A
Calorie is a Calorie… Or
is it?
Edward
H. Nessel, R.Ph, M.S., MPH, PharmD.
It
may be that most Americans are obsessed with being thin, but if you
look around you’ll see that most are overweight. In fact, at least
one-third of the adult American population is approaching obesity
(depending upon height, at least 20 to 30 pounds overweight), and
nearly one-half are considered overweight. This is more than a 10%
increase from the 1980’s, and the number continues to climb.
We also know that several potentially catastrophic diseases can
arise from being overweight. For example, coronary heart disease (CHD)
and diabetes are now both definitely linked to an expanded
waistline. We also know that those wanting to partake in athletics
will definitely be at a disadvantage carting around more
non-muscular body weight than they should.
So how do we reduce our nation’s fat and your waistline?
Consistently inserting moderate to vigorous exercise in the
daily/weekly schedule is a proven way to fight the bulge. But if you
don’t follow a low-fat diet, in conjunction with your regular
exercise program, you may be waging a losing "battle of the
bulge."
There has arisen of late a major dietary controversy over what type
of foods (or which type of diet) actually causes the most harm in
regards to increasing body fat. Atkin’s Diet followers believe
that it is mainly carbohydrates (simple and/or complex) that produce
the unwanted fat, while consuming fatty dishes and protein at will
is the way to body leanness. There have been weight-loss situations
on the Atkin’s Diet; enough so as to make many stop and consider
is this a possible avenue to permanent weight loss. They should also
ask the big question: is this the safest way to a permanent ideal
body weight?
To lose weight, the obvious should be clear: take in less calories
than you burn up with activity; or to put it in a more logical way:
burn up more calories than you take in throughout the day, the week,
the year. By this I mean consistency. Going on a diet should not be
the goal of the weight-loss seeker; entering into a life-style
change in eating describes what should be the intended objective.
Many health professionals say you have to go on a low-calorie diet
to lose weight; true but too simplistic. They say "A
calorie…is a calorie…is a calorie" and "All excess
calories will be stored as fat." Be cautious of these warnings.
They are only half-truths, and are not the main issue when dealing
with weight control. You do not eat calories, per say; you eat
carbohydrates, fat, and protein. And each of these food groups are
utilized and stored differently by the body.
What is a Calorie?
A kilocalorie (Kcal…1000 calories) or what we conveniently refer
to as a calorie, is a measure of heat energy. Scientifically, it
represents the amount of heat needed to raise the temperature of one
kilogram of water (slightly more than a quart) by one degree
Celsius. For example, a can of chicken noodle soup with 90 calories
per serving has the chemical energy in one serving to raise the
temperature of 90 quarts of water by one degree Celsius, or 1 quart
of water 90 degrees. But if the can of soup is actually chemical
energy that produces heat, what happens when you eat it?
Where Does It All Go?
The protein in the soup (coming mostly from the chicken), which
equals four calories per gram, is broken down and then reassembled
to replace protein in your body lost by routine cell turnover,
especially in the muscles. Some of the protein is also used to make
enzymes and other key chemicals needed to make your metabolism work
Suppose you add up all the protein in your daily diet, and it comes
to more than your body needs. What happens then? The calorie
counters say it is all turned into fat. But this would call for some
monumental biochemical processes to occur, and the scientific
literature does not support this type of metabolism. What happens is
that the excess protein is oxidized, which means it is burned off
and converted to compounds that are eliminated from the body
(assuming the kidneys are up to the task).
What happens to the fat in your soup, and from the other foods you
eat? Some replaces lost tissues such as cell membranes and certain
cells in your nervous system. The rest is first utilized as energy
for body function and movement. But since fat is the highest food
energy source (providing nine calories per gram), it is quite easily
stored as such by the body for later use. Nature has always provided
this biochemical energy pathway. The trouble with all this is that
the body’s ability to store fat is seemingly limitless. People who
consistently eat more fat than they can burn up keep storing it day
after day…getting fatter and fatter.
The fate of the carbohydrate in the chicken soup (coming from
vegetables and pasta), and from the rest of the daily food intake is
more interesting. A little carbohydrate (CHO) is utilized in cell
turnover, but the majority is consumed for muscular energy. Although
it only produces four calories per gram, carbohydrates provide the
"high-octane" readily-usable fuel the body needs to move
though all the demands we choose to put it through. Thus, a diet
consisting predominately of carbohydrates will provide plenty of
energy upon demand.
What if you eat too much carbohydrate? The calorie counters say it
is simply turned into fat. However, the scientific literature tells
a different story. Some extra carbohydrate can be stored as
glycogen, which is the breakdown product of carbohydrates and
the storage component of glucose; glucose is the prime energy source
the body seeks to move muscle and everything else attached to same.
This glycogen is stored somewhat in the muscles proper for an
increased ready supply of energy and stored to a greater extent in
the liver, which is the second line of defense against energy drain.
If one eats more carbohydrates than the body can store, the rate of
oxidation increases. The body "turns up the heat" and the
basic metabolic rate (BMR) is raised burning carbohydrate faster.
Only when the body has filled all possible stores and turned up the
burners full blast can it begin converting some of the extra
carbohydrates into fat. And by this time, very large amounts of food
would have had to be consumed.
Results from clinical nutrition studies show that the conversion of
carbohydrate to fat in healthy physically active people is minor,
compared to storage of dietary fat. The body only readily
converts carbohydrate to fat if the body is deprived of fat, or it
needs more fat as in the third trimester of pregnancy, or it has
MUCH more caloric intake than it needs on a daily basis.
What has come to be of tremendous benefit to those who train
intensely on a regular schedule is the scientific discovery that a
certain proportion (4:1) of carbohydrate to muscle-friendly protein
(whey) can have a synergistic effect in powering the muscles and
allow them to recover faster and more completely than they would
otherwise be able with carbohydrates alone.
What Should You do?
The evidence that counting grams of fat is the key to weight control
is well documented. The mechanism for the process is logical and
true, and the scientific literature supports it. The evidence that
simply counting calories is the way to go is inconsistent, seldom
corrected for the known influence of fat, often flawed, and there is
no mechanism to explain how those excess calories contribute to
weight (except for those from fat), that is consistent with human
biochemistry.
It is very hard to overeat on pure carbohydrate foods because they
are bulky and often contain a lot of water. A good rule of thumb is
if you are in good health, have a normal metabolism, and exercise
regularly, consuming one gram of fat for each kilogram (2.2 lbs) of
body weight (or target body weight) will not add on the pounds
Americans seem to be so attached to.
It is never a pleasant situation to cut out your favorite foods to
lose weight; that is why so many diets fail. The best way to lose
weight and keep it off is to remove as much fat from the diet as
possible. Always select the low-fat alternatives; your taste buds
will become accustomed sooner than you think. Choose several
servings a day of fresh fruits, vegetables, breads and pastas (minus
the high-fat spreads or sauces) with a complimentary amount of
quality protein and as little fat as you can get away with. There
will always be too many opportunities to consume fats; work at
dodging them as you would anything that would jeopardize your
working out.
Ed Nessel is a pharmacist, biochemist and physiologist who coaches
age group and masters swimming at Rutgers University. He is the USMS
National Librarian and was selected the 1998 USMS Coach of the Year.
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