2. Lecture #3 MVS 110
Prof. Dr. Muhammad Shafique
MBBS, M.Phil, P.hD
3. Lecture #3 MVS 110
Overview
• Nutrients
i. Constituents of food
ii. Normal functions of body
• Macronutrients
Fats, Carbohydrates, Proteins
• Micronutrients
Vitamins & minerals
4. Lecture #3 MVS 110
Carbohydrates (CH2O)n
• Monosaccharides
1. Glucose
2. Fructose
3. Galactose
• Glucose
I. Used for energy directly
II. Stored as glycogen in muscle or liver
III. Converted to fat if taken in excess
Disaccharides
• Mono + Mono = Di = Simple sugars
• Lactose
• Maltose
• Sucrose
natural sugar - cane, brown, maple, honey
5. Lecture #3 MVS 110
Polysaccharides
• Plant and animal sources
• Plant
– Starch (complex CHO) - storage form of plant sugar; seeds,
grains, peas, beans, potatoes, roots
– Fiber - cellulose (structural part of plant); soluble and insoluble
types
Polysaccharides cont.
• Animal Polysaccharides
• Glycogen
– Storage polysaccharide
– 4oo g (1-2%) in resting muscle
– Serves as fuel reserve for ATP synthesis in muscle contraction
– 100 g (10% of liver wt)
6. Lecture #3 MVS 110
Role of CHO in Body
• Energy Source (4 kCal per g)
• Protein Sparer
• Metabolic Primer
– Primer for fat breakdown
• CNS fuel
– Brain, Nerves
• RBC, WBC
Glucose Conversions
• Glycogenesis
– Glycogen synthesis from glucose
• Gluconeogenesis
– Glucose synthesis from non-CHO sources
• Glycogenolysis
– Glucose synthesis from glycogen
7. Lecture #3 MVS 110
CHO Intake
• Acceptable range in adults
– 45 – 65 % of energy
– No less than 130 g/day
– No more than 25% of total calories from added sugars
• Fibre intake
– Men: 38 g/day
– Women: 20 - 35 g/day
– Water soluble are recommended (oats, bran, legumes, barley,
brown rice, peas, carrots, fruits
– Relationship to cancer and CHD
– CHO maintaining low glycemic index (fibres) should be added
to diet as compared to white bread having high glycemic index .
8. Lecture #3 MVS 110
Energy requirements in humans
• Daily average requirement
– 2000 – 2500 kcal/day
• Sedentary adults
– 30 kcal/kg/day
• Moderately active adults
– 35 kcal/kg/day
• Very active adults
– 40 kcal/kg/day
–Lipids (Fat)
• Simple lipid
• Triglyceride - storage form of fat
– Glycerol + 3 FFA
Saturated Vs
Unsaturated
9. Lecture #3 MVS 110
Saturated vs Unsaturated
• Saturated – (solid at room temp)
– Single bonds -holds as much H+ as possible
– Beef, lamb, chicken, egg yolk, dairy fats (milk, butter, cheese),
plant (coconut, palm oil, vegetable oil),
• Unsaturated - (liquid at room temp)
– Unsaturated with respect to H+
– Mono/poly unsaturated FFA
Compound Lipids
• Glycolipids
• Lipoproteins - transport of fat in blood
– HDL
– LDL
– VLDL
10. Lecture #3 MVS 110
Derived Lipids
• Cholesterol
– Not FA but same characteristics as a lipid
– Endogenous CHOL 700 mg/day
– Exogenous CHOL
– Plasma membranes
– Hormones
– Bile
– Sources (yolk, red meats, organ meats, shellfish, dairy
cream, butter.)
– Plants contain NO CHOL
11. Lecture #3 MVS 110
Role of Lipids
• Energy reserve
– 9 kCal per g
• Protection-Insulation
• Vitamin carrier (ADEK)
Lipids: Recommended Intake
• Fat: 20-35% of energy
– n-6 PUFA 5-10%
– n-3 PUFA 0.6-1.2%
• ~ 10% of the total fat can come from longer
chain , n-3 or n-6 fatty acids.
12. Lecture #3 MVS 110
Proteins
• Amino Acids
– 20 different AA required by body
• Essential v Non essential
– 9 AA cannot be synthesized in body - they
must be consumed- they are essential
– Histidine; Lysine; Methionine; Threonine;
Phenylalaine; Leucine; Isoleucine; Valine;
Tryptophan
13. Lecture #3 MVS 110
Protein Rating
• Biological Value - completeness for
supplying Essential AA
• Complete proteins - obtained by combining
foods (beans and rice; peas and corn; bread
and lentils; cereal and milk)
– Rating of protein:
• Eggs = 100 Dry beans = 34
• Fish = 70 Lean beef = 69
14. Lecture #3 MVS 110
1. Biological value/NPU
It is equal to :
Weight increase ( in gm)
________________________________ × 100
Grams of protein Consumed
2. Protein efficiency ratio/PER
It is equal to :
Grams protein digested and assimilated
________________________________ × 100
Grams protein taken in diet
Fish = 88% Milk = 84% Egg = 82% Meat = 74% Wheat =69%
3. Chemical Score
Defined as the ratio between the content of the most limiting amino acid in the test
protein to the content of the same amino acid in egg protein expressed as a %.
