protien lecture & lipids 2024.pptx

Basic Nutrition
PROTEINS & LIPIDS
By :- Melese.S(Chem,B.Pharm,Msc , Ass.Professor, PhD©)
Jimma University
Institute of Health
Faculty of Public Health, Nutrition & Dietetics Department
January ,2024
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Melese.S

Objectives
• Describe disease associated with protein deficiency
• Discuss disease associated to PEM
• Describe the correlation b/n HIV/AIDS and whey proteins
• Discuss the public health importance of proteins and lipids
(macronutrients)
• Discuss disease associated to essential fatty acid deficiency and
their sources
• Describe the importance of cholesterol and disease associated
with abnormal metabolisms of fatty acid /lipids/
• Discuss disease associated with hydrogenation/partial
hydrogenation/ of oils and consumption of solidified oils
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What is Protein?
Protein: an energy-yielding nutrient composed of carbon,
hydrogen, oxygen, and nitrogen.
• Differs from carbohydrates and fats because of the presence of
nitrogen.
• The body has at least 30,000 types of protein, each with a
different job.
• The building blocks of all protein molecules are amino acids.

Proteins
• The name was derived before a century from a Late
Greek prōteios , “of the first importance”.
• Proteins are the second most abundant components of
the body
• Proteins are composed of carbon, hydrogen, oxygen and
nitrogen.
• The unique feature of proteins in terms of composition is
that 16% of their weight is nitrogen.
• They could also contain other elements like Sulphur,
Phosphorus, Iron and Cobalt.
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Proteins…
• The basis of protein structure is the amino acid, of which 22 have
been recognized as constituents of most proteins
• All Amino acids have amino group(NH2) and Carboxylic Group(COO2)
• But, they are differentiated by the remainder of the molecule
(R) as shown in the figure.
Those amino acids that cannot be synthesized in the body and
need to be taken from food are essential (indispensable) amino
acids.
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C
H
COOH
R
NH2
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• Note that all amino acids contain carboxylic acid groups
(-COOH), amino groups (-NH2), and substituent, or
replaceable, side chains (-R).
• The general structural formula for an amino acid is
shown in this figure.
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Cont..
• Absence Essential a.a.from the diet leads to poor growth
performance by a growing animal. Essential amino acids are
labelled by (**) sign in the following table .
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Selenocysteine
Pyrrolysine
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• Polymerized to form proteins
• Stabilize 3-D structure of proteins
• by forming H and disulfide bonds
• Presence of specific AAs at the active site of enzymes is
• vital for catalytic activity
• Some AAs (glucogenic)
• Cys and met are sources of S in the body
• C skeleton and N of AAs used for:
• the synthesis of purine and pyrimidine bases
• Gly and met help in the detoxification mechianisms
• Met can act as a methyl group donor
• in methylation reactions
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Functions of amino acids
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• Certain AAs give rise to biologically important derivatives:
– Glycine is a precursor for
– Heme of hemoglobin
– Creatine that acts as the mediator of energy in muscles
– Tyrosine is the precursor for
– A number of hormones
» Thyroxine, triiodothyronine, epinephrine and nor-epinephrine
– Skin pigment melanin
– Tryptophan can give rise to
– vitamin niacin
– the neurotransmitter, Serotonin.
– Histidine can be converted to
– the mediator of allergic reactions i.e. histamine
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Functions…(Cont’d)
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BCAAs
• Branched chain amino acids are comprised of
leucine, isoleucine, and valine.
• These three amino acids are responsible for
stimulating muscle protein synthesis, or the
muscle building process.
• Protein contains branched chain amino acids
however, supplementing with BCAAs
throughout the day, and/or around your
training(HIFT) schedule will provide more
muscle fuel and energy, to enhance your
performance and recovery.
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Protein in the Body
Protein in the Body
Muscle
Bone
Skin
Other: blood,
glands, nerve
tissue

Protein Supplementation
• Claims include:
–Improved muscle growth and
function
• Increased weight gain
• Increased lean muscle mass
• Increased strength/power
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Types of Protein
• Whey protein-fast absorbing, support
lean muscle, great post-workout
• Soy protein- low fat, low cholesterol,
and vegetarian source
• Hydrolyzed whey- digested and
absorbed faster then whey
• Whey isolate- low fat, low carb,
• Egg protein- high quality lactose-free
source (toned physique)
• Micellar casein- slow digesting great
before bed
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Leucine Content as an Additional Indicator of Protein Quality
• A animal study has shown that the leucine content of a meal
determines its capacity to maximally stimulate muscle protein
synthesis1
– Whey protein (higher leucine) activates protein
synthesis more than wheat protein (lower leucine)
• Human studies have shown that leucine-rich protein sources such as
wheyare better at stimulating muscle growth than sources with
less leucine, such as soy2,3
– For example, compared with soy protein, whey
promoted more muscle protein synthesis
• By 18% at rest (P = .067)
• By 31% following resistance exercise (P < .05)
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1. Norton LE, et al. J Nutr. 2009;139(6):1103-1109.
2. Hartman JW, et al. Am J Clin Nutr. 2007;86(2):373-381.
3. Tang JE, et al. J Appl Physiol. 2009;107(3):987-992.
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Milk is made of two proteins, casein and whey. Whey protein can be
separated from the casein in milk or formed as a by-product of cheese
making.
• Whey protein is considered a complete protein and contains all 9
essential amino acids and is low in lactose content.
• This Medical News Today information article includes information
on the composition of whey protein, its use in muscle building,
and its potential health benefits and increase lean mucsle.
• A study published in the journal Clinical and Investigative
Medicine found that whey protein helps reduce weight loss
among HIV-positive patients.
Reference -Bounous G, Baruchel S, Falutz J abd Gold P."Whey
proteins as a food supplement in HIV-seropositive individuals",
Clinical and Investigative Medicine. Clin Invest Med. 1993
Jun;16(3):204-9. Accessed October 11th 2013.
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Cont ….
• Research done in jimma university
• Lipid based nutritional supplements improved gain of weight,
lean body mass, and grip strength in patients with HIV
starting ART. Supplements containing whey were associated
with improved immune recovery.(BMJ. 2014; 348:
g3187.Published online 2014 May
15. doi: 10.1136/bmj.g3187)
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Composition: Whey protein is a mixture of the
following:
• Beta-lactoglobulin
• Alpha-lactalbumin
• Bovine serum albumin
• Immunoglobins
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Soy is a complete protein but why does it rank low?
• Soy is generally recognized as the best single plant-source food with a complete amino acid
profile.
• Why then did Soy, the top plant-source protein, rank only mid-scale below fish and beef?
• Soy is a low BV-protein, lacking a high volume of sulfur-containing amino acid methionine.
The sulfur containing amino acids (cysteine being the other one) are particularly important
for:
– protein synthesis/growth,
– proper immune system function, and
– the body's production of glutathione (GSH).
• GSH is one of the most important anti-oxidants found in the body and protects cells and
serves to detoxify a variety of harmful compounds such as hydrogen peroxide, carcinogens,
reactive oxygen species (ROS), and many others.
• In particular, GSH is partly responsible for keeping low density lipoproteins
(LDL) from oxidizing and clogging our arteries. Several studies have
shown soy protein to be inferior to whey for the production of GSH and
improvements in immunity.
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• Proteins are nutrients that help build and maintain body cells and
tissues.
Proteins are classified into two groups: complete and incomplete.
• Complete proteins contain amounts of all nine essential amino acids.
SOURCES INCLUDE:
*Fish, meat, poultry, eggs, milk, cheese, yogurt, and many soybean
products.
• Incomplete proteins lack one or more essential amino acids.
SOURCES INCLUDE:
*Beans, peas, nuts, and whole grains.
• Proteins have many functions:
- Help make new cells.
-Help make and repair tissues.
- Help make enzymes, hormones, and antibodies.
- Provide energy.
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The Function of Protein
• Build and maintain tissues
– Protein makes up about 18-20% of your body
– Is a necessary part of every cell (needed to form the structure of
muscles, organs, skin, blood, hair, nails and every other body part).
– Skeletal muscle accounts for more than half of body protein
• Make important compounds
– Body uses proteins to make enzymes, some hormones, and
antibodies (defend against infection and disease)
• Regulate mineral and fluid balance
– Proteins help carry the minerals sodium and potassium from one
side of cell walls to the other (keeps a balance of fluid inside and
outside the cell)

The Function of Protein
• Maintain acid-base balance
– Maintenance of the correct level of acidity of a body fluid
• Proteins in the blood act as chemical buffers (counteract an
excess of acid or base in a fluid)
• Carry vital substances
– Used to transport lipoproteins (protein linked with fat), iron,
and other nutrients, as well as oxygen, chromosomes, and
other bundles of protein to other parts of cells
• Provide energy
– Provides the cells with the energy they need to exist
• If carbs and fats are lacking, the body uses protein as an
energy source

WHY DO WE NEED PROTEIN TO SURVIVE ?
We need protein for:
Growth (especially important for children, teens, and
pregnant women)
10% - 35% of calories should come from protein, when
energy when carbohydrate is not available
Tissue repair
Immune function
Making essential hormones and enzymes
Preserving lean muscle mass
Synthesis of enzymes, hormones all antibodies
Control Fluid movement in the body
Buffer(PH control): Due to the carboxyl or acid group (-
COO) and amino or basic group (- NH2 )
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Protein in the Body
• When you consume protein food,
acids in the stomach start to denature
the proteins
• Once the proteins are broken down
into their simplest form the amino
acids are then carried in the blood
stream to the parts of the body they
are needed.

