
must first consume some energy to digest, absorb
&transport the foods nutrients to the body cells.
This is called the thermogenic effect of food
because these process require energy and generate
heat.

33. Suppose a person takes 250g of carbohydrates,
this should produce 250x4=1000 k cal. But
before this energy is trapped ,about 10% of
energy is drawn from the reserves of the
body.Thus the net generation of energy is only
1000-100=900 kcal.
When a person is kept under basal conditions, except
she is fed with food,ie,the subject is not in the post
absorptive state ,his heat energy output is increased
beyond the BMR. Suppose an individual whose BMR is
1800kcal/day is fed with food equivalent to 1800k cal,
his /her heat energy output(measured in closed circuit
methid) is increased beyond the basal output of
1800kcal.This stimulant action of food on heat energy
production is known as thermogenic action of food or
SDA.

34. If a person wants to get 1000k cal ,he should
take food worth 1100 kcal.This additional
calories equivalent to SDA has to be added in
diet.
For e.g. When 25 g of protein whose caloric
value is 100kcal is ingested130 kcal heat is
released after the metabolism in the body. This
extra 30kcal (130-100=30kcal) is the SDA of
protein. Thus proteins can increase the heat
energy production by 30%.Similarly when
carbohydrate equivalent to 100 kcal is
ingested,105 kcal heat energy is liberated after
its metabolism in the body, whereas ingestion
of fat equivalent to 100 kcal results in 112kcal.

35. It is a common experience that during hot
weather following the consumption of a
protein rich meal, one feels hot & humid for a
while. On the other hand ,in cold weather the
same would provide a comfortable feeling.
The significance of SDA of protein is the
maintenance of body temperature in cold
climate.
Thus carbohydrates and fats can increase the
heat energy production by 5% and 15%
respectively.

36.  SDA for proteins: 30%
 SDA for lipids :15%
 SDA for carbohydrates: 5%
 SDA for mixed diet: an extra 10% calories
should be provided to account for the loss
of energy as SDA.
 (This is because presence of carbohydrates &
fats reduces the SDA of proteins.)
This means that for every 100g of protein
consumed, the energy available for doing
useful work is 30% less than the calculated
value.

37.  Physical activity: energy requirements depend
on the occupation , physical activity and life
style.
 Sedentary: +30% of BMR (should be added).
 Moderate: +40% of BMR
 Heavy: +50% of BMR
 Pregnancy: +300kcal/day
 Lactation: +500kcal/day.

38. Light /sedentary workers : office worker, doctor, teacher,
shopworkers,architects
Moderate : Students, farm workers, factory workers, house
wives without mechanical appliances
Heavy : Masons , Blacksmith , Rickshaw pullers , players ,
construction workers.
OCCUPATION & ENERGY REQUIRMENT
Daily caloric or energy requirement of body mainly
depends on physical activity of the person. Individuals
involved in different types of job therefore can be
divided into 3 groups on the nature &duration of
work.

39. Light /sedentary workers : office worker, doctor, teacher,
shopworkers,architects
Moderate : Students, farm workers, factory workers, house
wives without mechanical appliances
Heavy : Masons , Blacksmith , Rickshaw pullers , players ,
construction workers.
OCCUPATION & ENERGY REQUIREMENT
Daily caloric or energy requirement of body mainly
depends on physical activity of the person. Individuals
involved in different types of job therefore can be
divided into 3 groups on the nature &duration of
work.

40. PHYSCAL ACTIVITY V/S ENERGY REQUIRMENT
Energy requirements in kcal/hour
(over & above BMR)
• Eating - 28 kcal/hr
• Writing – 30 ,,
• Driving – 63 ,,
• Walking - 140 ,,
• Cycling - 175 ,,
• Running – 490 ,,
• Swimming –550 ,,

41. RECOMMENDED DAILY INTAKE OF
ENERGY
Infants up to 2 months of age -120C/Kg
Infants from 2-6 months- 110C/Kg
Infants from ½ to 1 year -100 C/Kg
Children 1 to 10 years -110to 2200C
Boys 10 to 18 years -2500 to 3000C
Girls 10 to 18 years -2250 to 2300

42. For BMR =24× 55 kg =1320 kcal
+ for activity =40% of BMR =528 kcal
Subtotal =1320+528 =1848 kcal
+need for SDA =1848× 10% =184 kcal
Total =1848+184 =2032 kcal
Rounded to
nearest multiple
of 50
=2050 kcal
Calculation for energy requirement for a 55kg person ,doing
moderate work
For easier calculation,BMR for an adult is
fixed as 24kcal/kg bodyweight /day

43.  Proximate principles of diet:
 Carbohydrates:
 Proteins:
 Fat:
More over required amounts of minerals and
vitamins are also to be provided.

