Chapter 01 – Physiology

Chapter 1 – Basic Physiology

Being Over-Fat

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Did you know that excess body-fat can lead to a multitude of health problems?  For one thing, excess body-fat can precipitate hypertension thus increasing the risk of stroke.  Fat gain can also increase the likelihood of diabetes in genetically susceptible people and, thus, bring on its associated ills.

Excess body-fat (especially in the central abdominal area of the body) also increases the risk of heart disease by worsening atherosclerosis.  Other physical conditions associated with over-fatness include abdominal hernias, some cancers, varicose veins, gout, gallbladder disease, arthritis, respiratory problems, liver malfunction, complications in pregnancy and surgery, flat feet and even a high accident rate.

Social, Economic & Psychological Effects

Here’s something else to consider.  No one who is fat in America escapes the social and economic handicaps.  Research has shown that to this day, over-fat people are discriminated against.

Goal Setting and Keeping Score

That’s the bad news.  The good news is most people are NOT obese. Nonetheless, most people desire to lose some degree of body-fat.  Therefore, the extent of our over-fatness — and the amount we wish to lose must be determined.  This way goals can be set and progress monitored.  Once your goals are established, you should record your progress in a daily tracking journal or diary.

Throw Away Your Scale

Here’s the best advice you’ll ever hear in regard to weight-management — “THROW AWAY YOUR SCALE.”  The focus (obsession) on weight is the very reason why most people fail.  It’s mis-guided and dangerous.

The focus on weight began back in the 1950’s when the definition of appropriate weight was simple.  Your weight was compared against the “ideal weight” tables developed by the Metropolitan Life Insurance Company.  If your actual weight was twenty percent (20%) or more above the table weight, then, you were considered obese.  If it was ten percent (10 %) under, you were underweight.  Today, however, the term ideal weight is irrelevant.

Beware:  Some medical doctors still use the Metropolitan Life Tables.

The original weight-table standards were designed for insurance purposes — not as guides for nutrition and fitness.

These tables never considered body-composition.  Most world-class body-builders (usually less than 8% body-fat) and other athletes would be categorized “obese” by the original weight-tables.

The way to measure and determine one’s fat to lean muscle proportion is to determine body-fat percentage.

The body-fat percentage is the percentage of an individual’s weight that is fat.

Body-Fat Vs. Lean Mass

It is lean mass that plays the key role in any type of weight-management program.  Whether you’re interested in fat-loss or muscle gain, lean mass requires certain conditions in order to make a change in body-composition.  It’s imperative to understand that the lean mass of an individual is directly related to metabolism.  More about this later.

Can I Touch a Calorie?

Here’s another confusing issue.  Calories.  Some think calories are something you add or remove to the diet.  It’s as if a calorie is an entity in and of itself.

This is false.

A calorie is a unit of measure.  It’s used to designate the body’s energy requirements.  The word calorie relates to “combustion” or, to produce energy.

By definition, a calorie is:  The amount of heat required to raise the temperature of 1 gram of water 1 degree Celsius.

Combustion of Proteins, Fats and Carbs

Generally speaking, proteins, fats and carbohydrates provide different rates of combustion.

Fat is one of the most efficient, compact sources of energy in all the foods you eat.  One gram of fat when burned in the body will yield 9 calories.

Proteins and carbohydrates are not as efficient.  The rate of combustion for both of these fuel sources is 4 calories per gram.  Thus we have a 9-4-4 ratio of values applied to the main elements of a menu.

Conversion Rates

The conversion numbers 9-4-4 are used to convert a given amount of food (1 gram) into calories.  Thus 100 grams of protein (x 4) is worth 400 calories.  10 grams of fat (x 9) is worth 90 calories, and 200 grams of carbohydrates (x 4) is equal to 800 calories.

A Brief Overview of Metabolism

Your metabolism is the total amount of energy required by all your bodily functions for one day.  It’s imperative to understand that in order to make a positive change (whether fat-loss or a muscle-gain), your body requires a certain metabolic (expenditure) and caloric (consumption) combination in order for that change to occur.