Classification of proteins
I. Based on chemical composition.
a)Simple protein - yield amino-acids upon complete
hydrolysis
E.g.: - albumin - in eggs, zein of corn
b. Compound/conjugated proteins
Protein + Non protein
E.g.: - Hgb (Protein + hem) - Blood
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Cont..
II. Based on Nutritional Value:- This classification depends
on the essential amino acids content of the protein.
a. Complete proteins: Contain all the essential amino acids
in the proportion that is required to support growth and
maintain tissues. E.g. Almost all animal proteins except
gelatine (lack two essential A.As.). They are denoted as
complete because they resemble body protein (Egg &
Milk).
b. Incomplete Proteins: This refers to proteins that do not
contain all essential amino acids in the proportion that is
required to maintain growth and tissue repair.
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III. Based on Conformation of the Protein: This refers to
the three dimensional shape of the protein in its natural state.
Based on this proteins are classified as:
a. Globular proteins
-Tightly folded poly peptide chain - spherical or globular shape
-Mostly soluble in water
E.g.: - Enzymes, antibodies, and many hormones, Hgb
b. Fibrous proteins
-Polypeptide chains arranged in parallel manner along an axis
-Tough & in soluble in water
E.g.: - Collagen of tendons & bone matrix
- Keratin of hair, skin, nails and
- Elastin of blood vessels
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IV. Based on their Chemical Structure
A. Primary structure: refers to the sequence of amino
acids in the polypeptide chain of proteins held by
peptide bond.
Eg. Ala---gyc---Phenala---histd---tyr---
trp
B. Secondary Structure: This refers to the folding of
the polypeptide chain upon itself resulting in
alpha helix (right twisted or left twisted) and or B-
pleated sheet. This structure is held strong by intra
molecular hydrogen bonding.
1. Alpha helices
OR
2. B-Pleated Sheath
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C. Tertiary Structure: -
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•This refers to the three dimensional arrangement of
the protein structure (whether it is folded upon itself
giving rise to globular proteins or whether its straight
chain of poly peptides resulting in fibrous protein).
•This structure is maintained by the sulphide bond.
Fibrous protein
Globular protein
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D. Quaternary structure- aggregation of individual globule
stabilized by electrostatic bonding eg. Hemoglobin
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Levels of structure in proteins
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• Is eating Raw Meat nutritionally beneficial?
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• When meat is cooked at a high temperature, it
can form harmful compounds.
Some of these include
 Heterocyclic Amines (HAs),
Polycyclic Aromatic Hydrocarbons (PAHs) and
Advanced Glycation End-Products (AGEs).
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Q.Does Red Meat Increase Your Risk of Cancer?
• There are many observational studies showing
that red meat consumption is associated with an
increased risk of cancer (Cho E1, Chen WY, Hunter DJ,
et al,2006 &Teresa Norat, Sheila Bingham, et al,2005)
 Red meat intake and risk of breast cancer among premenopausal women.
 Intake of fat, meat, and fiber in relation to risk of colon cancer in men.
• The main type of cancer that red meat is believed
to cause is colorectal cancer, the third most
commonly diagnosed cancer in the world.
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• There are some observational studies out there saying that red
meat is associated with a greater risk of cardiovascular disease,
diabetes and death. Red Meat Consumption and Mortality Results From
2 Prospective Cohort Studies (An Pan, PhD; Qi Sun, MD, et al 2012)
• If meat really raises your risk of cancer (which is yet to be
proven) then this may be the reason
I. Heterocyclic amines: Mutagens/carcinogens produced during cooking of
meat and fish.(Sugimura T1, Wakabayashi K, et al ,2004)
II. Genotoxicity of heat-processed foods.(Jägerstad M1, Skog K.2005)
III. Modern diets are largely heat-processed and as a result contain high levels of
advanced glycation end products (AGEs). Dietary advanced glycation end
products (dAGEs) are known to contribute to increased oxidant stress and
inflammation, which are linked to the recent epidemics of diabetes and
cardiovascular disease.(Jaime Uribarri, MD,Sandra Woodruff, et al , 2010)
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Soybean
• Soybean crops are also heavily sprayed with chemical
herbicides, such glyphosate, which a French team of
researchers have found to be carcinogenic.
• Soybeans -- even organically grown soybeans -- naturally
contain "antinutrients" such as saponins, soyatoxin,
phytates, trypsin inhibitors, goitrogens and
phytoestrogens.
• Traditional fermentation destroys these antinutrients,
which allows your body to enjoy soy's nutritional
benefits. mostly in the form of soymilk, tofu, TVP, and
soy infant formula.
• Extured or texturized vegetable protein (TVP), also known as textured soy
protein (TSP), soy meat, or soya chunks is a defatted soy flour product, a by-
product of extracting soybean oil.
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Unfermented soy has the following 10 adverse affects
on your body:
1. High Phytic Acid (Phytates): Reduces assimilation of calcium,
magnesium, copper, iron and zinc. Phytic acid in soy is not
neutralized by ordinary preparation methods such as soaking,
sprouting and long, slow cooking, but only with long fermentation.
High-phytate diets have caused growth problems in children.
2. Trypsin inhibitors: Interferes with protein digestion and may cause
pancreatic disorders. In test animals, trypsin inhibitors in soy caused
stunted growth.
3. Goitrogens: Potent agents that block your synthesis of thyroid
hormones and can cause hypothyroidism and thyroid cancer. In
infants, consumption of soy formula has been linked with
autoimmune thyroid disease. Goitrogens interfere with iodine
metabolism.
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Cont …
4. Phytoestrogens/Isoflavones: Plant compounds resembling
human estrogen can block your normal estrogen and disrupt
endocrine function, cause infertility, and increase your risk for
breast cancer.
5. Hemagglutinin: A clot-promoting substance that causes your red
blood cells to clump, making them unable to properly absorb and
distribute oxygen to your tissues.
6. Synthetic Vitamin D: Soy foods increase your body's vitamin D
requirement, which is why companies add synthetic vitamin D2
to soymilk (a toxic form of vitamin D).
7. Vitamin B12: Soy contains a compound resembling vitamin B12
that cannot be used by your body, so soy foods can actually
contribute to B12 deficiency, especially among vegans.
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Cont …
8. Protein Denaturing: Fragile proteins are denatured during high
temperature processing to make soy protein isolate and textured
vegetable protein (TVP). Chemical processing of soy protein
results in the formation of toxic lysinoalanine and highly
carcinogenic nitrosamines.
9. MSG(monosodium glutamate): Free glutamic acid, or MSG, is a
potent neurotoxin. MSG is formed during soy food processing,
plus additional MSG is often added to mask soy's unpleasant
taste.
10. Aluminum and Manganese: Soy foods contain high levels of
aluminum, which is toxic to your nervous system and kidneys,
and manganese, which wreaks havoc on your baby's immature
metabolic system.
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Cont …
• Soy's antinutrients are quite potent. Drinking just two glasses of soymilk daily
provides enough of these compounds to alter a woman's menstrual
cycle. But if you feed soy to your infant or child, these effects are magnified a
thousand-fold.
• Infants fed soy formula may have up to 20,000 times more
estrogen circulating through their bodies as those fed other
formulas. You should NEVER feed your infant a soy-based formula!
• In fact, infants fed soy formula take in an estimated five birth control pills'
worth of estrogen every day.
• As dangerous as unfermented soy is, fermented soy from organic soybeans is
a different story altogether and can be a beneficial part of your diet.
• Fermented soy is a great source of vitamin K2, and K2 (combined
with vitamin D) is essential in preventing osteoporosis,
cardiovascular disease, dementia, and various types of cancer.
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The Health Effects of Too Much Protein