Egg protein= 100, milk proteins=65, meat= 70, fish= 60, wheat= 42
15. Lecture #3 MVS 110
Consequences of protein deficiency
• Retarded growth (child).
• Reduced weight (adult).
• Delayed wound healing.
• Anemia & edema.
• Fatty liver & cirrhosis.
• Hypoproteinemia.
PROTEIN ENERGY MALNUTRITION(PEM/PCM)
• Kwashiorkor.
• Marasmus.
• Marasmic kwashiorkor.
Role of Proteins in Body
• 12-15% of body mass
• Hb
• RNA, DNA
• Growth
• Cell function
• RDA = 0.6 g per kg BM
• Percent of energy 10-20%
16. Marasmus
1. Result of starvation
2. Breast fed of malnourished mother.
3. Infants lower than 1yr.
4. Skin thin, wrinkled.
5. No edema.
6. Hair thin, lustreless & face look
little monkey.
7. Total s.protein & fractions reduced.
A:G ratio maintained.
8. Plasma lipids not much affected.
9. Fatty liver not common.
10. Hypoglycemia not common.
11. Prognosis good unless severe
complications.
Kwashiorkor
1. Very low protein diet
2. Artificially fed & weaned child.
3. Older children 2/3rd yr.
4. Hyperpigmentation,desquamated.
5. Pitting edema.
6. Depigmented hair alternate with
more pigmented hair (Flag sign).
7. Serum proteins always reduced,
A:G ratio usually reversed.
8. Cholesterol, TG & LDL decreased.
9. Fatty liver may be seen.
10. Hypoglycemia frequent.
11. Prognosis not so good.
Comparison B/W Marasmus & Kwashiorkor
17. Lecture #3 MVS 110
Vitamins
• 13 different vitamins
– Water soluble C, B complex
– Fat soluble - A, D, E, K
– No difference between natural and synthetic - buy the
cheapest
• Hypervitaminosis - be aware
• Antioxidant role of vitamins
– Oxidative stress; free radicals
– A, C, E, beta carotene (vit A precursor)
• Megavitamin effect?
18. Lecture #3 MVS 110
Minerals
• Major v minor minerals
– Major = sodium, potassium, calcium, phosphorus,
magnesium, sulfur, chlorine
– Minor = iron, zinc, copper, selenium, iodine, fluorine,
chromium
• Part of body structure
• Participate in metabolism (regulate)
• Provide structure for bones and teeth
• Enzymes
19. Lecture #3 MVS 110
Calcium
• Calcium, estrogen and exercise
– Osteoporosis
• 1200-1500 mg per day (5- 8 oz of milk)
• Exercise helps
• The Female Athlete Triad
– Disordered eating; osteoporosis; amenorrhea
Sodium, Potassium, Chlorine
• Electrolytes and fluid loss problem
– Need to replenish
• Sodium and hypertension
– Recommended intake = 0.5 - 1.5 teaspoons (1100- 3300 mg)
20. Lecture #3 MVS 110
Water
• 72% of total muscle mass
• Functions of water
– Transport
– Temperature regulation
– Diffusion
– Lubrication
– Structure
Water Balance
• Intake
– Food Heat Disorders
– Fluids heat syncope
– Metabolism heat exhaustion
• Output heat stroke
– Urine heat cramps
– Feces
– Skin
– Lungs
21. Lecture #3 MVS 110
NUTRITION IN PREGNANCY & LACTATION
Extra allowance of 300 C/day, total 40000 C.
Proteins requirements are increased i.e. extra 10 g/day for the
requirements of :
Hemoglobin synthesis.
Plasma proteins synthesis.
Tissue proteins formation
Iron requirement: extra dietary Fe allowance 10-15 mg/day.in the
form of iron rich foods/supplementation for hemopoiesis to
prevent HMA.
minerals: Ca, P vit.D should also be added as diet supplements
for growing fetal bones.
Vit.A: extra 25-30 ug added.
Vit.K: to be increased in diet to avoid bleeding tendencies during
& after delivery.
B-comlexes : to be added extra in diet to work as Co-enzymes, &
in nucleic acid, collagen synthesis in growing tissues.
22. Overweight / Obesity
Defined as that body wt. over 20%
above mean ideal body wt. or
above standard wt. of the people
of the same age, sex and race
Hazards of obesity:
Diabetes mellitus.
