NUTRITION

INTRODUCTION

For many years, receiving proper nutrition and maintaining a
specific weight was thought to be dependent upon choosing foods
from the basic 4 food groups - meat, dairy, fruits and vegetables,
and breads and cereals.  More recently, in light of estimates that
show that approximately 40$ of all Americans are overweight,
researchers have begun digging deeper into the realm of nutrition
and have discovered that we have only "scratched the surface" thus
far in our knowledge of the subject and its impact upon our lives.

The U.S. Senate Select Committee on Nutrition and Human Needs
declared in 1977 that Americans consume too much fat, especially
saturated fat, too much cholesterol, refined and processed sugars,
sodium, alcohol and calories, and not enough complex carbohydrate
and fiber.

Nutrition has undoubtedly become a science, but it is not necessary
to be a scientist in order to understand some of the basic facts of
nutrition.  The information included in this module should help you
become familiar with some basic nutrition principles and how those
principles can best help you in your pursuit of total wellness.

ENERGY NUTRIENTS

Our bodies need fuel to keep us going just as a car needs gas in
order to operate.  We must derive the fuel that our bodies need
from 3 basic nutrients: protein, carbohydrates, and fats.

Since protein constitutes more than 50% of the human body, it is
essential that protein be included in our diet.  Dietary protein is
broken down by the body into components called amino acids. 
Twenty-three of these amino acids are needed, and of these 23, 10
cannot be synthesized by the body and, therefore, must be included
in the diet.  These 10 are called essential amino acids and can be
found in protein foods such as meat, milk, eggs, cheese, poultry,
fish, and whole grain cereals.  Protein intake should constitute
between 10-15% of the total calories consumed per day.  The typical
American diet generally exceeds this amount by 2-3 times!  In this
case, more is  not better since the excess protein stands a good
chance of being stored as fat rather than being  used by the body. 
Since amino acids are vital to the body's muscle, bone, hormones,
and enzymes, protein is not used as an energy source unless other
fuel sources are unavailable.  This would be the case in extreme
malnutrition or starvation.

The body's main fuel sources are carbohydrates and fats. 
Carbohydrates should constitute 50-60% of the total daily calories
consumed.  Carbohydrates may be divided into two groups - simple
and complex.  Simple carbohydrates have no nutritive value, they
are just empty calories.   Foods such as cookies, cake, candy,pie
and sugar-sweetened beverages are simple carbohydrates.  Such foods
should be limited in their consumption to no more than 10% of the
total daily carbohydrate intake.  Complex carbohydrates are found
in foods such as whole grain breads and cereals, potatoes, pasta,
rice, fruits and vegetables, nuts, and dried beans and peas 
Complex carbohydrates provide both bulk and fiber along with
vitamins and minerals.  The majority of your carbohydrate intake
should come from this group.  Carbohydrates are easily digested and
stored in the liver and muscles as glycogen - a ready form of fuel
energy.

Fats are the other primary source of fuel used by the body.  In
fact, fats are the most efficiently stored fuel.  Some stored fuel
is necessary, but the average American consumes 40-50% of this
total daily calories in the form of fat!  In reality, we should
strive to trim our fat intake down to 30% or below.  Examples of
some high fat foods are cooking oils, salad dressings, butter and
margarine, mayonnaise, peanut butter and lard.  Fats are broken
down into their components of fatty acids and glycerol which are
absorbed into the small intestine.  In the small intestine, the
fatty acids and glycerol are converted into triglycerides (three
fatty acids and a molecule of glycerol). Triglycerides become the
storage form of fats.  Fatty acids in combination with other
molecules form compounds which are essential for proper functioning
of the body.  More on fats and their role in energy production will
be discussed in the next section.

