Do You Know Your Fats?
ByDavid McEvoy
What is fat?
There are three classes of nutrients; proteins,
carbohydrates and fat, which is also known
as lipid. Fat’s function is to provide energy
for the body, and pound per pound it contains
more energy in the form of calories than protein
and carbohydrate. The three types of fat are
triglycerides, cholesterol and phospholipids.
Fat calories are mostly stored in
triglycerides. Fat does not just serve
as an energy provider but fulfils other
bodily functions - cholesterol and phospholipids
are components of cell membranes and sheaths
surrounding nerve cells, and cholesterol
is also vital for the production of hormones
(sex and adrenal hormones) as well as
bile acids.
What are fatty acids?
Fatty acids are chains of carbon atoms
linked by chemical bonds, with a methyl
group at one end and a carboxyl group
at the other. A methyl group is a cluster
of carbon and hydrogen atoms, while a
carboxyl group consists of carbon and
hydrogen plus oxygen atoms. The chains
come in different lengths, with short
chain fatty acids having less than six
carbons and long ones having 12 or more
There are either single or double chemical
bonds keeping the chain together - single
bonds have more hydrogen molecules around
them. These bonds determine whether a
fatty acid is saturated or unsaturated.
Fatty acids provide energy to organs
including the heart as well as muscles
- they are also building blocks for cell
membranes, and energy storage for the
body. Fatty acids are converted into triglycerides
if not used up as energy - these are molecules
comprising three fatty acids with a glycerol
compound ‘backbone’. They are stored in
the body as adipose fat tissue.
What are saturated fatty acids?
Saturated fatty acids only have single
chemical bonds, and fats containing them
are known as saturated fats. These occur
in high quantities in lard, butter, whole
milk, cream, eggs, red meat, chocolate
and solid shortenings. Too much saturated
fat in your diet can raise cholesterol
in the blood, as well as increasing the
risk of coronary artery disease.
What are monounsaturated fatty acids?
Where saturated fatty acids have a single
bond, monounsaturated fatty acids have
a double bond. Monounsaturated fats are
found in avocados, nuts and oils including
olive, peanut and canola oil. It is believed
by scientists that consuming a lot of
monounsaturated fats helps to lower LDL
cholesterol - ‘bad’ cholesterol - and
lower the risk of coronary heart disease.
This is especially the case when these
fats are used in place of saturated fats
and refined sugars.
What are polyunsaturated fatty acids?
Polyunsaturated fatty acids are distinguished
by the fact that they have more than one
double bond. You can find polyunsaturated
fats in high quantities in vegetable oils,
corn, soy and sunflower.
What are essential fatty acids?
Polyunsaturated fatty acids which the
body cannot produce on its own but that
it needs for metabolic function are known
as essential fatty acids. It is necessary
to eat foods containing essential fatty
acids to maintain metabolic function.
What are omega-3 fatty acids?
Omega 3 fatty acids are found in many
varieties of fish including salmon, halibut,
sardines, albacore, trout, herring, shrimp,
clams, tuna, catfish and cod. They are
essential polyunsaturated fatty acids
with a double bond in the third carbon
position from the methyl terminal (chain
end) - this position accounts for the
‘3’ in the description. You can also obtain
Omega 3 from walnuts, flaxseed oil, canola
oil and spinach.
What are omega-6 fatty acids?
As the name would suggest, Omega 6 fatty
acids have a double bond in the sixth
carbon position from the methyl group
- they can be found in corn, safflower,
sunflower, soybean and cottonseed oil.
What are the n-3 and n-6 fatty acids?
N3 is another name for Omega 3, while
N6 is another name for Omega 6.
What are trans fatty acids?
Known as trans fats, trans fatty acids
solidify liquid oils having been made
through hydrogenation. If you heat an
Omega 6 oil such as corn oil to a high
temperature, trans fats are created. Trans
fats increase the shelf life of oils and
can be found in some margarines as well
as vegetable shortenings, commercial pastries,
fried foods, crackers, cookies and other
snacks. Trans fats should not be consumed
to excess as they increase ‘bad’ cholesterol
or blood LDL cholesterol, while decreasing
HDL or ‘good’ cholesterol and raising
the risk of coronary heart disease.
CONCLUSION
Although it may not seem logical, fats
are a necessary part of a healthy diet
- it is important however to identify
which fats are beneficial to health and
which are detrimental to it. A good intake
of the correct balance of omega3 to omega6
essential fatty acids is vital to keep
the body healthy.
Copyright 2006 David McEvoy
About The Author
Dave McEvoy is an award winning personal
trainer with over 20 years experience;
he also runs a high quality health supplement
website. http://www.mind1st.co.uk.