Cardiovascular disorders.
Liver disease.
Respiratory disorders.
Metabolic diseases (gout).
Skin & sexual disorders.
Gynecological disorders.
Surgical postoperative risks.
Susceptibility to accidents.
Causes of obesity:
Over eating/ over nutrition.
Genetic in origin.
Metabolic changes in obesity:
Impaired glucose tolerance.
Hyperinsulinemia.
Hypertriglyceridemia.
Hypercholesterolemia.
LPL activity increased in type-II D.M.
Obesity- hypoventilation syndrome.
Role of Leptin in obesity:
Leptin is produced by fat cells
Leptin level increased in obesity.
Leptin suppresses appetite.
Leptin fights obesity by burning fat in
cells.
Antiobesity vaccine
Recently vaccine introduced which reduces
weight in mice named as
Cytos antiobesity vaccine.
Scripp’s vaccine
23. Important Questions
1. Give role of proteins in nutrition.
2. What is BV/NPU. Give factors affecting it.
3. What is balance diet, how it is formulated?
4. Give qualities of balance diet & basic food groups.
5. What are conditions of PEM/PCM?
6. Dietary role of essential fatty acid in body.
7. Dietary role of carbohydrates in body.
8. Explain glycemic index (GI) & factors affecting GI.
9. Define obesity and give causes & clinical features.
10. What diet you will suggest to add or restrict to obese?
11. What metabolic changes occur in obesity and starvation?
12. What are BMI, anthropometry & how are they calculated?
13. Why proteins, Ca, Fe & B- complexes are supplemented to the pregnant
woman & lactating woman?
14. What basic things are kept in mind to calculate caloric requirements of
a person?
15. What general suggestion you will advised regarding good nutrition?
16. A person consuming 2000kcals/day with on mixed food with diet-
induced thermojances is of 6%,then how many kcals he should ingest
to compensate for the loss of 6% in the form of body heat loss.
17. Calculate SDA if it is 30% in pure protein taking for a person mentioned
in question no16.
24. Clinical Case Histories
A young computer operator aged 28yr daily takes 250 g CHO, 100 g fats, 85 g
proteins & plenty of water with NaCl salts. Calculate calories consumed by
him per day.
A young female medical student has a habit of taking a lot of starchy diet with extra
sufficient amount of proteins & lipids. She also consumes normal allowances of
minerals, vitamins & water. Her physical activity is limited. After 3- 5 yrs., she may
have tendency of:
a). kwashiorkor .b) Marasmus c) Obesity d) Sickle cell anemia
C. A young bachelor attends the Primary Health Care at KFU& complains the
doctor that his gums are painful& swollen and bleeds on brushing the teeth
in the morning. Wound healing also delays. He looks pale& anemic. The
doctor explains to him that he is suffering from vitamin C deficiency, the
disease called “SCURVY”. He prescribes tablets of vit.C (ascorbic acid) &
also advises to take diet-rich in this vitamin like citrus fruits & fresh
vegetables regularly because this vitamin is not synthesized in human body.
In your opinion, the defect lies in which of the following biochemical
processes that leads to the poor formation of collagen during the deficiency
of vitamin C:-
a). Conjugation b). Deamination c). Hydroxylation d). Carboxylation
e). Transamination
25. D. A three years old child was brought with the manifestations such as anemia, pitting
edema, hairs dry& thin, anorexia, poor growth, diarrhea& increased susceptibility
towards infections. This clinical syndrome was precipitated by weaning the child from
breast milk onto a starchy foods without milk, eggs& meat, concluding that the diet
was adequate in calories but very deficient in proteins. Guess that this child was
suffering from which one of the following diseases?
a). Marasmus b). Steatorrhoea c). Creatininuria d). Kawashiorkor e). Tyrosinemia
E. In simple goiter, the thyroid gland is enlarged with low levels of thyroid hormones and
high levels of TSH. This abnormality with this gland usually be correlated with the
deficiency of which one of the following minerals?