Applications of Denaturation
Denaturation of protein
occurs when
• An egg is cooked.
• The skin is wiped with
alcohol.
• Heat is used to cauterize
blood vessels.
• Instruments are sterilized
in autoclaves.
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Denaturation
Denaturation involves
• The disruption of bonds in the secondary, tertiary and
quaternary protein structures.
• Heat and organic compounds that break apart H bonds
and disrupt hydrophobic interactions.
• Acids and bases that break H bonds between polar R
groups and disrupt ionic bonds.
• Heavy metal ions that react with S-S bonds to form
solids.
• Agitation such as whipping that stretches peptide
chains until bonds break.
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Denaturation of Proteins
• The tertiary structure of a globular protein is the result of many
intramolecular attractions that can be disrupted by a change of
the environment, causing the protein to become denatured
• Solubility is drastically decreased as in heating egg white, where
the albumins unfold and coagulate
• Enzymes also lose all catalytic activity when denatured
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Denaturation
Renaturation
Denatured protein
Normal protein
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Denature
What conditions can denature proteins?
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Denaturing agents
A.Physical factors
Temperature,pressure ,mechanical shear force,ultrasonic
vibration and ionizing radiation
 Causes the protien to lose its biological activity
B.Chemical factors
Acids,bases,organic solvents(ethanol,acetone
etc),detergents(cleaning agents),heavymetal
salts(Hg,Cu,Ba,Zn,Cd, etc)
 Causes the denaturation
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Summary
Low Biological Value
Foods
High Biological Value
Foods
Contain all essential amino acids Only contain some of the essential amino
acids
Called high biological value foods. Called low biological value foods.
Mostly found in dairy products e.g. meats,
fish, poultry, cheese, eggs, yogurt, and
milk) Seafood and soya beans are also
complete proteins
Mostly found in plant foods e.g. legumes,
grains (Wheat, Oats, Rice, Barley, Corn),
seeds and vegetables.
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Biological Value for Protein (BV):
* BV is : a measure for the ability of dietary protein to
provide the essential amino acids required for tissue
protein maintenance.
* Proteins of animal sources (meat, milk, eggs) have high
BV because they contain all the essential amino acids.
* Proteins from plant sources (wheat, corn, beans) have
low BV thus combination of more than one plant
protein is required (a vegetarian diet) to increase its BV.
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Factors affecting nitrogen equilibrium
Nitrogen intake = Nitrogen Excretion (nitrogen balance)
?
Positive Nitrogen balance
-Pregnancy
-Lactation
-Growth
-Recovery from Illness (Convalescent stage)
Negative Nitrogen balance
1. Starvation
2. Devastating illness
3. Protein energy malnutrition
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Nitrogen Balance
Definition: Nitrogen balance refers to the situation where nitrogen
intake from food is equal to nitrogen excretion.
• This occurs in a healthy non-growing adult person taking adequate
amount of energy from carbohydrates.
• In some situations Nitrogen excretion may be greater than
nitrogen intake, this is called negative nitrogen balance.
• Other situations where nitrogen excretion is less than nitrogen
intake from food are called positive nitrogen balance.
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Three states are known for NB:
a)Normal adult: will be in nitrogen equilibrium,
Losses = Intake
b)Positive Nitrogen balance:
Nitrogen intake more than losses (High formation of tissue
proteins) occurs in growing children, pregnancy,
lactation and convulascence.
C)Negative Nitrogen balance:
Nitrogen losses more than intake
occurs in:- (Low intake of proteins) in starvation, malnutrition, GIT
diseases
- (High loss of tissue proteins ) in wasting diseases like
burns, hemorrhage& kidney diseases with albuminurea
- (High breakdown of tissue proteins ) in D.M.,
Hyperthyroidism, fever, infection
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Nitrogen balance
Nitrogen balance Negative nitrogen
balance
Positive nitrogen
balance
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Protein Requirement for humans in Healthy and
Disease Conditions
The normal daily requirement of protein for
adults is 0.8 g/Kg body wt. day-1.
• That requirement is increased in healthy conditions:
during the periods of rapid growth,
pregnancy, lactation and adolescence.
• Protein requirement is increased in disease states:
illness, major trauma and surgery.
• RDA for protein should be reduced in:
hepatic failure and renal failure
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Protein Digestion
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Metabolism of Proteins
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Protein Digestion
Kreb’s Cycle
Co2+H2o +
Energy
Acetyl CoA
Glucose
Pyruvate
Glycolysis
Protein
Amino acid
Deamination
NH2
Urea Cycle
Carbon
Skeleton
Glucogenic Amino acids
Ketogenic aa
Glucgenic aa
Both ketogenic & glucogenic aa
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RDA
Category
AGE, yrs. Gram of protein/kg g/1000 kcal
INFANTS 0-0.5
0.5-1.0
2.2/per kg weight
2/ per kg weight
-
-
•For adults :
-in general intake of 0.8 gram of protein/kg
of body weight is adequate.
-Muscle building exercise 2gram/kg/day
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RDA
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Category Age in years Gram per day g/1000 kcal
CHILDREN 1-3
4-6
7-10
2.3
3.0
36
17.7
16.7
15.0
Male 11-14
15-18
19-22
23-50
51+
44
54
54
56
56
15.7
18.0
18.0
20.7
23.3
FEMALE 11-14
15-18
19-22
23-50
51+
44
48
46
46
46
18.3
22.9
21.9
23.0
25.6
PREGNANT
LACTATING
+30
+20
-
-
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Summary of
amino acid
catabolism.
Amino acids
are grouped
according to
their major
degradative
end product.
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Protein - Energy Malnutrition
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Diseases of Malnourishment
• Marasmus: progressive emaciation due to lack of protein
& calories preventing growth.
– Cause of 49% of the 10.4 million deaths occurring in
children younger than 5 years in developing countries.
• Kwashiorkor: lack of protein in diet, leading to failure of
neural development.
– “the sickness the older child gets when the next baby is
born”
– Characterized by bloated belly
• Chronic hunger: enough food to stay alive, but not be
productive
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PROTEIN ENERGY MALNUTRITION
It is a group of body depletion disorders which include
kwashiorkor, marasmus and marasmic kwashiorkor.
* KWASHIORKOR:
Mainly due to lack of protein intake
* MARASMUS:
Mainly due to lack of primarily calorie/energy intake
and secondarily protein intake.
* MARASMIC KWASHIORKOR:
• Children have both features of kwashiorkor and
marasmus.
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CONT…..
 MARASMUS:- Marasmus is more common in children below the age of
1 years.
Manifestation and signs of Marasmus
1. Severe growth retardation
2. Old man’s or monkey’s face
3. Extreme emaciation
4. loose and hanging skin folds over arms and buttocks
5. Absolute weakness
7. Slow metabolism
8. Muscle wasting including weakened heart muscles
9. Slow brain development, permanent impairing learning ability.
10. There is little or no fat under the skin to insulate against cold
Protein deficiency can also cause fatigue, insulin resistance, hair loss,
loss of hair pigment, loss of muscle mass, low body temperature,
hormonal irregulation, as well as skin elasticity. Severe protein
deficiency, encountered only in times of famine, is fatal, due to the lack
of material for the body to construct its own proteins.

Marasmus (low calories)
Ravenously
hungry
Gross
weight
loss &
no fat
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Marasmus
• Deficit in calories – “marasmus” comes from
Greek origin of word “to waste”
• Gross weight loss
• Hyper-alert and ravenously hungry
• Children have no subcutaneous fat or muscle
 eventually starve to death (immediate cause
often is pneumonia)
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• Mainly primarily calorie / energy deficiency and secondarily
protein deficiency
• It effects children less than one year.
• Mainly characterized by muscle wasting/ emaciated (skin &
bone) and monkey face / simian..
CAUSES:
1. Early weaning with very low calorie diet (rice water, gaggary
dilute milk)
2. Repeated infections. eg. communicable disease like diarrhea.
3. Ineffective weaning
Marasmus
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1. Wasting
2. Appetite
3. Poor growth
4. Alertness/irritable
5. Diarrhea
6. Anemia
7. Skin sores/wrinkles
8. Hair changes
Clinical features of marasmus
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Example of marasmus
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• The loss of flesh is obvious. so skin becomes
wrinkled
• The belly is contrast to the rest of the body
• Looks highly emaciated with all skin & bone appearance sunken eyes, prominent
ribs.
• Hence it is called wasting disease.
• The face has a characteristics simian (monkey like) appearance.
1. Wasting
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• The child has a good/increased appetite.
• Children violently suck their hands or clothing
or noises.
2. Appetite
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• Child becomes irritable.
• The child cries continuously due to extremely
weakness.
3. Alertness/ irritable
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* In all cases the Childs fails to grow properly
due to protein and energy deficiency.
* Weight will be found to be extremely low by normal
due to loss of muscle.
4. Poor growth
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• A marasmus child has frequent watery stools.
• Child gets dehydrated.
5. Diarrhea
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• There is no flaky pain dermatosis.
• Skin are wrinkled.
• There may be pressure sores over bony
prominence.
6. Skin sores/wrinkles
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• Hair are normal in child of marasmus.
• Marked change in texture than of color.
7. Hair change
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Marasmus – mechanism
• Energy intake is insufficient for body’s requirements
– body must draw on own stores
• Liver glycogen exhausted in a few hours – skeletal
muscle protein used via gluconeogenesis to maintain
adequate plasma glucose
• When near starvation is prolonged, fatty acids are
incompletely oxidized to ketone bodies, which can be
used by brain and other organs for energy
• High cortisol and growth hormone levels
 Mechanism is same as anorexia
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• Mainly protein deficiency
• It effects children more than one year.
• Mainly characterized by edema and moon face.
CAUSES:
1. Early weaning with low protein diet (starchy diet no
protein, milk)
2. Repeated infections. eg. communicable disease like
diarrhea.
3. Ineffective weaning
KWASHIORKOR
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CONT…..
Manifestation and signs of kwashiorkor:-
1. Odema
2. Moon face
3. Growth failure
4. mental changes
5. hair and skin changes
6. infection
7. Nutrient deficiency
8. Short supply of digestive enzymes, digestive tract lining deteriorates.
9. Blood protein is no longer synthesized, so the child become anemic.
10. Develop fatty liver, caused by lack of the protein carriers that
transport fat out of liver.
11. Antibodies to fight off invading bacteria are degraded due to which
child becomes more prone to infections.
12. Dysentry
13. Measles - which might make a healthy child sick for a week or two,
kills the kwashiorkar child within two or three days.