OTHER NUTRIENTS

In addition to the 3 basic nutrients, we need water, vitamins, and
minerals in our diet.  Water makes of 40-60% of our total body
wight and constitutes 65-75% of the weight of muscle and less and
28% of the weight of fat.  The average sedentary person requires
about 2.5 liters of water per day.  This water is supplied from 3
sources:  1) from liquids, 2) in foods, and 3) from metabolism -
the conversion of fuels into energy.  Without water, death will
occur within days because water serves as the body's transport and
reactive medium.  Some of the functions of body water are to supply
oxygen and food to the tissues and organs, remove waste products,
lubricate the joints, and help regulate temperature.

Vitamins are organic in nature and are needed in small amounts by
the body to perform specific functions.  If a vitamin deficiency
occurs, cells in the body will become unable to perform some
regular function, and symptoms will develop which are
characteristic of that particular deficiency.  Eating a well-
balanced diet will usually provide all the required vitamins. 
Remember, vitamins are not fuels; they are not substitutes for
proteins, carbohydrates, or fats.

Minerals are metallic elements that are essential to the body and
help to regulate many of its vital functions.  Again, following a
well-balanced diet will provide adequate amounts of minerals to the
body.

ENERGETICS

Consuming food is vital to us because our bodies need fuel to
function.  Metabolism refers to all of the energy and materials
transformations that occur in a cell.  Through a very intricate
cycle, the fuels and nutrients consumed combine with oxygen in the
cells to produce energy.  Each individual's energy needs will vary
due to numerous factors, including:

     +  Size -- heavier people need more food than lighter ones.

     +  Temperature -- people who live in cooler climates require
        more food than those in warmer areas because the body uses
        more energy to stay warm.

     +  Growth -- children, especially adolescents, need more food
        than adults to develop the muscles and tissues that       
        increase as they grow.

     +  Pregnancy -- pregnant women need more food for their  
        developing child.

     +  Activity -- people who are active use more energy than  
        sedentary people.

Energy is measures in CALORIES.  A calorie (actually, a
kilocalorie) is the amount of energy needed to raise the
temperature of one liter of water one degree Celsius.  The calorie
is the standard measure of the energy contained in foods and of the
energy intake and output of the body.

The body needs a specific amount of energy to sustain life.  This
is termed the basal metabolic rate (BMR), which is the rate at
which the body uses calories while in a fasted, rested state.  The
BMR for the average person is approximately one calorie per
kilogram of body weight per hour.  The BMR is regulated primarily
by the thyroid gland and tends to be stable and quite predictable.

To determine the total daily energy requirements, the number of
calories needed for physical activity and for digesting food must
be added to the BMR.  When we consume more calories than we use, a
positive energy balance exists and we tend to gain weight. 
Conversely, if we burn more calories than we consume, a negative
energy balance is created, and the body burns stored energy which
produces a weight loss.

Unfortunately, as we grow older, the BMR decreases and unless we
reduce the total number os daily calories consumed, a gradual
weight gain will become apparent through the years.

Specific energy values are associated with the 3 basic nutrients in
our diet -- protein, carbohydrates, and fat.  Protein gives off 4
Calories of energy per gram, carbohydrate yields 4 Calories per
gram, and fat which provides 9 Calories per gram.  Our body has
learned the efficiency of storing that nutrient which provides the
most energy per mass unit; therefore, fat has evolved as the
nutrient of choice for storage.  In addition, again for the sake of
efficiency, excess protein and carbohydrates can be converted to
and stored as fat.  So, there is more to developing a sound diet
than just counting calories.  We need to look at the composition of
the foods we eat.

A LOOK BEHIND THE CALORIE SCENE

Calories are important in a diet plan, but just as important should
be the proportion of the calories which are consumed from each of
the 3 nutrient groups -- protein, carbohydrates, and fats.  To
determine what percentage of a particular food is protein,
carbohydrates, or fat, you must know: 1) the total number of
calories contained in the food, 2) the number of grams of the
nutrient in the item, and 3) the specific energy value of each of
the 3 nutrients (as discussed in the above section).  As an
example, the composition of a broiled hamburger will be examined
below.