Energy Out

Two activities occur in the human body that contribute to energy expenditure.  One activity is the fueling of the basal metabolism.  The second is the fueling of its voluntary activities.

Basal Metabolism

The basal metabolism supports your bodily functions that occur without conscious awareness.  This includes the heartbeat, breathing, maintenance of body temperature and the sending of nerve and hormonal messages to direct these activities.  They are the basal processes that maintain life.

The amount of energy required to maintain the these functions is called the basal metabolic rate (BMR).  The basal metabolic rate is the minimum amount of calories needed to sustain the vital functions of the body during a relaxed, reclined and waking state.  BMR is proportional to the body size, lean mass and surface area of an individual.

The BMR is surprisingly fast.  A person whose total energy needs are 2,000 calories a day, spends as many as 1,200 to 1,400 of them to support basal metabolism.

You cannot directly change your BMR, today.  You can, however, change the second component – voluntary activities – and spend more calories today.  By increasing your daily voluntary activities day after day, it will ultimately change your BMR.

Voluntary Activities

In order to make favorable changes in your body, one of your primary goals is to increase your Basal Metabolic Rate.  You can increase your BMR by making exercise a daily habit.  This will increase your body-composition toward lean.  Lean tissue is more metabolically active than fat, so, your basal energy output also will increase.

The amount of energy you spend in exercise depends on your personal lifestyle and exercise preferences.  For example, the larger the muscle groups you use in your activity, and the more time you consistently invest, the more calories you spend.

Voluntary activity of exercise is the most immediate change you can make to help increase daily caloric expenditure.  Whether you are interested in fat-loss or muscle gain, increasing energy expenditure through consistent daily aerobic exercise will ensure that weight-loss is due to fat-loss rather than muscle tissue.

Now that you understand the two basic expenditures of metabolism; basal metabolic rate and voluntary exercise expenditure; let’s explore the necessary conditions for change to occur.

Energy Balance

Regardless of popular theories behind behavior and metabolism, people in the real world gain and lose body-fat.  How does this happen?  It occurs due to an unbalanced energy budget.  That is, by eating (consuming) either more or less food energy than they spend.  There is an energy balance when the caloric intake equals the caloric expenditure.

Positive Energy Balance

The primary cause of excessive body-fat and obesity is an energy imbalance in the body.  Let’s examine a positive energy balance.  A positive energy balance occurs when the intake of calories (food) exceeds the expenditure, (you eat more than you spend).  For every 3,500 calories of excess food consumed — that the body does not burn for energy — one pound of fat is stored in the body.

Improper diet, overeating, hormone disturbances, physical inactivity and even extensive dieting may create a positive energy balance which leads to weight gain.

Positive Energy Balance Can Be Good

A positive energy balance is not always bad.  In fact, for those interested in increasing their weight/lean muscle mass, a positive energy balance is essential.  Athletes and body-builders typically must consume more calories than the basal metabolism requires.  This positive energy balance, coupled with correct exercise, will stimulate and accommodate new tissue growth.

An increase in lean mass will occur as long as there is enough weight training to substantiate the growth of lean muscle tissue during a positive energy balance.

Negative Energy Balance

Here’s how you’ll lose body-fat through a negative energy balance.  When the caloric expenditure exceeds the caloric intake, a negative energy balance occurs.  You burn more calories than you consume.  The most effective way of producing this deficit is through proper nutrition and productive exercise.  More specifically, a personalized nutrition plan to meet your body’s needs and an effective exercise plan designed to achieve your goals.  Correctly setting up these two variables can ensure that metabolism will be enhanced and any weight-loss is due to fat-loss — not the loss of lean muscle.

It All Starts With Food

Nutrition is essential to metabolism.  Every individual requires a specific amount of food to meet their metabolic needs.  The amount of calories is dependent upon the change of body-composition you desire.

To achieve fat-loss, a slight negative energy balance must be present for it to occur.  However, the negative energy balance must not fall below the requirements of the basal metabolic rate.  When the basal metabolism receives all of the necessary fuel requirements, it can function efficiently enough to burn the unneeded fat stores.