Kwashiorkor
Swollen
belly
Pellagra
Decreased
muscle
mass
Sparse
hair
Infection
Apathy
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1. Edema
2. Moon face
3. Skin changes / flaky paint
dermatitis
4. Hair changes
5. Fatty infiltration in liver
6. Diarrhea
7. Poor growth
8. Wasting
9. Anemia
10. Apathetic / lethargic
Clinical features of Kwashiorkor
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Kwashiorkor – mechanisms
• Occurs in reaction to emergency situations
(famine)
• Kwashiorkor more likely in areas where
cassava, yam, plantain, rice and maize are
staples, not wheat
• Increased carbohydrate intake with decreased
protein intake eventually leads to edema
(water) and fatty liver
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Kwashiorkor (low protein)
• Decreased muscle mass (failure to gain weight and of linear
growth)
• Swollen belly (edema and lipid build-up around the liver)
• Changes in skin pigment (pellagra); may lose pigment where
the skin has peeled away (desquamated) and the skin may
darken where it has been irritated or traumatized
• Hair lightens and thins, or becomes reddish and brittle.
• Increased infections and increased severity of normally mild
infection, diarrhea
• Apathy, lethargy, irritability
 Death does not occur from actual starvation but from
secondary infection
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Example of kwashiorkor
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• Accumulation of fluid causes
swelling
• Starts with a light swelling in
the feet and spread up to the
legs.
• Later hands and face also
swell.
Detection procedure:
• Pressing the skin with fingers.
• A depression can be seen at the
place where pressure is applied.
1. Edema
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• Puffy or swollen face because of accumulation
of fluid/edema or fatty tissue.
• Appears round like so called moon face.
2. Moon face
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• Characterized by extensive flaking and
pigmentation mostly in sun unexpected areas.
• The skin becomes thick and varnished.
• It gets peeled off.
• The skin lesion first occur in areas subject to
friction or pressure. eg The groin, behind the
kness, on the buttocks, and at the elbows.
• Darkly pigmented patches form and these
may peel rather like sun baked blistered paint.
• This has leading to the term peeling paint or
flaky paint dermatosis.
3. Flaky paint dermatosis / skin change
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• Hair of normal asian child is dark, black, coarse in
texture and reflects light.
• In kwashiorkor hair become –
- thin
- lack of luster
- dull and lifeless
- Easily pluckable without pain
- Change to raddish color
4. Hair change
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• Liver becomes enlarged
(hepatomegaly)
• Fatty liver has yellow greasy
appearance and is often enlarged
and swollen with fat.
• Fatty liver occurs when excess fat
accumulates inside liver cell.
• The healthy liver replaced with
fatty tissue.
• Cause: the liver burns fat less
efficiently resulting the liver to
enlarged.
5. Fatty infiltration in liver
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• Stools are frequently loose.
• Contain undigested particle of food.
• Have offensive smell
• Have watery and tinged with blood
6. Diarrhea
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• A child loses weight and fails to grow.
• Loss in weight is less severe than in marasmus.
• Weight loss and growth failure can not marked
due to edema.
7. Poor growth
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• Muscle wasting is present but not be evident because
of edema.
• Childs arm and legs are thin because of muscle
wasting.
8. Wasting
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Marasmus Kwashiorkor
Cause Inadequate intake of energy
with adequate protein intake
Inadequate intake of proteins with
adequate energy intake
Age and
food intake
• 1-3 year
• Mother’s milk is
supplemented with food
(cereals) deficient in
calories
• After weaning (at about 1 year)
• Diet mainly contains CHOs
Symptoms • Arrested growth
• Extreme muscle wasting
• Weakness
• Weight loss
• No edema or changes in
plasma proteins
• Edema
• Distended abdomen
• Diarrhea
• Dermatitis / thin hair
• Enlarged fatty liver
• Low plasma albumin

Marasmic kwashiorkor
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• Treat the associated infection.
• Provide energy and protein rich food.
• Proper educating the mother
• Provide protein & calorie : 2g/ kg BW/ day & 150
kcal/ kg BW/ day.
• .
Treatment
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• Mental development
– Lower IQ levels
– Poorer school performance
• Behaviors of recovered severely malnourished
children
– shy, isolated, withdrawn
– decreased attention span
– immature, emotionally unstable
– fewer peer relationships/reduced social skills
– played less/stayed nearer to mothers
Severe Malnutrition: Consequences
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Health Effects and Recommended Intakes of
Protein
• PEM
– Infections
• Lack of antibodies to fight infections
• Fever
• Fluid imbalances and dysentery
• Anemia
• Heart failure and possible death
– Rehabilitation
• Nutrition intervention must be cautious, slowly
increasing protein.
• Programs involving local people work better.
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Protein
• Health Effects of Protein
– Heart Disease
• Foods high in animal protein also tend to be
high in saturated fat.
• Homocysteine levels increase cardiac risks.
• Arginine may protect against cardiac risks.
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Homocysteine: Role in Atherogenesis
• Linked to pathophysiology of arteriosclerosis in 1969
• CVD patients have elevated levels of plasma
homocysteine
• May cause vascular damage to intimal cells
• Elevated levels linked to:
– genetic defects
– exposure to toxins
– diet
• Increased dietary intake of folate and vitamin B6 may reduce CVD
morbidity and mortality
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Q)How is a high homocysteine level harmful?
• High homocysteine levels in the blood can damage the lining
of the arteries.
• In addition, high homocysteine levels may make blood clot more
easily than it should.
• This can increase the risk of blood vessel blockages.
• A clot inside your blood vessel is called a thrombus.
• A thrombus can travel in the bloodstream and get stuck in your
lungs (called a pulmonary embolism), in your brain (which can
cause a stroke) or in your heart (which can cause a heart attack.)
• who have very high levels of homocysteine are at an
increased risk for coronary artery disease.
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What causes a high homocysteine level?
• Homocysteine is normally changed into other amino acids for use
by the body. If your homocysteine level is too high, you may not
be getting enough B vitamins to help your body use the
homocysteine.
• Most people who have a high homocysteine level don't get
enough folate (also called folic acid), vitamin B6 or vitamin B12
in their diet.
• Replacing these vitamins often helps return the homocysteine
level to normal.
• Other possible causes of a high homocysteine level include low
levels of thyroid hormone, kidney disease, psoriasis, some
medicines or when the condition runs in your family.
• How is the homocysteine level measured?
• Homocysteine is measured using a simple blood test.
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Q)How Arginine may protect against cardiac risks?
• Arginine, taurine and homocysteine are amino
acids which have been shown to affect the risk
factors of cardiovascular diseases in humans.
• Arginine and taurine may protect against
cardiovascular diseases while homocysteine may
be a risk factor for them.
• Both arginine and taurine seem to lower blood
pressure, homocysteine level ,arginine may also
inhibit atherogenesis, and taurine may have
antioxidant properties.
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How Much Protein Do You Need?
• Protein is not stored in the body
• Quantity depends on:
– Age
– Gender
– Body Size
– State of Health
• RDA is 52 grams/day for 14-18 year old
males, 46 g/day for females
– .85 grams of protein per kilogram of body weight
• 1 kg = 2.2 pounds
• 135#/2.2 = 61.3 kg x .85 g = 52 g of protein

Who needs more protein?
– Growing youth and teens
– Pregnant & Breast Feeding Women
– Teen & Adult Males
– Individuals with Lean Muscle
• Large, tall person in comparison to a small, short
person
– Ill and Injured People to build antibodies and
rebuild damaged tissue

Protein Needs
• Balanced Diet
– Focus on Carbohydrates: 60 – 65%
– Low end of Fats: 20 – 25%
– Remaining calories are adequate for Protein: 10 –
20%
• Avoid dehydration
• Consume low-fat sources of protein
• Use low-fat cooking methods: grilling, baking,
& poaching

Protein
– Cancer
• A high intake of animal protein is associated with
some cancers.
• Is the problem high protein intake or high fat
intake?
– Adult Bone Loss (Osteoporosis)
• High protein intake associated with increased
calcium excretion.
• Inadequate protein intake affects bone health also.
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Protein
– Weight Control
• High-protein foods are often high-fat foods.
• Protein at each meal provides satiety.
• Adequate protein, moderate fat and sufficient
carbohydrate better support weight loss.
– Kidney Disease
• High protein intake increases the work of the
kidneys.
• Does not seem to cause kidney disease
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Protein
• Recommended Intakes of Protein
– 10-35% energy intake
– Protein RDA
• 0.8 g/kg/day
• Assumptions
–People are healthy.
–Protein is mixed quality.
–The body will use protein efficiently.
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Protein
• Protein and Amino Acid Supplements
– Amino Acid Supplements are not beneficial and can
be harmful.
• Branched-chain amino acids provide little fuel and
can be toxic to the brain.
• Lysine appears safe in certain doses.
• Tryptophan has been used experimentally for
sleep and pain, but may result in a rare blood
disorder.
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Acceptable Macronutrient Distribution Range (AMDR)
• Adequate intake of macronutrients to prevent the risk of
disease
AMDR for adults:
CHOs: 45-65%
Proteins: 10-35%
Fats: 20-35%