44. Importance of carbohydrates:
Ideally carbohydrates may provide60-65% of
total calories:
 In addition to providing calories ,it also
provide dietary fibers.
 Dietary carbohydrates:
i. Available carbohydrates :
ii. Unavailable carbohydrates:

45. ENERGY-Glucose is the major source of fuel for most organs & tissues. Excess is converted to fat & stored.
- AS MUCOPOLYSACCHARIDE.
- REQUIRED FOR GLYCOPROTEIN , PROTEOGLYCANS
-BRAIN OBLIGATORYLY USES 150 GM/ DAY
-RBC –TOTALLY DEPENDENT ON GLUCOSE.
-ASSOCIATED WITH SATIATION

46. To some extend every body cell depends on
glucose. The cells of the nervous system & brain
almost exclusively use glucose for energy.
Simple carbohydrates are monosaccharides &
disaccharides
Complex carbohydrates (glycogen,starch,fibre)-
Foods rich in complex carbohydrates tend to be
low in fat &sugar & can therefore add bulk to
meals.
Glycogen is not a significant food source of
carbohydrate. However ,the body stores much of
its glucose as glycogen. Glycogen is released
when the body needs glucose for energy.

47. Grains are the richest food source of starch.
Some examples of starches are rice, corn
,barley,oats.When we eat the plants our body
hydrolyses the starch to glucose.
Fibers are different than starches in that they
cannot be broken down by the digestive system
therefore they provide little or no energy for the
body.
Fibers has been shown to protect against heart
disease and diabetes by lowering cholesterol
&glucose levels.
Fibers has also been shown to provide a feeling
of fullness & promote proper bowel function.
E.g. of good source of fiber are bran cereals,
kidney beans ,sweet potato and pears.

48. - Accelerated use of glucose in metabolism to
produce energy & to ↓ fat oxidation
-PROTEIN SPARING EFFECT-When enough
carbohydrates are present in the diet, the
amino acids are not used for yielding
energy.
-SYNTHESIS OF NADPH & PENTOSE SUGARS.
-LOW SDA – 5%

49.  The complex carbohydrates that are not
digested by human enzymes.
 Plant cell wall component -Cellulose, hemi
cellulose, pectin, lignin, gums and mucilage.
Plant food are the only source of
dietary fibre.It is found in vegetables ,fruits
and grains.
DIETARY FIBRES
Dietary fiber is the name given collectively to
indigestible carbohydrates present in food.

50. Water holding Capacity-The dietary fibers
have a property of holding water and swell
like sponge with a concomitant increase in
viscosity.Thus,fibre adds bulk to the diet &
increases transit time in gut(gastric
emptying time) due to high viscosity.
Physiological effects-Dietary fibers exert its
influence along the gastrointestinal tract from
ingestion to excretion.
Adsorption of organic molecules-The organic
molecules like bile acids ,neutral sterols,
carcinogens & toxic compounds can be
adsorbed on dietary fiber and facilitates its
excretion.

51. It increases stool bulk-The fiber absorbs water
and increases the bulk of the stool and helps
reduce the tendency towards constipation by
increasing bowel movements.
Hypoglycemic effect of fibre-Some gums
present in fenugreek seeds are most effective
in reducing blood sugar & cholesterol.
Hypocholesterolemic effect of fiber -Fiber has
cholesterol lowering effect.Fibre bind bile acids
and cholesterol, increasing their fecal
excretion,& thus decreasing plasma & tissue
cholesterol level.

52. High dietary fiber is associated with reduced
incidence of a number of diseases like
Coronary heart disease, colon
cancer,diabetes,diverticulosis,hemorrhoids(piles).
Adverse Effect of dietary fibre
Dietary fiber has some adverse effects
on nutrition. Dietary fibers bind some
mineral elements and prevents their
proper absorption.
Sources:fruits, leafy vegetables , whole wheat legumes , rice bran etc.