When calories are eliminated or reduced to a level below what is required by the basal metabolic rate (BMR), the diet will have an adverse effect on the individual’s body-composition and health.

Don’t Burn Lean Muscle Tissue

The body’s first choice for fuel is stored glycogen (blood sugar).  After the glycogen has been depleted, the body must obtain more glucose to keep its nervous system operating.  At this point, an inactive, underfed body will turn to protein, its own lean muscle mass, to feed its basal metabolic rate.

Many dieters believe the body will burn fat as its alternative source of energy.  This is wrong.  At this stage, fat stores are of no use to the nervous system.  Here’s why.

The nervous system and brain are the central controllers in the body. They can only use glucose (blood sugar) as fuel, and it is imperative that they find fuel.  The muscles and organs may use fat as fuel, but the nervous system cannot.  Also, the body possesses no enzymes that can convert fat to glucose.  The body does, however, have enzymes that convert protein to glucose.

So, if fuel is not available, the body converts its own lean tissue and muscle mass into glucose to feed its nervous system and metabolism.  In fact, if the body were to continue to consume its lean tissue unchecked, with no other fuel sources, death would ensue within a few weeks.  After all, not only skeletal muscle, but also the liver, heart muscle, lung tissue, blood cells — all vital tissues – are being burned as fuel.

The Wrong Way

Herein lies the problem with most conventional weight-loss programs.  They are faulty in design for the very reasons just explained.  Conventional diets lower the caloric intake below the basal metabolic rate to create an EXTREME negative energy balance.  This method will incur weight-loss, but it will be a result of muscle or lean mass loss (protein).

It’s important to realize that when the calories drop below the minimal amount of energy required (BMR) to feed the nervous system, the body perceives starvation.  When this occurs, not only does the body burn muscle to fuel its energy requirements, but while doing so, it is actually slowing down its metabolism.  By ridding itself of muscle, the body is essentially ridding itself of metabolism.

This is where the fat storage occurs during dieting.  While shedding muscle under this perceived state of starvation, the body will store whatever it can as body-fat to protect itself.  It also will respond to the threat of starvation by increasing the fat-depositing enzymes which will in turn store more fat!

The long term effects of dieting (especially without physical activity) will produce a negative effect on body-composition.  A person who lowers calories below his or her BMR and loses muscle mass through dieting, will lower his or her metabolism.  (Remember metabolism is directly proportional to the amount of lean muscle mass).

Lowered Metabolism

By lowering the metabolism, the body now requires fewer calories.  If the calorie consumption increases, the individual will gain back more fat than lean muscle mass (especially without physical activity).  Each time a person loses weight and regains it while remaining inactive, the metabolism will require fewer calories.  If a person eats the same amount as they did before the last diet, he or she will not maintain (because they lost the lean muscle mass) but will, instead, gain weight!

This explains the yo-yo dieting effect.  Each round of dieting, without physical activity, is followed by a rebound of weight to a higher level than before.  The body-fat content increases and caloric needs fall after each round, making the next round of weight-loss more difficult.

There’s Only One Way

Remember, metabolism will define what our bodies will be — or become.  The basal metabolic rate is the minimum amount of energy required to fuel our basic physiological functions.  Any decrease in calories below this BMR will result in a decrease in lean muscle tissue.  A decrease in muscle tissue slows metabolic expenditure, which leads to an eventual increase in body-fat to protect the body from perceived starvation.

In order to make a favorable change in your current body-composition, the appropriate conditions must be consistently maintained for the desired change to occur.  For weight/muscle gain, the body must experience a positive energy balance.  By consuming more calories than the current BMR requires, an effective weight/strength training program will stimulate the desired growth.

For weight/fat-loss to occur, an individual must consume enough calories to maintain and support their BMR and create a slight negative energy balance by increasing voluntary physical activity.  It’s that simple.  Remember, all desired changes in body composition rely upon the metabolism to build muscle or burn fat.