Lipids
“Life is all about shaping new molecules from
old.”
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EXERCISE and ENERGY
(LONGER term energy)
After glycogen stores are used up the body begins to break down
________
That’s why aerobic exercise
must continue for longer than
20 minutes if you want to
lose weight!
FAT
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Definition
• Lipids :- are a heterogeneous group of compounds
composed of carbon Hydrogen and Oxygen, which
are insoluble in water but soluble in non-polar
solvents such as chloroform, ether and benzene.
• These solvents are commonly called as fat solvents.
Though this definition covers majority of the lipids,
certain lipids will not come under this definition. For
example derived lipids like fatty acids are relatively
soluble in water.
 Lipids serve as fuel molecules, signal molecules, and
components of membranes, hormones and
intracellular messengers.
 They are esters of long chain fatty acids and alcohols.
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Lipids…
Classification
Nutritionally important lipids are classified into 3 main
groups on the basis of their Chemical structure.
• Simple lipids - include fats and oils (Triglycerides)
• Compound lipids - includes Phospholipids, lipoprotein
• Derived lipid - includes fatty acids and sterols.
* Some authorities classify lipids as structural lipids
(Phospholipids), Metabolic lipids (fatty acids, lipoproteins and
sterols) and storage lipids (triglycerides).
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WHY DO WE NEED FAT TO SURVIVE?
Although fats have received a bad reputation for causing
weight gain, some fat is essential for survival.
We need this amount of fat for:
• Provides energy(20% - 35% of calories should come from
fat)
• Energy storage (fat is the most concentrated source of
energy)
• Serve as a vehicle for the absorption of lipid soluble
vitamins ( like vitamins A, D, E, K, and Carotenoids )
• Providing cushioning for the organs
• Providing taste, consistency, and stability to foods
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Why do we need Cont…
• Prostaglandin, cytokine synthesis
• Cell differentiation , growth and development
• Cell membrane structure, myelination
• Hormone synthesis
• Bile acid synthesis
• Provision of Essential Fatty Acids
*Humans cannot synthesize double bonds within the
last nine carbons of the methyl end (n) of any fatty
acid chain. Fatty acids with double bonds in those
locations must therefore come from the diet—and are
considered essential
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Fatty Acids
• Building blocks for triglycerides and phospholipids
• A chain of carbon and hydrogen atoms with a carboxyl
group at the alpha end and a methyl group at the omega
end
Figure 5.1
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A. Fatty Acids
Classification
1. Based on the Length of Carbon chain
a. Short chain - 2 - 4 carbon atoms (eg. Butyric
acid)
– Liquid at room temperature
b. Medium chain - 6-12 carbon atoms (Caprillic
acid)
c. Long chain - 14-18 carbon atoms (palmitic acid,
stearic acid)
– Most common type of fatty acid in foods
d. Extra long chain - more than 20 carbon atoms
(Arachidicacid)
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Structure and nomenclature of fatty acids
• Saturated FA - no C-C double bonds
• Unsaturated FA - at least one C-C double bond
• Monounsaturated FA - only one C-C double
bond
• Polyunsaturated FA - two or more C-C double
bonds
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Fatty Acids Vary in Degree of
Saturation
• Saturated fatty acids
– All the carbons on the fatty acid are bound to
hydrogen
– Usually more solid at room temperature
– Higher melting point
– More stable
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Fatty Acids Vary in Saturation
• Unsaturated fatty acids
– Some carbons form a double bond with each other
instead of binding to hydrogen
– Monounsaturated fatty acid (MUFA)
• Has one carbon to carbon (C=C) double bond
– Polyunsaturated fatty acid (PUFA)
• Has two or more carbon to carbon (C=C)double bonds
– More liquid at room temperature
– Lower melting point
– Less stable
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Saturated and Unsaturated Fatty Acids Help
Shape Foods
Figure 5.3
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Examples of Saturated FA and MUFA
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Table-A. Structure & Melting point of Naturally Occurring
Saturated Fatty Acids
Carbon atoms Chemical formula Systematic name Common name Mp’t
(°C)
12 12:0 CH3(CH2)10COOH n-dodecanoic Lauric 44
14 14:0 CH3(CH2)12COOH n-tetradecanoic Myristic 54
16 16:0 CH3(CH2)14COOH n-hexadecanoic Palmitic 63
18 18:0 CH3(CH2)16COOH n-octadecanoic Stearic 70
20 20:0 CH3(CH2)18COOH n-eicosanoic Arachidic 77
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Cont..
Monounsaturated FA: - Monounsaturated fatty acids contain
only one double bond between carbon atoms. The most
prevalent MUFA in the diet is oleic acid.
Polyunsaturated FA (PUFA):-
They have two or more double bonds between carbon atoms. In
omega 3– PUFA, the first double bond occurs 3 carbon atoms
from the methyl carbon.
Important omega-3 fatty acids in nutrition are:
• α-linolenic acid (ALA),
• eicosapentaenoic acid (EPA), and
• docosahexaenoic acid (DHA).
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136
EPA and DHA
Major examples of long chain Omega-3 fatty acids
EPA (20:5) DHA (22:6)
(Eicosapentaenoic Acid) (Docosahexaenoic Acid)
Lowers the level of cholesterol, cleans
blood vessels, prevents stroke and
irregularity of the heart
Maintains and improves human
memory and learning behavior
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Table-B. Structure & Melting Point of Naturally Occurring
Unsaturated Fatty Acids
Carbon atoms Chemical formula Common name Mp’t
(°C)
16 16:1; ω-6, Δ9 CH3(CH2)5CH = CH(CH2)7COOH Palmitoleic -0.5
18 18:1; ω-9, Δ9 CH3(CH2)7CH = CH(CH2)7COOH Oleic 13
18 18:2; ω-6, Δ9,12 CH3(CH2)4CH = CHCH2CH = CH(CH2)7COOH Linoleic -5
18 18:3; ω-3, Δ9,12,15
CH3CH2CH = CHCH2CH = CHCH2CH =
CH(CH2)7COOH
-Linolenic -11
20 20:4; ω-6, Δ5,8,11,14 CH3(CH2)4CH = CHCH2CH = CHCH2CH = CHCH2CH =
CH(CH2)7COOH
Arachidonic -50
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Essential fatty acids
• Humans cannot synthesize double bonds within the last nine
carbons of the methyl end (n) of any fatty acid chain.
• Fatty acids with double bonds in those locations must
therefore come from the diet—and are considered essential
• The two essential fatty acids are:
– Linoleic acid (omega 6 fatty acid)
– Alpha-linolenicacids (ALA) (Omega 3 fatty acid)
• Both are (poly) unsaturated
• Therefore, absolute requirements for fat in the diet applies
only to unsaturated fat
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The Essential Fatty Acids: Omega-3 and Omega-6
Figure 5.4
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• Omega 3
• Omega 6
• Omega 9
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Function of EFAs
• Formation of healthy cell membranes
• Proper development and functioning of the brain
and nervous system
• Production of hormone-like substances called
Eicosanoids
–Thromboxanes
–Leukotrienes
–Prostaglandins
Responsible for regulating blood pressure, blood
viscosity, vasoconstriction, immune and
inflammatory responses.
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Benefits of Omega-6s
Specifically, omega-6 fatty
acids with a high GLA
content may help to:
• Reduce inflammation of
rheumatoid arthritis
• Relieve the discomforts of
PMS, endometriosis, and
fibrocystic breasts.
• Reduce the symptoms of
eczema and psoriasis.
• Clear up acne and
rosacea.
• Prevent and improve
diabetic neuropathy.
• Excessive amounts of
omega-6 (PUFA) and a
very high omega-
6/omega-3 ratio has been
shown to promote the
pathogenesis of many
diseases:
-cardiovascular disease
-cancer
-Inflammatory and
autoimmune diseases
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Linoleic Acid (18:2 6) and -linolenic acid
(18:3 3) are essential fatty acids
• We can’t make linoleic acid or -linolenic acid because
we don’t have the enzymes to add double bonds towards
the methyl end of other fatty acids
• We require at least 7.5 grams/day of linoleic acid = 1-2%
of total calories = about 1 tablespoon of plant oil. The
requirements for -linolenic acid are currently unknown
• Without linoleic acid, we develop symptoms of essential
fatty acid deficiency
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Essential Fatty Acid Deficiency is uncommon
in the USA
• 10% of the fat stored in our bodies is linoleic acid.
It takes at least 100 days to exhaust the stored
linoleic acid.
• Seen in premature infants, malabsorption
syndromes, alcoholism, with long-term parenteral
nutrition and other rare conditions.
• Symptoms include: decreased growth, fatty liver,
dermatitis, pulmonary edema, sterility, kidney
and heart problems, reduced immunity, death.
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Recommendations for Omega-3 Fatty Acid Intake
American Heart Association Guidelines
Population
 Patients without coronary
heart disease (CHD)
 Patients with CHD
 Patients who need to lower
triglycerides (fats)
Recommendation
 Fatty fish twice a week
 Include oils and foods rich
in -linolenic acid
(flaxseed, canola and
soybean oils; flaxseed and
walnuts)
---------
 1 gm of EPA+DHA per
day from fatty fish
 EPA+DHA supplements
---------
 2 to 4 grams of
EPA+DHA per day