53. FIBRE CHEMICAL NATURE PHYSIOLOGICAL EFFECT
Cellulose Polymer of glucose Retains water in feces,
promotes peristalsis, ↑
bowel action
Hemi cellulose Pentoses, hexoses
&uronic acid
Retains water in feces
↑ bile acid excretion
Lignin Aromatic alcohols Antioxidant, ↑ bile acid
excretion,
hypocholesterolemic.
Pectins Absorbs water, slows
gastric emptying, binds
bile acids and ↑ their
excretion

54.  Importance of FAT:
-ENERGY
-SYNTHESIS OF ESSENTIAL FATTY ACIDS
-ABSORPTION OF ESSENTIAL FATTY ACIDS
(linoleic acid,linolenic)
-ABSORPTION OF fat soluble vitamins
-COMPONENT OF BIOLOGICAL
CELL MEMBRANE
-PG SYNTHESIS
-STEROID HORMONE SYNTHESIS
-THERMAL INSULATOR
-COMPONENT OF CNS
-SYNTHESIS OF VITAMIN D.


55. Functions of essential fatty acids:
 Structural components of biological
membrane
 Participate in transport and utilization of
cholesterol.
 Prevents fatty liver.
 Synthesis of prostaglandins.
 Maintain proper growth and reproduction.

56. Food item Cholesterol content (mg/100g)
Hens egg 300
Egg yolk 1330
Liver 300-600
Brain 2000
Butter 280
Ghee 310
Meat & fish 40-200
Milk 10
Cholesterol content of food items

57.  Fundamental basis of cell structure and
function.
 Proteins act as enzymes, hormones, blood
clotting factors, immunoglobulin, membrane
receptors etc.
 Essential amino acids.
Importance of proteins
Essential amino acids-Any amino acid that humans
cannot synthesize or are unable to synthesize in
adequate quantity is termed essential & rest of the
amino acids are called nonessential as they can be
synthesized in the body. An essential amino acid must
be provided in the diet. An absence of essential amino
acid from the diet impairs protein synthesis& generally
causes negative nitrogen balance.

58. Nitrogen balance
Protein requirements can be determined by measuring
the nitrogen balance. The state of protein nutrition can
be determined by measuring the dietary intake &output
of nitrogenous compounds from the body. Although
nucleic acid also contain nitrogen, protein is the major
dietary source of nitrogen &measurement of total
nitrogen intake gives a good estimate of protein intake.
The output of N from the body is mainly in
urea & smaller quantities in urine, undigested
protein in feces. Significant amount may be
lost in sweat & shed skin.

59. The difference between intake and output of
nitrogenous compounds is known as nitrogen
balance.Catabolism of amino acids leads to a
net loss of nitrogen from the body. This loss
must be compensated by the diet in order to
maintain a constant amount of body protein.
Three states can be defined
Nitrogen equilibrium- In normal healthy
adults there is nitrogen equilibrium, nitrogen
intake equals nitrogen excretion. In this
situation, the rate of body protein synthesis is
equal to the rate of degradation & there is no
change in the total body content of protein.

60. Positive nitrogen balance-In this the intake of
nitrogen is more than excretion. It shows
nitrogen is retained in the body, which means
that protein is laid down. In growing child ,a
pregnant woman or a person in recovery from
protein loss, the excretion of nitrogenous
compound is less than dietary intake & there is
net retention of nitrogen in the body as
protein.

61. Negative nitrogen balance-In this
,nitrogen output exceeds input, this
occurs during serious illness& major
injury & trauma, in advanced cancer, or
if intake of protein is inadequate to
meet requirements, there is net loss of
protein nitrogen from the body,E.g. In
kwashiorkor &marasmus.If the situation
is prolonged ,it will ultimately lead to
death.

62.  Positive nitrogen balance : Intake is higher
Growing children
Pregnant women
Convalescence
 Negative nitrogen balance : Output higher
Kwashiorkor
diabetes
Marasmus
Corticosteroids

63. Factors effecting nitrogen balance:
 Growth: During the period of active growth, a state of positive nitrogen balance exists.
 Hormones: Growth hormones, insulin and androgens promote positive nitrogen balance. Corticosteroids cause a negative nitrogen balance.
 Pregnancy: A pregnant woman will be in a state of positive nitrogen balance due to growth of fetus.
 Convalescence: A person convalescing after an illness or surgery will be in positive nitrogen balance, due to active regeneration of tissues.
 Acute illness: A negative nitrogen balance is seen in subjects immediately after surgery, trauma & burns.
 Chronic illness: Negative nitrogen balance
 Protein deficiency: Negative nitrogen balance. Prolonged starvation is another cause.