a). Iron b). Copper c). Sodium d). Iodine e). Calcium
F. A patient has a genetic defect resulting in a deficiency of lipoprotein lipase enzyme.
After eating a meal containing a large amount of fat, one would expect to see a
plasma elevation of
a) VLDL b) LDLs c) HDLs d) Chylomicrons
G. A Hasawy young boy has a genetic defect resulting in a deficiency of "Lipoprotein
Lipase" . After eating a meal containing a large amount of fats and fat products ; one
would expect to see a plasma elevation of :
a). Chylomicrons b). VLD c). LDL d). HDL
H. 8. Megaloblastic anemia is characterized by macrocytic anemia, irritability, forgetfulness,
neurological disturbances and mental illness. This disorder is due to the deficiency of
which one of the following vitamins:-
a) Riboflavin b) Nicotinamide c) Vitamin D e) Folic acid
26. I. A young black man entered his physician’s office complaining of
bloating and diarrhea. His eyes were sunken and the physician also
noted additional signs of dehydration. The patient’s temperature was
normal. He explained that the episodes had occurred following a
birthday party at which he had participated in an ice-cream eating
contest. The patient reported prior episodes of a similar nature
following ingestion of a significant amount of dairy products. This
clinical picture is most probably due to a deficiency in:
a) Sucrase b) Isomerase c) Lactase d) a-amylase
J. A young woman finds that every time she eats dairy products, she
feels highly uncomfortable. Her stomach becomes distended & she
has gas & frequent diarrhea. Her friend suggested that she try yogurt
to get calcium & she is able to tolerate that. These symptoms do not
appear when she eats food other than dairy products. Like many
adults, she is deficient in an enzyme required for carbohydrate
digestion. The most likely enzyme in which she is deficient is:-
a). α-amylase (ptyalin) b). β -galactosidase(lactase)
c). α-glucosidase(maltase) d). Sucrose-α-glucosidase(sucrase) e). α,
α-trehalase .
27. K. A young boy developed indigestion, diarrhea, flatulence after attending a birth day party
in which a lot of ice-cream and dairy products were offered. He also has a previous
history of such signs & symptoms after consuming milk& milk products. His eyes are
sunken with other signs of dehydration but temperature is normal. Laboratory
reported a deficiency of one of the disaccharidases. What could be the following
disorder :-
a).Her’s disease b)Andersen’s disease c).Lactose intolerance d).Galactosemia e).Diabetes
mellitus
L. Alcohol impairs both absorption and storage of folic acid (folate). Megaloblastic
erythropoiesis occurs because cells are arrested in the S phase. Since DNA synthesis
is inhibited in folate deficiency because tetrahydrofolate (FH4) is required:-
a). In synthesis of purine nucleotide & dTMP b).In conversion of homocystein to methionine c).For the
utilization of cobalamin (vit. B12) d).Because of all of the above e). Because of none of the above.
M. The neurological disturbances seen in Niemann-Pick disease are associated
with the accumulation in central nervous tissues of which one of the followings ?
a) Prostaglandins b) Gangliosides c) Cerebrosides d) Sphingomyeline
e) Phosphatidyl serine
M. A child was brought to a physician with clinical picture like poor growth, mental
retardation, progressive paralysis and dementia. Histological examination of the
nerves shows demyelination and nerve stain yellowish- brown with cresyl violet dye
(metachromasia). The enzyme aryl sulfatase A (ASA) was absent. The doctor
explained that it was a autosomal recessive disease and usually fatal in the first
decade. This type of the genetic disease includes which of the followings:
a). Gaucher’s disease b). Fabry’s disease c). Krabbe’s disease d). Tay-Sach’s disease
e). Metachromatic leukodystrophy
28. N. One of the characteristics of each of the sphingolipidoses is the absence or deficiency
of the specific catabolic enzyme activity. These enzymes degrade sphingolipids and are
acid hydrolases. These enzymes are normally localized in the:-
a) Glogi complex b). Lysosomes c). Mitochondria d). Cytosol
P. A patient represented with over weight and hypertriglyceridemia because of the high
concentrations of both chylomicrons and VLDL in his plasma. Leptin level was also
found to be elevated. LDL and HDL were almost within the normal limits. Which one of
the following enzymes deficiency would you expect?
a) LPL b) LCA c) CPK d). Phospholipase A2 e) Cholesterol ester hydrolase
P. Alcohol impairs both absorption and storage of folic acid (folate). Megaloblastic
erythropoiesis occurs because cells are arrested in the S phase. Since DNA synthesis is
inhibited in folate deficiency because tetrahydrofolate (FH4) is required:-
a) In synthesis of purine nucleotide & dTMP b) In conversion of homocystein to methionine
c) For the utilization of cobalamin (vit. B12) d) Because of all of the above e) Because of
none of the above.
Q. Hartnup disease is a genetic defect in an amino acid transport system. The specific
defect is in the neutral amino acid transporter in both intestinal& renal epithelial cells.
Clinical symptoms of the disease result from deficiency of essential amino acid&
nicotinamide. Specifically the deficiency of which one of the following amino acids is
predominated in this disease?
a). Glycine b). Alanine c). Tyrosine d). Aspartate e). Tryptophan
R. A young man suffered third degree burns over much of his body & is hospitalized in a
severe catabolic state. His weight was 140 lbs(64 kg). 3000 gms of solution containing
20 % glucose and 4.25% amino acids was infused per day to supply a adequate proteins
and calories requirements. The physician instructed the staff sister to infuse lipid
solution as well because:-
a). To supply fibers b). To supply cholesterol c). To supply essential fatty acids d). To supply
additional calories e). To improve palatability of the mixture
