Fat and Fats
Fat is the most dense caloric food because it yields nine calories per
gram. This is more than twice the calories in a gram of carbohydrates
and protein. So the more fat you have in your diet, the more likely you
are to take in more calories than you should and the more fat you'll deposit.
A calorie derived from fat is stored as fat more easily than from protein
or carbohydrate (1,2). A rather disadvantageous property of fat is that
it is quickly and easily absorbed by the body and most goes directly to
your waistline. This is because the conversion of dietary fat to body
fat is easy and costs little energy. Only about 3 per cent of the fat
calories are expended during the conversion. And once a fat cell is born
it cannot be eliminated.
Fortunately, it can be shrunk to almost nothing. That's why it is important
to take control of your body fat early by avoiding fatty products and
exercising and not allow any more fat cells to develop. Nevertheless,
today is better than tomorrow to take action, ...It is still not too late.
Disadvantageous in today's world, but our ancestors when food was scarce,
relied on fat sores to survive. In today's affluent society, the average
adult man carries enough fat to ride a bike from Melbourne to Cairns,
a distance of 2,000 miles. An 80 kg male with around 15% bodyfat, (which
is not that high), has enough fat to run 150 miles, with only 3% of that
acting as insulation. Your body's limiting energy source is always sugar
in the form of glycogen or stored carbohydrate, never fat.
It has been proven that people who eat fat, put on fat more easily compared
to others eating carbohydrates and proteins even though the total caloric
intake is the same (3,4). Also your body can only burn fat in the presence
of oxygen. It can take a while before fats can be utilised as energy because
the glucose in your blood and glycogen in your muscles are put to use
first. Remember, carbohydrate is the preferred fuel and glucose and glycogen
are derived from it.
However, don't get discouraged, I'm not saying fat is hard to burn. How
efficiently your body burn fat has a lot to do with your level of conditioning.
The more aerobically conditioned you are the more fat you are able to
burn (5). Aerobic exercise helps burn fat simply because it demands oxygen,
and remember fat only burns in its presence. In addition, it increases
the development of capillaries to muscles and myoglobin needed to transport
oxygen to them. So with improved blood flow and better oxygen carrying
ability, your body becomes more efficient at burning fat. Secondly, exercise
stimulates enzyme activity known as hormone sensitive lipase, which promotes
the breakdown of fat you use.
There are different types of fats; saturated fats, unsaturated and polyunsaturated.
Saturated fats, as it's name implies have all the carbon atoms saturated
with hydrogen atoms and therefore won't hold any more hydrogen. Unsaturated
fats, especially polyunsaturated, don't have all their bonds saturated
and therefore are able to link up with other substances in the body, thereby
making them more biologically active. This biological activity makes these
fats healthier and some, such as olive oil, are even heart healthy. Conversely,
saturated fats are virtually inert and their only biological role is to
be burned for energy. But since people have more fat on them, especially
in the Western world, than they'll ever use, there is little need for
Another type of fat is partially hydrogenated vegetable oil found in margarine
and shortening. These fats were once unsaturated and in liquid form but
they have been hydrogenated (by adding a hydrogen atoms) so that they
become solid at room temperature.
Saturated fats are difficult to avoid, but every conscious effort must
be made to eliminate them from your diet or at least minimize their intake.
Perhaps the major reason why saturated fat should be avoided is because
our liver manufactures blood cholesterol from saturated fat. So the more
you eat the more it makes. Excessive blood cholesterol is very dangerous,
yet easy to achieve. It blocks off arteries causing all sorts of trouble.
Saturated fats are usually solid at room temperature and come from animal
sources. Sources of high saturated fat content are red meat fat and butter
fat. Butter fat is found in milk, cheeses, ice cream and other products
made from milk. Other sources are tropical oils such as coconut oil, palm
oil, palm kernel oil and the cocoa fat found in chocolate.
Dairy sources are high in fat. For example a 250 ml glass of regular milk
contains 87 % water (0 calories), 3.8 % fat (69 calories) and 8% carbohydrates
(64 calories). That makes it more than 50 % fat. So always choose low
fat or nonfat milk and dairy products. Simply switching from full fat
to low fat will make an immense difference to your fat loss goals and
Polyunsaturated and monounsaturated fats are usually liquids at room temperature,
and come from sources such as nuts, seeds and vegetables. Monounsaturated
fats are found in olive oil, canola oil and peanut oil. These are the
fats that should be mostly used. Monounsaturated fats tend to have a protective
effect on blood cholesterol levels by lowering LDL (bad cholesterol) and
increasing HDL levels (good cholesterol).
Fat consumption should never be cut out entirely, even though that is
very hard to do in our society. Two fats are considered essential because
the body cannot manufacture them -linoleic acid and linolenic acid. The
best vegetable sources of these essential fats are flax or linseed oil.
These are needed for healthy cell membranes, nerves and arteries. They
keep your skin smooth and lubricated, protect your joints and assist in
the breakdown of cholesterol. They also help absorb the fat-soluble vitamins,
A, D, E and K. These essential fats are found in vegetables such as corn,
soybean, safflower, walnut oils, also in nuts, seeds and green leafy vegetables.
Cold water fish are also high in these essential fats.
Major sources of saturated (bad) fats are found in meats and whole milk
dairy products. In 1991, the Physicians Committee for Responsible Nutrition,
a Washington lobby group representing 3000 physicians, asked the US Dept.
of Agriculture (USDA) -the government authority on healthy eating, to
abandon the four food groups. They appealed to reclassify meats and dairy
products as "optional foods". Dr. T Collin Campbell, Professor
of Nutritional Biochemistry at Cornell University, presented evidence
which showed that excess intakes of meat and dairy products in America
are strongly linked with high rates of cancer, heart disease, obesity
Some fat fighting tips are to avoid whenever possible meats and dairy
products. Cut all visible fat off meat and peal away all skin. Chicken,
turkey and fish are the leaner meat sources. Dairy products are important
so choose low fat milk or non-fat milk. Avoid eating egg yolk as they
are high in cholesterol. And lastly avoid all processed foods such as
snack foods like chips, crackers, biscuits. Even though they look dry
they are so high in fat that most companies don't dare put the contents
on the label for fear of losing customers. For those that do, please read
the label, you'll be surprised to know that potato chips and other snacks
are around 50% fat and provide little or no fiber, which is extremely
important. Amongst the best snack choices are rice cakes and pretzels.
Most of the fat on you is dead weight that inhibits performance, making
you feel exhausted not to mention the ensuing health complications. Imagine
carrying around a 5kg back pack with you all day. Even though 5 kg is
substantial, most people can afford to lose way more than 5 kg. So invest
a little time now, get to your ideal weight and literally feel the energy
levels increase. Believe me, everyone I've helped always say ..."Its
worth the investment".
1.Wade, G. N. 1983. Physiology Behavior, 29: 710
2. Jen, K. L., et al. 1981. Physiology Behavior 72: 161
3. Wade, G. N. 1983. Physiology Behavior, 29: 710
4. Jen, K. L., et al. 1981. Physiology Behavior 72: 161
5. Ivy, J. L.; Costill, D. L.; Maxwell, B. D. 1980. Skeletal muscle determinants
of maximum aerobic power in man. European Journal of Applied Physiology