     Broiled Hamburger (one 3" patty)

          CONTENTS                      ENERGY VALUES
     Given Calories: 245            Protein       - 4 Calories/gram 
     Protein:         21g           Carbohydrates - 4 Calories/gram
     Carbohydrates:    0g           Fat           - 9 Calories/gram
     Fat:             17g

To determine Calories per gram:

     Protein:         21g x 4 Calories/g =  84 Calories
     Carbohydrates:    0g x 4 Calories/g =   0 Calories
     Fat:             17g x 9 Calories/g = 153 Calories
     Totals                              = 237 Calories
     (NOTE:  If you'll notice, the given calories sometimes do not 
      match the calories calculated.  Manufacturer's data on      
      nutrient content vary so use the Calories you calculate)

To calculate the percentages of each nutrient:

     Protein: 84 Calories/237 Calories = 35%

     Carbohydrates:  0/237 Calories    =  0%

     Fat:  153 Calories/237 Calories   = 65%
     Totals:                           = 100%

As indicated by this example, the food contains 65% fat.
  
By examining food labels and purchasing a calorie book which
contains a broad spectrum of foods (or obtaining appropriate
software to crunch the data for you), you will be able to more
closely monitor the foods you eat.  However, you do not need to be
a slave to a calculator or computer.  After 4 weeks of reading
labels, determining calories, and calculating percentages, you'll
find that your ability to approximate calories and percentages will
help decide which foods are the most nutritious.

WEIGHT REDUCTION

A combination of diet and exercise is recommended for weight
control for a majority of asymptomatic individuals.  But, why
exercise when you can maintain an ideal weight by remaining totally
inactive?  The answer is simple.  Besides the obvious benefits
derived from an exercise program (improved cardiovascular
endurance, strength, improved muscle tone, enhanced self image,
etc.), exercise in conjunction with a diet is a much easier regimen
to maintain than diet or exercise alone.  Also, by including
exercise as part of your weight control program, you can actually
consume more nutritious calories per day.

Contrary to what most people believe, aerobic exercise of moderate
duration, intensity, and frequency, will not cause an increase in
appetite.  In fact, studies have shown that exercise may even
suppress the appetite!

As a final note, dieting can cause a loss of lean body mass (muscle
tissue).  An exercise program will counteract this effect because
exercise promotes building, or stabilizing, of lean body mass. 
Since fat is what we should be striving to lose, just remember,
that an exercise program can do both for you -- promote loss of fat
and retention of lean body mass.

SUMMARY

As you can see, there is more to maintaining your ideal weight than
simply counting calories or crash dieting.  Some final tips which
may make the establishment of good nutritional habits easier are:
1) learn to BALANCE your meals.  If you eat foods which are
overabundant in one nutrient, usually it will be fat <as fat is
real popular with the taste buds>, make a conscious effort to
reduce sources of that nutrient so that your total intake is
balanced; 2) Allow for a VARIETY in your meals.  Selecting foods
from the Basic 4 Food Groups is the best way to assure a well-
balanced diet; and 3) practice MODERATION each time you sit down to
eat.  Cut down the portion size of your meals and try to place less
emphasis on some not-so-healthy foods, especially caffeine and
alcohol (alcohol provides 7 calories/g and contributes no nutritive
value to the body).  The information provided in this section is
meant to help you become more familiar with nutrition and the ways
in which sensible and careful eating habits can enhance your
lifestyle.  The information provided is, by no means, a blanket
diet plan for everyone.  An individualized program requires a more
in-depth analysis of lifestyle habits.  Good nutrition is
important.  It is something that WE CAN CONTROL in our lives, and
in return, we will be rewarded with more efficient bodies and
increased energy to perform our daily tasks.


NOTE: Additional reading about fat can be found in LIBrary 10, Nutrition,
FAT.TXT.  Also, there are several software programs available to help
track the foods use consume.  

Allan G. Stevens 76702,562