Reducing Body Fat
"Several
factors modify the level of body fat and body composition,
including gender, age, level of physical activity, and hormonal
status. “(Bray, 1998). However, nutrition is an extremely important
factor to be considered into a diet plan when trying to lose
weight or extra body fat.
Energy
and Daily Caloric Intake-
The
four nutrients that provide the sources of energy (Alcohol,
Carbohydrate, Protein, Fat) have very different energy values
and storage capacities in the body.
This means that as you eat foods containing these energy
sources they are used up by your body at far different rates
(fat has a very large storage capacity and is therefore used up
very slowly). It is
wise therefore to consume a balance of these energy sources and
in a combination that leads both to optimal nutritional intake
while simultaneously minimizing the storage of fat.
There are many viewpoints regarding the optimal diet and even
how best to calculate caloric intake.
Many different diets have been marketed and go in and out
of style… (low fat versus high fat, etc).
Since most of you already have a good idea of how many
calories you should be eating, this article will be directed to
how your calories should be distributed.
You should have a diet that distributes your calories
into effective percentages of protein, carbohydrates, and fat
for optimal nutrition. A
diet plan should typically consist of 18-20 % Protein, 50%
Carbohydrate and 25-30% Fat (These percentages work for most
people, but vary somewhat depending upon health status, and as
previously stated- are custom designed for you in my Personal
Diet Plans).
Protein-
What
is protein and why is it important? Protein contains nitrogen
and provides amino acids that are essential for building body
proteins. Protein is used to build muscle and maintain/repair
lean tissue, including muscle and body organs.
There
are nine essential amino acids: histidine (essential for
children), isoleucine, leucine, lysine, methionine,
phenylalanine, threonine, tryptophan, and valine. These amino
acids must be supplied by food; the body cannot make them. There
are also 12 nonessential amino acids, which are important, but
called nonessential because the body can make them from the
essential amino acids.
Proteins
come from plant and animal sources. Animal proteins more closely
match the amino acid composition of human proteins, however
people who do not consume animal foods can get all of the
protein needs from plant sources, (they just need a larger
amount of plant protein versus animal protein to fulfill the
body’s requirement for protein).
According
to the Food and Nutrition Board of the National Research Council
(who establish dietary recommendations for the population),
the body’s need for protein is met when protein intake is at
.8 grams of protein per kilogram of body weight. (Divide your
body weight in pounds by 2.2 to get the equivalent in kilogram
weight). This meets the needs of about 90% of the population of
adults. In general this translates to about 63 grams of protein
per day for men, and about 50 grams of protein per day for
women. But there are factors that will increase the need for
protein, two of them being very strenuous physical activity, and
reduced caloric intake.
Protein
needs increase for severally injured or seriously ill people,
and athletes. Athletes need
to pay special attention to their protein intake. However, the
typical diet consumed in industrialized countries already
contains more than enough protein to cover the needs of most
athletes and any additional protein above the body’s needs is
either used for energy or converted to body fat. A
typical diet should contain between 10-20% of calories as
protein. What athletes and others expending great amounts of
physical energy need are additional calories, (in the proper
balance of fat, protein, and carbohydrate, not just protein).
Why
then are high protein diets popular right now? In the past few
years, there has been a swing towards a fear/avoidance of
carbohydrates, and carbohydrates are being blamed for the
obesity problem. The option on low-carbohydrate diets is to
increase fat and/or protein in the diet to make up for a
low-carbohydrate intake. What’s wrong with this is that high
protein, high fat diets may severely limit sources of
carbohydrates that provide essential vitamins, minerals and
other protective factors against serious diseases such as
cancer, heart disease, and high blood pressure. And, at very low
levels of carbohydrate intake, the body produces ketones, which
is a potentially dangerous condition. Beside the dangers of a
very low carbohydrate intake, a high protein intake produces
waste products containing nitrogen that require a lot of water
to flush out of the body. Excess protein taxes the liver and
kidneys, and does nothing to increase muscle mass because the excess
that is not used for energy is converted to fat.
The
fact is, the body needs all of the nutrients that supply energy:
fats, proteins, and carbohydrates. Each have a unique purpose
and are essential in the right amounts, and taxing to the body
in the wrong amounts. Too
much of any of these nutrients will lead to an increase in body
fat!