64. Protein Quality or nutritive value of
proteins
Proteins present in different foods vary in the nutritional
quality because of the difference in amino acid
composition. Dietary proteins are obtained from both
plant &animal sources. The proteins obtained from
animal sources,eg-meat,egg,milk,fish cheese,etc are of
higher quality, whereas plant proteins from legumes,
cereals& vegetables are of lower quality.

65. The quality of protein depends on the pattern of
essential amino acids it supplies. The best quality
protein is the one which provides essential amino
acid pattern very close to the pattern of tissue
proteins. Egg proteins, human milk proteins
satisfy these criteria and are classified as high
quality proteins &serve as reference protein for
defining the quality of other proteins

66. Assesment of nutritional values:
1. Biological value(BV) of protein:
2. Net protein utilization(NPU):
3. Net dietary protein value(NDPV):
4. Protein efficiency ratio(PER):
5. Limiting amino acids:
6. Mutual supplementation:
Nutritional values

67. Biological value of protein is defined as the
percentage of absorbed nitrogen retained
by the body and is calculated by
Biological value=Nitrogen retained
X 100
Nitrogen absorbed
The amount of nitrogen in the diet eaten and
in excreta of adult animals is measured and
the percentage of nitrogen retained by
animals out of nitrogen absorbed from the
diet is calculated.

68. BV: Nitrogen retained/nitrogen absorbed during
a specific interval×100.
NPU:(Net protein utilization) –is a better index
than BV to denote nutritional quality &
availability of proteins.
nitrogen retained by the body ×100
nitrogen intake.
NDPV-( net dietary protein value) assess both
quality and quantity of proteins.
NDPV=intake of N × 6.25 × NPU.

69. Measurement of BV in experimental animals:
 127mg of protein A was consumed in a day
and 4mg is recovered in feces and 24mg in
urine. Then
 Amount ingested=127mg
 Amount absorbed=127-4=123mg
 Amount retained=123-24=99mg
 BV=99/123×100=81%

70. Protein efficiency ratio:
It is the weight gain per gram of protein taken.
Chemical score: It is a measure of the concentration of each
essential amino acid in the test protein which is then
compared with a reference protein. It is calculated as
Number of mg of the limiting amino acid
/g of test protein × 100
Number mg of the same amino acid/g egg protein

71. Protein LAA Protein supplemented
Rice Lys, Thr Pulse proteins
Wheat Lys, Thr ,,
Gelatin Tryptophan Milk proteins
Tapioca Phe, Tyr Fish proteins
Bengal gram Cys,Met cereals
Limiting amino acids in proteins
Limiting amino acid is that which
limits the weight gain when a
protein is supplied to an animal.

72. Recommended protein allowances
Infants 2.4g/kg body wt/day
Children up to 10y 1.75g/kg body wt/day
Adolescent boys 1.6g/kg body wt/day
Adolescent girls 1.4gkg/body wt/day
Adult(m & w) 0.8 g/kg body wt/day
Pregnancy 2g/kg body wt/day
Lactation 2.5g/kg body wt/day

73. Source of
protein
BV NPU PER Chemical
score
Egg 90 91 4.5 100
Milk 84 75 3.0 65
Meat 80 76 2.8 70
Fish 85 72 3.0 60
Rice 64 57 2.0 60
Wheat 58 47 1.7 42
Bengal g 58 47 1.7 44
Ground n 54 45 1.7 44
Soya bean 64 54 2.0 57
Nutritive value of proteins

74. Recommended dietary allowance(RDA):
 The quantities of the nutrients to be provided
in the diet daily.
Factors effecting RDA:
 Age
 Sex

75. Nutrients RDA
Carbohydrates 400g
Fats 70g
Proteins 56g
Essential fatty acids 4g
Vit A 100ug
Vit D 5ug
Calcium 800mg
Iron 10mg
Thiamine 1.5mg
Recommended RDA for an adult man,70kg

76. Balanced diet:
 A diet is said to be balanced one, when it
includes proportionate quantities of food items
selected from different basic food groups so as
to supply the essential nutrients in complete
fulfillment of the requirements of the body.
A diet may be defined as the kinds of
food on which a person or group lives.

