2. LIPIDS
Lipids are a group of organic compounds
that are insoluble in water
But soluble in alcohol, ether, chloroform,
and other fat solvents.
The major (95%) of dietary lipids
constitutes triglycerides (Fats and oils). 2
3. Fats are made of the elements carbon,
hydrogen, and oxygen in the form of one
glycerol molecule with one, two, or three
fatty acids attached.
Although fats contain the same elements
as CHO, they have proportionately less
oxygen and more hydrogen and carbon
atoms; because of this, they are higher in 3
4. generally lipids:
Are the form of stored energy in animals
Have high energy value 9 kcal/ per gram of
fat
Act as carriers for fat soluble vitamins.
Like carbohydrates contain C, H and O
They have Phosphorous and Nitrogen
Fats, oils, and fat like substance, because
of similar solubility are classified as lipids.
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5. generally …
Fats that are solid at room temperature
are called fats because they are
saturated.
Palatability, it gives good test and we can
consume more.
Fats serve as insulator, it prevents heat
loss from the body.
Lubricant, it lubricates the
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6. Classification of lipids
Nutritionally lipids are classified into 3 on
the basis of their chemical structure.
Simple lipids = Fats and oils
Compound lipid = Phospho-lipids and
lipoproteins
Derived lipids= fatty acids and sterols 6
7. Essential Fatty Acids help transport
nutrients and metabolites across the cell
membrane.
Essential Fatty Acids are also involved in
brain development.
Essential Fatty Acids are needed for the
synthesis of prostaglandin.
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8. LIPOPROTEIN
These are compound lipids that contain
both protein and various types and
amounts of lipids. They are made mostly
in the liver and are used to transport
water-soluble lipids.
Lipids are transported in the blood in the
form of lipoprotein (soluble fat protein
complexes). 8
9.
Lipoproteins are compound lipids that
serve to transport lipids and cholesterol
through the blood.
Elevated levels of certain types of
proteins are a high risk for the
development of atherosclerosis.
Based on their density the lipoproteins
are classified as VLDL, LDL, HDL, and
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10.
Low-density lipoprotein (LDL)
This is composed mainly of cholesterol.
LDL transports cholesterol from the liver
to the tissues.
High serum level of LDL greatly increases
the risk of atherosclerosis
Diets that are high in saturated fatty
acids are associated with elevation in LDL
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11. Cholesterol
Cholesterol is found only in animal products.
Plant foods, regardless of their fat content,
do not contain cholesterol.
Cholesterol is a fat like lipid that normally
occurs in the blood and all cell membranes.
It is a major part of brain and nerve tissues.
Cholesterol is necessary for normal body
functioning as structural material in the
body cells, and in
the production of bile, vitamin D and a
number of hormones including cortisone and
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12.
Very low density lipoprotein (VLDL)
Very –low density lipoproteins (VLDL):
contain primarily triglycerides with some
protein and cholesterol.
VLDL transport endogenous triglycerides
from the liver to the tissues.
High serum VLDL level may increase the
risk of artherosclerosis.
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13. High density lipoprotein
High- density lipoproteins (HDL); contain
primarily protein, with small amounts of
triglycerides and cholesterol.
HDL transport cholesterol from the tissues
to the liver to be metabolized.
High serum HDL levels are protective
against the development of
artherosclerosis.
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14. SOURCES OF FAT
Animal – Fish, butter, beef,
Plant - vegetable, fruit avocado, nuts,
margarine, cooking oils.
Fats that can be easily identified, such as
butter, oils, and the fat around meat, are
known as visible fats.
Invisible fats are hidden in foods that do
not appear to be "fatty," such as the fat
marbled throughout meat, fat in egg yolks,
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15. FUNCTIONS OF FAT
Because they supply 9 kcal/g, fats and
oils are the most concentrated source of
energy in the diet, providing more than
twice the fuel value of CHO and protein.
With the exception of the central nervous
system and erythrocytes, which normally
rely solely on glucose for energy,
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16. All body cells can directly oxidize fatty
acids to produce energy.
However, because fat metabolism is more
complicated than CHO metabolism, CHO is
generally the preferred fuel.
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17. It delays gastric emptying time.
Fat may remain in the stomach for 3-5
hours after a meal, providing a feeling of
fullness (satiety) and delaying the return
of hunger.
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18. In addition, the presence of fat in the
duodenum stimulates the release of a
hormone in the stomach that inhibits
hunger contractions.
The absorption of the fat-soluble
vitamins A, D, E, and K through the
intestinal mucosa depends on fat.
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