Sources
• Nuts
• Avocados
• Olives
• Soybeans
• Oils (sesame, cottonseed, corn oil)
•  Plasma cholesterol
•  LDL
•  HDL
Effects
Omega-6 Fatty acids

Sources
• Plants
• Fish oil containing docosahexaenoic
acid (DHA) and eicosapentaenoic acid
(EPA)
• Suppress cardiac arrhythmias
•  Serum triacylglycerols
•  Tendency to thrombosis
• Lower blood pressure
•  Risk of cardiovascular mortality
• Little effect on LDL or HDL levels
Effects
Omega-3 Fatty acids

Essential Fatty Acid Deficiency
Side Effects
• hemorrhagic
dermatitis
• skin atrophy
• scaly dermatitis
• dry skin
• weakness
• impaired vision
• tingling sensations
• mood swings
• edema
• high blood pressure
• high triglycerides
• hemorrhagic folliculitis
• hemotologic
disturbances (ex: sticky
platelets)
• immune and mental
deficiencies
• impaired growth
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153
Omega-3 and Omega-6 fatty acids in plant/seed oils
Linoleic Acid (Omega-6) Linolenic Acid (Omega-3)
Soybean (50-57%) Flaxseed (35-56%)
Safflower (67-83%) Soybean (5-10%)
Sunflower (48-74%) Canola (6-14%)
Corn (34-62%) Safflower Oil (0.1%)
Canola (16-25%) Walnut (13%)
Sesame (35-50%) Olive oil (0.2-1.5%)
(Values in % of total fatty acids)
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Linoleic acid is essential Omega 6 PUFA
Linoleic acid, and omega-6 FA is one of the PUFAs
commonly found in both animal and plant foods.
• Linoleic acid (18:2), the shortest chain omega-6 fatty
acid is an essential fatty acid.
• Arachidonic acid (20:4) is a physiologically significant n-
6 fatty acid and is the precursor for prostaglandins and
other physiologically active molecules.
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Arachidonic acid (20:4 6) is the ultimate
precursor for making eicosinoids
• Prostaglandins – immunity, inflammation, kidney
function, ovulation and conception, sleep, pain,
blood pressure.
• Thromboxanes – blood clotting
• Leukotrienes – inflammation
• Aspirin works by inhibiting the synthesis of
eicosinoids
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Prostaglandins
CO2H
• originally isolated from semen and thought to be produced only in the
prostate gland
• now known to be present in almost all animal tissues
• functions:
• smooth muscle contraction
• inhibition of platelet aggregation
• lowering of blood pressure
• induction of labor
• all based on the prostanoic acid structure:
Melese.S

Roles of eicosanoids
• Prostaglandin E2 - can cause constriction of blood
vessels
• Thromboxane A2 - involved in blood clot
formation
• Leukotriene D4 - mediator of smooth-muscle
contraction and bronchial constriction seen in
asthmatics
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Hydrogenation
• If an unsaturated vegetable fat is altered by adding
hydrogen atoms, which did not exist in nature, the fat
molecule is said to be "hydrogenated."
• Hydrogenation transforms the shape of a fatty acid to a
"trans" form.
• You can visualize this by imagining a boat-shaped
molecule being transformed to a chair-shaped molecule.
• This molecule does not occur in nature, and the body
has difficulty digesting it.
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Why do we hydrogenate oils?
• Hydrogenation makes oils less prone to
rancidity and makes them remain solid at higher
temperatures.
• This is used primarily in the making of
margarine, but partial hydrogenation also
increases the shelf life of vegetable oils.
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Hydrogenation
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Vegetable Oil
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Fats, Oils, and Fatty Acids
O
OH
OH
O
Ni(H2)
trans-fatty acid
Vegetable oils
(liquids at RT)
H2/Ni
("partially hydrogenate")
margarine and
other products
(solids at RT)
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Trans Fatty Acids Formed During Partial
Hydrogenation
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Trans Fatty Acids
 Unsaturated fatty acids, behaving more
like saturated fatty acids in the body
 increase serum LDL (but not HDL)
 risk of CVD
 Not found in plants (animals only)
 Formed during hydrogenation of liquid
vegetable oils
 Found in baked food: cookies, cakes,
deep-fried foods

Fatty Acids and Rancidity
• Rancidity: spoiling of fats through oxidation
– The more double bonds there are, the more
susceptible to oxidation and rancidity
PUFA > MUFA > Saturated fatty acids
• Ways to enhance stability of fatty acids and
reduce rancidity
– Adding antioxidants
– Limiting food exposure to oxygen, heat, and light
– Hydrogenation (partial or full)
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What is rancidity and why is it a problem?
 The process which causes a substance to become rancid,
that is, having a rank, unpleasant smell or taste. OR
the hydrolysis and/or autoxidation of fats into short-
chain aldehydes and ketones which are objectionable in
taste and odor.
 A. Foods that are high in lipids and might become rancid
include potato chips, peanut butter, crackers, and others.
 B. Light, oxygen, trace elements such as iron and zinc, salt,
water, bacteria, and molds are factors that speed up the
oxidation process.