Carbohydrates-
Carbohydrates
are the body’s primary source of energy, and are quickly and
easily converted to blood glucose, the body cells’ preferred
source of fuel. In particular, the brain must have glucose as a
source of energy. The brain will not use other sources of energy
except in the extreme case of starvation, in which ketone bodies
(from the breakdown of body fat) are used by the brain. The body
cannot store a large amount of carbohydrate; there is only a
short supply available as glycogen in the liver and muscle. Therefore,
carbohydrates must be supplied on a regular basis.
So, we
need a certain amount of carbohydrate to prevent ketosis, but
where does it come from? Carbohydrates include sugars, starches,
and fiber. Foods that contain mostly carbohydrate are grains,
cereals, beans, fruits, and vegetables. Sugar and flour are
forms of carbohydrate, so any food made with sugar (like soda
pop) or flour (breads, pasta, bakery goods, cookies, crackers,
etc.) are sources of carbohydrate as well.
Certainly,
it is very easy to eat too much carbohydrate: it is in so many
foods, and so available! An excess of calories from any
source (fat, protein, carbohydrate, or alcohol) will lead to
weight gain if you do not increase your activity to match the
excess food intake. For most people, the recommended
amount of carbohydrate in the diet is that at least one-half
of your total calories should be in the form of
carbohydrate. Certain people, such as those with high
triglyceride levels or diabetes have special concerns with
carbohydrates and fats and should follow a diet that addresses
those needs in particular upon the advice of their physician.
Choosing carbohydrates that also provide important vitamins,
minerals and other nutrients (such as vegetables, fruits, whole
grains), and limiting the “junk” carbohydrates to special
occasions will help with keeping carbohydrate intake in proper
perspective. Choosing carbohydrates that digest more slowly or
eating quickly digesting carbohydrates with other foods is
another consideration and has to do with the glycemic index,
which is addressed as a separate topic.
Fats-
Fats,
also called by their chemical name triglycerides, are an
essential part of the human diet. Beside being the most
concentrated source of energy, fats carry vitamins A,D, E, and
K. They are made of a combination of various fatty acids, which
give our foods their flavor.
One of them, called linoleic acid, is essential to ensure
the synthesis of major hormone-like substances, the normal
growth of cells, and the functioning of the nervous system.
Different Forms
Fats come in different forms according to the fatty acids they
contain. They are:
-
Saturated
(or hydrogenated, partially or totally):
these are hard at room
temperature and primarily from animal sources with the
exception of palm oil, coconut oil and cocoa butter,
vegetable fats, which are also highly saturated.
-
Polyunsaturated
(non-hydrogenated): these are liquid at room
temperature or when refrigerated. They are primarily from
vegetable sources, although fish and marine fats are
polyunsaturated also.
-
Monounsaturated:
these
are a particular class of unsaturated fats. Liquid at room
temperature, they become cloudy if refrigerated. Olive oil
is a monounsaturated fat.
Although
people talk about fat sources as being one of the above, the
fats we eat are a mixture of all three types, and they are
categorized according to the greatest percentage of fatty acids
that fall into one of these categories. So, for example, olive
oil may be mostly monounsaturated fat, but it contains a little
saturated and polyunsaturated fat as well.
Too
Much of a Good Thing
The
fat needed in your diet is dependent upon your specific goals
but should, as a general statement, be limited to 25-30 percent
of your daily intake.
Americans consumed 32% of their calories as fat in 1910.
They now consume 42% of their calories as fat. About half of
that fat is “visible,” (the stuff added to food like
margarine and salad dressings). Unfortunately the rest comes “hidden”
in many foods, often more difficult to control. Different fats
have been associated with public health problems:
Too
much fat, whether saturated or unsaturated, has been associated with the
development of cancers of the breast, uterus and prostate.
Too
much saturated fat
and fat raise
the levels of cholesterol and triglyceride in the blood. These
are risk factor for heart disease.
Too
many calories as a result of too much fat
leads to obesity, a risk factor for heart disease, diabetes,
cancer, joint problems, etc.
Polyunsaturated
fat lowers the level of blood cholesterol and triglyceride.
In
Summary –
Weight
management through reduction of excess body fat plays an
important role in maintaining good health and fighting disease.
Going too low or too high in carbohydrate, fat, or
protein for any extended period of time will compromise your
health and your fitness goals. There are definite minimums of
carbohydrate, fat, and protein that the human body needs in
relation to body size, age and physical stress, and the short
term results from some extreme diets can really compromise your
long term health status and fitness goals.
Putting these concepts into a “real” food diet, so
that you’re eating the right foods, in the right amounts for
your particular needs is what Personal Dietitian's Personal
diets can help you do.
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