Nutrition for nursing Dr. Fahad Aldhafiri

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Nutrition for nursing
Dr. Fahad Aldhafiri
lipids
• Lipids commonly referred to as fats, include
triglycerides (fats, oils), phospholipids and
sterols (e.g. cholesterol).
1. Triglycerides
• Account for about 98% of the lipids in foods.
• Major storage form fat in the body.
• An individual triglyceride molecule may contain one,
two, or three different types of fatty acids.
• Fatty acids are basically chains of carbon atoms with
hydrogen atoms attached (See the fig.). At one end of the
chain is a methyl group (CH3), and at the other end is an acid
group (COOH).
• Fatty acids vary in the length of their carbon chain and in the
degree of unsaturation.
Saturated and unsaturated fatty acids
• Saturated fatty acids: all the carbon atoms
have four single bonds with hydrogen atoms.
• Unsaturated: fatty acids does not have all the
hydrogen atoms so, one or more bonds form
between the carbon atoms.
Unsaturated fatty acids
• Are soft or liquid at the room temperature e.g.: oils.
• Are susceptible to rancidity when exposed to light and
oxygen.
• Include:
1. Monounsaturated fatty acids: (if one double bond exists
between 2 carbon atoms).
e.g. Canola, olive oil and peanut oils.
2. Polyunsaturated fatty acids: (if there is more than
one double bond between carbon atoms).
• Polyunsaturated fatty acids have 2 types:
• Omega- 6 Polyunsaturated fatty acids (in plant oils):
e.g. Safflower and sunflower oils
• Omega- 3 Polyunsaturated fatty acids (in fish oils):
e.g. Salmon
Saturated fatty acid
• Solid at room temperature.
• occur naturally in all most fat but are highest in
meats, dairy products.
• Raise LDL cholesterol in the blood.
Important note
• All food fats contain a mixture of saturated,
monounsaturated, and polyunsaturated fatty acids.
When applied to sources of fat in the diet,
“unsaturated” and “saturated” are not absolute
terms used to describe the only types of fatty acids
present (As shown in the fig. below).
Hydrogenated fats
• A process of adding hydrogen atoms to
unsaturated fatty acids (e.g. margarine) to
make them less susceptible to rancidity and to
stay fresher longer.
Bad fats
• Bad fat raise LDL-cholesterol, which is a major cause
of coronary heart disease.
• Saturated fat is commonly known as a “bad” fat. A
strong body of evidence shows that a high intake of
most saturated fatty acids is linked with high total
and low-density lipoprotein (LDL) cholesterol, which
are risk factors for cardiovascular disease.
• Unsaturated Fatty Acids: are commonly
known as “good fats” because they are linked
to lower blood cholesterol levels and thus a
reduced risk of cardiovascular disease when
they are eaten in place of saturated fats.
• Hydrogenated fats are bad because they are
more saturated than the oil from which they
are made.
2. cholesterol
• Cholesterol is a sterol, a waxy substance whose
carbon, hydrogen, and oxygen molecules are
arranged in a ring. Cholesterol occurs in the tissues
of all animals. It is found in all cell membranes and in
myelin. Brain and nerve cells are especially rich in
cholesterol.
• The body synthesizes bile acids, steroid hormones,
and vitamin D from cholesterol.
• Cholesterol is found exclusively in animals, with
organ meats (kidney, heart, liver and brain) and egg
yolks the richest sources.
Please, note that:
• The cholesterol in food is just cholesterol;
descriptions of “good” and “bad” cholesterol refer to
the lipoprotein packages that move cholesterol
through the blood
Digestion
Function of the fats
• Fat provides energy and it provides about 60% of the
body’s calorie needs.
• All fat, whether saturated or unsaturated, provides 9
cal/g.
• Fat has other important functions in the body. Fat
deposits insulate and cushion internal organs to
protect them from mechanical injury.
• Fat under the skin helps to regulate body
temperature by serving as a layer of insulation
against the cold.
• And dietary fat facilitates the absorption of the fatsoluble vitamins A, D, E, and K when consumed at
the same meal.
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