Hydrogenation: Benefits and Risks
• Benefits of hydrogenation
– Makes food fats more stable, increasing shelf life
– Changes the texture of the fat
• Oils become more spreadable
• Changes the characteristics of baked goods
• Risks of hydrogenation
– Increases amount of trans fatty acids in foods with
partially hydrogenated oils
• Increases liver production of LDLs
• Decreases liver production of HDLs
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Fatty Acids and Triglycerides
• Degree of Unsaturation Revisited
– Hydrogenation
• Protects against oxidation therefore prolonging
shelf life
• Alters texture
– Trans-Fatty Acids
• Changed from cis to trans configuration and act like
saturated fats in the body
• Heart disease connection is being researched.
• Conjugated linoleic acid is a naturally occurring
trans fat that may be beneficial to health.
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Cont…
• This is the problem with margarine — it contains
hydrogenated, trans-fatty acids.
• Studies show this type of molecule to be more
associated with artery disease than the saturated
("hard") fat found in butter.
• hydrogenated fat also is commonly associated
with junk food: potato chips. cookies, etc. It is
very hard to digest and is strongly associated
with vascular disease.
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Good fats
Monounsaturated
Good fats
Polyunsaturated
Fats to limit*
Saturated fats
Worst food
Trans fats
Avocado
Nuts
Olives
Olive oil
Some seeds
Flax seed
Hemp seed
Some nuts
Salmon, sardines
Beans
Eggs
Fish oil
(they stay liquid in
colder temperatures
and contain lots of
omega-3-6)
Fatty meat parts
Red Meat
Diary
Butter
Dark chocolate
Tropical oils
(coconut, palm oil)
Margarine
French Fries
Potato chips
Crackers
Everything fried
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Major Food Sources of Trans Fat for American
Adults
Figure 5.23
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Portion of Figure 5.7
Triglycerides
• Three fatty acids connected to a glycerol
backbone
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Caution:
High levels in
the blood are
a risk factor
for heart
disease
Triglycerides
• Most common lipid both in foods and in the
body
• Make up about 95% of lipids found in foods
• Functions
– Add texture
– Add flavor to foods
– Make meats tender
– Energy storage in adipose tissue
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•SIMPLE LIPIDS
•Fats and oils are composed of 3 fatty acids each in ester linkage with a single glycerol
•Fats, Oils, and Fatty Acids
CH2
CH
CH2
O
C
O
R'
O C
O
R''
O C
O
R
CH2OH
CHOH
CH2OH
+
RCO2H
R'CO2H
R''CO2H
1) OH-
2) H3O+
a triglyceride
•animal fat
R’s more saturated
higher melting point
(solid at RT)
•vegetable oil
R’s more unsaturated
lower melting point
(liquid at RT)
glycerine
(glycerol) fatty acids
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What should we eat?
Solidified vegetable oils OR liquid
vegetable oils?
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Sterols
• More complex than phospholipids or triglycerides
– Four connecting rings of carbon and hydrogen
• Do not provide energy
• Cholesterol is the best known sterol; Not essential in
diet
– Part of cell membrane structure
– Used to make bile, steroid hormones, provitamin D
Phytosterols – major plant sterols
Figure 5.11
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Cholesterol:
 Is steroid
 Cholesterol is a type of fat, found in your blood. It is produced by your body
and also comes from the foods you eat (animal products). Cholesterol is
needed by your body to maintain the health of your cells. Too much
cholesterol leads to coronary artery disease. Your blood cholesterol level is
related to the foods you eat or to genetic conditions (passed down from other
generations of family members).
 Has important function in body:
 important part in membrane of cells, organs and tissues in the body
 is used to make hormones,
 forms acids that are needed to absorb nutrients from food.
Therefore, cholesterol deficiency is not good.
 Source: 70% synthesized in body,
30% from food (animal source as meat, eggs and dairy products)
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Dietary Cholesterol Is Not Essential
• The liver synthesizes cholesterol needed by the
body
– Liver synthesizes ~900 mg/d
– Liver decreases synthesis based on dietary intake to
some extent
– Any extra source of calories can be converted to
cholesterol by the liver, greatest effect from
• saturated fatty acids
• trans fatty acids
• To reduce the risk of cardiovascular disease,
dietary cholesterol intake should be limited to <
300 mg/day
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Cholesterol levels:
 High level associated with heart disease
 Good level: below 200 mg/dl (low risk of heart disease).
 Border line: 240mg/dl (if higher at high risk)
 Notes:
 Measuring blood cholesterol level not need fasting?
Cholesterol level is not affected by single meal but affected by long
term pattern of eating (change from high fat diet to low fat diet for
several weeks)
 Cholesterol level is elevated during pregnancy (till 6 weeks after delivery)
 Some drugs are known to increase cholesterol levels as anabolic
steroids, beta blockers, epinephrine, oral contraceptives and vitamin D.
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Dietary sources of Cholesterol
Type of Fat Main Source Effect on
Cholesterol levels
Monounsaturated Olives, olive oil, canola oil, peanut oil,
cashews, almonds, peanuts and most other
nuts; avocados
Lowers LDL, Raises
HDL
Polyunsaturated Corn, soybean, safflower and cottonseed
oil; fish
Lowers LDL, Raises
HDL
Saturated Whole milk, butter, cheese, and ice cream;
red meat; chocolate; coconuts, coconut
milk, coconut oil , egg yolks, chicken skin
Raises both LDL and
HDL
Trans Most margarines; vegetable shortening;
partially hydrogenated vegetable oil; deep-
fried chips; many fast foods; most
commercial baked goods
Raises LDL
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Food Sources of Cholesterol and Plant Sterols
• Cholesterol comes from animal foods only
• Phytosterols and stanols are plant sterols
– Lower LDL levels by competing with cholesterol for
absorption
– Are found in soybean oil, many fruits, vegetables,
legumes, sesame seeds, nuts, cereals, and other
plant foods
– Some food manufacturers are fortifying foods with
them to help lower cholesterol
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Normal ranges
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Total Serum Cholesterol
<200mg/dL = desired values
HDL Cholesterol
With HDL cholesterol the higher the better.
<40mg/dL for men and <50mg/dL for women = higher risk
40–50mg/dL for men and 50–60mg/dL for woman = normal
values
>60mg/dL is associated with some level of protection against heart
disease
LDL Cholesterol
With LDL cholesterol the lower the better.
<100mg/dL = optimal values
Triglycerides
With triglycerides the lower the better.
<150mg/dL = normal
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Lipoproteins
• These are compound lipids that contain both protein and
various types and amounts of lipids.
• They are 25-30 % proteins and the remaining as lipids.
• They are made mostly in the liver and are used to
transport water insoluble lipids throughout the blood
soluble fat protein complexes.
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Lipids in the Body
• Chylomicrons
• Very-Low-Density Lipoprotein
• Intermediate-Density Lipoprotein
• Low-Density Lipoprotein
• High-Density Lipoprotein
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The Ratio of Protein to Lipid Determines the
Density of the Lipoprotein
Figure 5.17
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189
Good, Bad, Ugly & Deadly
C
TG
B 100 + E +C
C
TG
B 100
C
T
G
A I, A II
HDL LDL
VLDL
C
TG
B 100+ (a)
Lp(a)
TG
GOOD BAD
UGLY DEADLY
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190
Normal Lipid Profile
• Total Cholesterol < 200
• TG ‘Ugly’ Lipid < 150
• ‘Bad’ Cholesterols LDL < 100
• HDL ‘Good’ cholesterol > 50
• VLDL is Ugly TG ÷ 5 < 30
• Lp(a) ‘Deadly’ cholesterol < 20
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Cont…
• Consumption of Saturated fats increases LDL level,
while= increases risk factor for CHD and other
chronic non communicable diseases
• Consumption of PUFAs and MUFAs increase the
level of HDL = Protective effect form CHD and
other chronic non communicable diseases
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– LDL Cholesterol is Bad Cholesterol only when
• cholesterol becomes deposited on the blood
vessel wall
–as part of repair of disrupted endothelial
lining due to endothelial dysfunction
–if the carrier LDL is oxidized
– LDL cholesterol is not all that bad
• Cholesterol is brought to tissues for further
metabolism
• Tissues need cholesterol
–for hormone synthesis
–to modulate membrane fluidity
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Roles of HDL Apoproteins
• Brings cholesterol from peripheral tissues
(including arteries) to the liver
– Removing cholesterol from arterial wall
– Inhibiting growth of new plaques
• Enhances stability of plaques and inhibits
plaque rupture
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• Provides cholesteryl esters to LDL
• Protects LDL-cholesterol from oxidation by
– acting as a good anti-oxidant when HDL attaches
to LDL
• Reduce expression of adhesion molecules on the
vascular endothelium
– Reduced adhesion of leukocytes (early phase of
atherogenesis),
– prevent formation of new plaques,
– maintain integrity vascular endothelium
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HDL
• HDL is a fraction of plasma lipoproteins
• It is composed of 50% protein, 25% phospholipid, 20%
cholesterol, and 5% triglycerides
• Evidence suggests that high-density lipoprotein (HDL)
cholesterol is cardioprotective.
• LDL-chol = [Total chol] - [HDL-chol] - ([TG]/2.2) where
all concentrations are given in mmol/L
• (note that if calculated using all concentrations in
mg/dL then the equation is [LDL-chol] = [Total chol] -
[HDL-chol] - ([TG]/5))
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ecto-
nucleotide
pyrophosphat
ase/phosphodi
esterase-
1 (ENPP1)
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Atherosclerotic Plaque
• Continued endothelial dysfunction (inflammatory
response)
• Accumulation of oxLDL in macrophages (= foam
cells)
• Migration and accumulation of:
– smooth muscle cells,
– additional WBC’s (macrophages, T-lymphocytes)
– Calcific deposits
– Change in extracellular proteins, fibrous tissue
formation
• High risk =  VLDL (TG)  LDL  HDL
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Atherosclerosis
Figure 5.24
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High LDL-Cholesterol is a Major
Culprit for Cardiovascular Risk
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Metabolism of Lipids
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ß
-Oxidation
Acetyl COA
Co2+H2o+Energy
Triglycerides
Glycerol Fatty acids
Liver (gluconeogenesis)
Brain & other glucose
dependent cells (glycolysis)
Pyruvate
Krebs cycle
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Digestion, Absorption, and Transport of Lipids
• Lipid Transport
– Health Implications
• Factors that lower LDL and raise HDL
–Weight control
–Replace saturated fat with monounsaturated
fat and polyunsaturated fat in the diet
–Soluble fibers
–Phytochemicals