77. A balanced diet should be based on:
 Locally available foods
 Should be within the economic means of the people
 Should fit with the local food habits
 Diet should be easily digestible and palatable
 Should contain enough roughage materials

78. Balanced diet
SEDENTARY MODERATE HEAVY SEDENTARY MODERATE HEAVY
CEREALS 460 510 670 410 440 575
PULSES 40 50 60 40 45 50
LEAFY
VEG
40 40 40 100 100 100
OTHER
VEG
60 70 80 40 40 50
ROOTS&
TUBERS
50 60 80 50 50 60
MILK 150 200 250 100 150 200
OIL &
FAT
40 45 65 20 25 40
SUGAR 30 35 55 20 20 40
ADULT MAN (QUANTITY PER GRAM PER DAY) ADULT WOMAN

79. PREGNANCY
(g/day)
CALORIES
(kcal)
LACTATION
(g/day)
CALORIES
(kcal)
CEREALS 35 G 118 60 203
PULSES 15 52 30 105
MILK 100 83 100 83
FAT - - 10 9 0
SUGAR 10 40 10 40
TOTAL 293 C 521 C

80. PROTEIN ENERGY MALNUTRITION (PEM)- is the deficiency of
macronutrients (energy & proteins) in the diet.
 Deficient in : Calorie intake
Nutrient intake (protein)
 Types : Marasmus or nonedematous PEM
Kwashiorkor or edematous PEM
Nutritional disorders

81. Marasmus: to waste (Greek word)
Marasmus is a chronic condition resulting
from a deficiency of both protein & energy.
Marasmus occurs in famine areas when
infants are weaned from breast milk& given
inadequate bottle feedings of thin watery
gruels(liquid food) of native cereals or other
plant foods. These watery gruels are usually
deficient in both calories & proteins.
.

82. Marasmus is characterized by
• Growth retardation
• Anemia
• Fat & muscle wasting(severe loss of
subcutaneous fat)
• Severe loss of body fat & muscles results in
emaciated appearance.
• Starvation adaptations cause serum proteins
&electrolyte concentration to remain within
their normal range and do not show edema.

83.  Irritable
 Hungry and cries continuously
 Skin: thin, attached to bone, wrinkles
 Hair: thin & lusterless. Texture may be modified
but no dyspigmentation
No edema
 Anemia
 Weakness

84. Biochemical alterations:
 BMR: subnormal
 Serum proteins: not much reduced
 Total proteins:5-6g/dl
 Albumin: 2-3g/dl
 Fatty liver: not common
 Plasma lipids not much effected
Prognosis: good
 Recover well with adequate dietary treatment

85. Marasmic child

86. Kwashiorkor:
Refers to condition caused by severe protein deficiency
in individuals with an adequate energy intake.
 sickness of the deposed child
 Deficiency of proteins- the most limiting factor.
 Seen in artificial fed & weaned children
 Starchy diet after weaning(less proteins & low
Quality proteins)
Age: <5y
Not emaciated but looks blown up with edema

87.  Lethargic & apathetic
 Refuses to eat(anorexia)
 Skin: Dermatitis, patches of hyper pigmentation, exfoliation, ulceration in skin
 Hair: Dry, sparse, depigmented ( black,brown,white)
 Diarrhea
 Anemia
 Moon face

88. Biochemical alterations:
 BMR: decreased
 Serum proteins: decreased
 Albumin-<2g/dl
 A/G ratio- reversed frequently
 Fatty liver may be seen
 ↓ cholesterol, TG & lipoproteins
 Prognosis: Not good. Mortality is relatively high.

89. kwashiorkar

91. Marasmus Kwashiorkor
Tropics(starvation) Diet low in protein
Deficiency of Calorie and Proteins Protein
Age of onset Infants (below one year ) Children(1-5y)
Pre-diagnosing factors Pre-maturity Infectious diseases e.g.
diarrhoea,Measles
Causes Breast feed infants of
malnutritious mother,
Prolonged breast feeding
without supplementation.
Artificial feeding, weane
children, low quality
protein without milk or
egg.
Clinical features Retarded growth,
Grossly emaciated,
Diarrhea,
Vomiting,
No edema
Retarded growth,
Not emaciated
Apathy, anorexia
Edema
Hair Texture may be modified but
no dyspigmentation
Often sparse, straight a
silky,dyspigmentation-
greyish or reddish

92. Marasmus and kwashiorkar

93. References:
1)Text Book Of Biochemistry-DM Vasudevan 7th
edition
2)Text book of Biochemistry with Biomedical
Significance For Medical And Dental Students-
Prem Prakash Gupta
3.Textbook of Biochemistry for Dental students-
Shivananda Nayak B
4. Biochemistry by Pankaja Naik, Fifth Edition