–Moderate alcohol consumption
–Physical activity
• Genes influence lipoprotein activity.
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Lipid Digestion
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Enzymes
•Lingual lipase- Ebner’s + parotid Glands
•Gastric lipase
•Pancreatic lipase + Co-lipase
Other Chemicals
•Bile salts
•Cholcystokinin
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Bile salts Emulsify micelles
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Fat
Watery GI
juices
Fat
Fig. 5-14, p. 150
In the stomach, the
fat and watery GI
juices tend to
separate. The
enzymes in the GI
juices can’t get at
the fat.
When fat enters the
small intestine, the
gallbladder secretes
bile. Bile has an
affinity for both fat
and water, so it can
bring the fat into the
water.
Bile’s emulsifying
action converts large
fat globules into
small droplets that
repel each other.
After emulsification,
more fat is exposed
to the enzymes,
making fat digestion
more efficient.
Enzyme
Emulsified
fat
Bile
Enzymes
Stepped Art
Emulsified
fat
Emulsified
fat
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Absorption of Lipids
• Once the digestion of lipids is complete, they will be absorbed
through intestinal luminal cell membrane by simple diffusion.
• The fate thereafter depends upon the size of fatty acid.
• From the intestinal luminal cells, fatty acids with less than or
equal to 10 carbon atoms will be absorbed directly in to the
portal system as free fatty acids.
• Fatty acids with larger chains of carbon(>=12), will be re-esterified
to form tryglycerides, cholesterol will be re-esterfied into
cholestrol ester, coated with phospholipids and proteins and
form Chylomicronsjoint lyphatic systemblood circulation
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Lipid Absorption
• Short- and medium-chain fatty acids can be
absorbed directly into the portal circulation
 Glycerol and long-chain fatty acids are absorbed from
micelles in the intestinal lumen into the intestinal lining
cells
 Once in the intestinal lining cells
• Triglycerides are reformed
• The triglycerides combine with phospholipids, cholesterol
and protein to form chylomicrons
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Figure 5.15
Chylomicrons Facilitate Lipid Absorption
• Chylomicrons are too
large to be absorbed
directly into the
bloodstream
– Absorbed via the lacteal
and into the lymph
– Lymph later enters
blood stream through
thoracic duct near the
heart
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What Happens to the Lipids You Eat?
• Lipids from foods
– Fat, phospholipids, and sterols
• Emulsified by bile
• Fats are digested by lipase into
– Free fatty acids, glycerol, and monoglycerides
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Figure 5-11 Triglyceride
digestion in the GI Tract
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Abnormal accumulation of membrane lipids can cause
diseases
Symptoms of these
diseases include:
• Mental retardation
• Paralysis
• Blindness
• Early death
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Health Effects and Recommended Intakes
of Lipids
• High intakes of saturated fat and trans fat and
high blood LDL cholesterol are related to
increased risk for heart disease.
• Omega-3 fatty acids in the diet appear to have
a protective effect.
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Dietary/Lifestyle Prevention/Intervention of Heart
Disease
Maintain
Endothelial
Function
Platelet
Activity
Decrease LDL Increase
HDL
Increase
Antioxidants
 High Blood
Pressure
 -3 PUFAs
  -6 PUFA
 Saturated Fat  MUFA/ 
PUFA
 MUFA/
  -6 PUFA
 Homocysteine
B6, B12, Folic
Acid
 Phytochemicals  Cholesterol  -3 PUFAs
(fish)
Vegetables
Phytochemicals Aspirin  -3 oils (fish)  Exercise Fruits
Stop smoking  Fiber Stop smoking Stop smoking
 Trans Fats Body weight if
overweight
 Fiber
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of Lipids
• Health Effects of Lipids
– Blood lipid profile
• Reveals concentrations of lipids in the blood
• Desirable levels
– Total cholesterol < 200 mg/dL
– LDL cholesterol < 100 mg/dL
– HDL cholesterol ≥ 60 mg/dL
– Triglycerides < 150 mg/dL
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Know Your Lipid Profile
Total Cholesterol < 200 mg/dl
LDL-Cholesterol < 100 mg/dl
HDL-Cholesterol ≥ 60 mg/dl
Triglycerides < 150 mg/dl
Fasting Blood Level Ideal, Healthy Level
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Know Your Diabetes, Metabolic Risk
Blood Glucose < 110 mg/dl 110-125 mg/dl ≥ 126 mg/dl
2 hr GTT < 140 mg/dl 140-200 mg/dl > 200 mg/dl
Triglyceride < 150 mg/dl > 150 mg/dl
Typically
elevated
HDL ≥ 60 mg/dl
M < 40 mg/dl
F < 50 mg/dl
Typically low
Fasting Healthy Pre-Diabetes Diabetes
(Metabolic Syndrome)
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The Metabolic Syndrome
Abdominal Obesity
Men
Women
> 40 inch waist
> 35 inch waist
Triglycerides ≥ 150 mg/dL
HDL cholesterol
Men
Women
< 40 mg/dL
< 50 mg/dL
Blood Pressure ≥ 130/ 85 mm Hg
Fasting Blood Glucose 110-125 mg/dL
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Category Systolic (mm/Hg) Diastolic (mm/Hg)
Normal 120 or less 80 or less
High Normal 130-139 85-89
High Blood
Pressure
140 or more 90 or more
Know Your Blood Pressure
Strive for blood pressure of 120/80 or less
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of Lipids
– Heart Disease
• Elevated blood cholesterol is a risk factor for cardiovascular
disease.
• Cholesterol accumulates in the arteries, restricts blood flow
and raises blood pressure.
• Saturated fat in the diet raises blood cholesterol.
– Risks from Saturated Fats
• Saturated fat in the diet raises LDL cholesterol, which
increases risk of heart disease.
• Food sources include whole milk, cream, butter, cheese,
high-fat cuts of beef and pork, and coconut, palm and palm
kernel oils.
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of Lipids
– Risks from Trans Fats
• Trans-fatty acids in the diet increase LDL cholesterol and
decrease HDL cholesterol.
• Food sources include deep-fried foods using vegetable
shortening, cakes, cookies, doughnuts, pastry, crackers,
snack chips, margarine, imitation cheese, and meat and
dairy products.
• Debate over butter versus margarine
– Risks from Cholesterol
• Dietary cholesterol has less effect on blood cholesterol than
saturated fat and trans fat.
• Food sources of cholesterol include egg yolks, milk products,
meat, poultry and shellfish.
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of Lipids
– Benefits from Monounsaturated Fats and Polyunsaturated
Fats
• Replacing saturated fat and trans fat with monounsaturated
fat and polyunsaturated fat is the most effective dietary
strategy in preventing heart disease.
• Food sources of monounsaturated fat include olive, canola
and peanut oil and avocados.
• Food sources of polyunsaturated fat include vegetable oils
(safflower, sesame, soy, corn and sunflower), nuts and
seeds.
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of Lipids
– Benefits from Omega-3 Fats
• Beneficial effects in reducing risk of heart disease
and stroke
• Food sources include vegetable oils (canola,
soybean and flaxseed), walnuts and flaxseeds, and
fatty fish (mackerel, salmon, and sardines).
–Need to avoid fish with high levels of mercury
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of Lipids
– Balance Omega-6 and Omega-3 Intakes
• Eat more fish (2 3-oz. portions per week)
and less meat.
• Bake, broil or grill the fish.
• Functional foods are being developed.
• Supplements are not the answer.
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of Lipids
– Cancer
• Dietary fat has an association with risks for some
types of cancer, but it is not as strong as the link
to heart disease.
• Fat does not initiate cancer development but may
be a promoter once cancer has developed.
• Some types of cancer have a stronger relationship
to fat intake. Saturated fat from meat is
implicated.
– Obesity can be a consequence of high-fat, high-
kcalorie diets in excess of energy needs.
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of Lipids
• Recommended Intakes of Fat
– The DRI and the 2005 Dietary Guidelines recommend
fat at 20-35% of energy intake (400-700 kcalories of a
2,000-kcalorie diet).
– FDA recommends 10% of energy intake from
saturated, 30% of energy intake total fat
– 2005 Dietary Guidelines suggest choosing a diet low in
saturated fat and cholesterol and moderate in total
fat.
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of Lipids
• Recommended Intakes of Fat
–Daily Values
• 65 g fat based on 30% of 2000-kcal diet
• 20 g saturated fat based on 10% of 2000-kcal
diet
• 300 mg cholesterol
–USDA Food Guide considers saturated fats
discretionary kcalories.
–Too little fat can be detrimental to health.
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Factors Associated with CVD
• Dietary
1. Elevated levels of LDL
--More LDL around to potentially oxidize and
accumulate in artery wall
2. Low levels of HDL
--HDL carries cholesterol from artery walls back to the
liver
3. Low levels of antioxidant vitamins
--Vit. E, Vit. C, Beta-carotene
4. Low levels of other dietary antioxidants
--Phenolics, flavanoids, red wine, grape juice,
vegetables, fruits
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Factors Associated with CVD
• High blood pressure
• Damages the artery wall allowing LDL to enter the wall
more readily
Cigarette Smoking
• Cigarette smoke products are oxidants and can oxidize LDL
• Cigarette smoking compromises the body’s antioxidant
vitamin status, especially Vit. C
• Damages the artery wall
Activity Level
• Exercise is the most effective means of raising HDL levels
Obesity
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Homocysteine Levels
• Normal byproduct of certain metabolic pathways
• Normally metabolized to other products
• Elevated levels cause damage to artery walls = increased
the oxidation of LDL
• Elevated homocysteine levels are significantly correlated
with increased risk to heart disease.
• Vitamins B6, B12, and Folic acid normalize homocysteine
levels.
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Micro-nutrients Macronutrients
Requirements
Required in very minute quantities. Required in larger quantities.
Functions
Prevents diseases. Provides energy.
Consequences of Deficiency
Deficiency results in Anemia, Goiter, Scurvy, etc.
Deficiency results in Kwashiorkor, Marasmus,
Malnutrition, etc.
Consequences of Overconsumption
Overconsumption of Vitamins leads to liver and nerve
damage.
Overconsumption of macro-nutrients results in cardiovascular
diseases, diabetes, obesity, etc.
Concentration
Available in a minute concentration in the body, less than 1
mg/gm.
Available in high concentration in the body, equal to 1 mg or
1000 microgram.
Composition
Also called trace elements. Also known as major elements.
Types
Vitamins, minerals and trace elements. Carbohydrate, protein and fats.
Examples
Antioxidants, Minerals, and Vitamins are examples of macro-
nutrients.
Proteins, fibre, carbohydrates, and fats are examples of micro-
nutrients.
Sources
Are found in fruits, vegetables, eggs, fermented foods, green
leafy vegetables, etc.
Are found abundantly in cereals, fish, legumes, meat, nuts,
oilseeds, potatoes, yam, etc.
Advantages
Micro-nutrients contribute to body growth and disease
prevention.
Provides energy required for the metabolic system.

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