Weight
Loss Theories by
Maia Appleby
Why can some thin people eat whatever they
want without gaining weight, while many overweight people
remain heavy no matter what they do? Here are some thoughts:
The other day, I was visiting with two sisters
I know, discussing their eating patterns. Although
they’re about the same height and close in age,
Sue (who is a little chunky) was bemoaning the
fact that her “lucky” sister Kathy can “eat
whatever she wants and never gain a pound.”
In fact, they joked, Kathy was a much more voracious
eater than Sue had ever been; yet this difference
in their body shapes had always been the same.
Passing it off as conflicting metabolism patterns,
they learned to live with it (or, should I say,
Sue learned to live with it).
They’re correct in saying that it could result
from a basal metabolism difference. Kathy was
an active kid (although she isn’t today) and
appears more muscular than her sister. Sue was
always quieter and is still basically sedentary,
and she looks like she carries more body fat
than Kathy. This would lead us to assume that
due to her greater ratio of muscle to fat, Kathy
naturally burns more calories each day and therefore
can eat more. It makes sense, right?
Well, this is only part of it. The question is: what causes
their metabolism rates to be so entirely different?
Last year, Sue went on a diet. It wasn’t a very healthy
diet, though. She essentially restricted her caloric intake
to about 800 per day for a full month. She lost ten pounds
that month, a feat that she was very proud of, but soon,
she stopped losing weight. She had hit a plateau, and 800
calories per day had become what she needed to maintain
her current weight. She grumbled with discouragement when
the scale stopped showing a reduction, and she went off
the diet, feeling like a fat-fated failure. Again.
What do you think happened to Sue’s body then?
You guessed it – she gained the ten back, with
interest. She had been losing weight like crazy
all month long. Why would this happen?
The Setpoint Theory
One possibility lies in a weight control theory
called the Setpoint Theory. This was developed
when several researchers indicated that each
person’s body has an established weight (a “setpoint”)
that it strongly tries to maintain. According
to the theory, the body determines how much
fat it wants to hold, and as the caloric intake
climbs and falls, the body adjusts its basal
metabolic rate to maintain that fat-to-muscle
ratio.
This can work either way. At Rockefeller University
in New York, researchers monitored many Sues
and Kathies who had recently lost 10% of their
body weight. It was found that, as their bodies
worked to regain the weight, they began to burn
calories more slowly (15% fewer calories than
expected for their weight). When the Sues and
Kathies began the study by gaining 10% of their
body weight, they began burning 10 to 15% more
calories than what would be expected, indicating
that their bodies were attempting to lose the
extra pounds and get back to their pre-set weight.
At the risk of spoiling any mystical charm
implied here, the setpoint is probably just
a defense mechanism that we inherited from our
ancestors. Back in less luxurious generations,
people lived at the mercy of the weather and
the forces of nature. There were times when
food was plenty and there were times when they
might go for days between meals. Their bodies,
accustomed to this fluctuation, reacted to fasting
periods by holding onto as much body fat as
possible to prevent or postpone starvation.
Today, most of us don’t have to live with such
hardships, but our bodies are still programmed
for them, whether we like it or not.
The Fat Cell Theory
Another good candidate for explaining this is the Fat Cell
Theory, which has been tossed around for about thirty years
now. It attests that fat cells are usually formed either
in early childhood or at puberty. A child who consumes a
large number of calories from fat can actually grow new
fat cells (hyperplastic obesity), whereas an adult will
keep the same number of fat cells and they just expand (hypertrophic
obesity).
Having a larger number of fat cells make it
much more challenging to maintain a healthy
weight in later years. Lean eating and exercise
shrink these cells, but since there are so many,
it’s impossible to lose much of the excess body
fat. Extremely obese adults can have as many
as five times the number of fat cells that leaner
adults have, making exercise seem pointless
and ineffective.
Although hyperplastic obesity is thought to
be quite rare, it’s definitely something we
should know about, especially those of us who
are raising children. The hypertrophic type
is much more common. Most of us who have packed
on a few extra pounds here and there have simply
expanded our fat cells, and shrinking them takes
a little diligence and discipline.
HOW TO LOSE IT
At any rate, whatever we believe to be the cause
of weight gain, the solution is crystal clear.
A combination of aerobic exercise and a diet
high in complex carbohydrates is the best, longest-lasting
weight loss strategy there is.
THE CARB RUMOR
Complex carbohydrates, also known as polysaccharides, are
found mainly in plants. Corn, nuts, seeds, legumes and roots
are all sources of complex carbohydrates, but for nutritive
purposes, your best bet is in grains and other fiber-rich
food sources. Whole-grain cereals, breads, fruits and legumes
are wonderful choices with lots of nutritional virtues.
A healthy diet is comprised of more of these than anything
else.
Remember that one gram of carbohydrate has only four calories,
where a gram of fat has nine, so you can eat twice as much
of the former, causing that feeling of fullness to occur
after fewer calories are taken in.
When you hear someone say that bread makes
you fat, don’t believe it. This is only true
of certain groups of people – not the general
population, and this notion has had a weed-like
effect on health enthusiasts around the world.
Carbohydrates may cause weight gain in people
who are either already morbidly obese or extremely
sedentary. Very heavy people have a hard time
using insulin efficiently, and carbohydrates
tend to release increasing amounts of it. Since
insulin is needed for the body to convert glucose
to energy, if this function is impaired due
to obesity, Diabetes or whatever else, the glucose
is simply converted to fat, resulting in weight
gain.
Most bodies immediately convert carbohydrates to energy,
however. If this energy is used on physical activity, the
body burns fat in the process. If energy is taken in, but
the body doesn’t move (for example, if someone sits on the
couch, watching TV, eating cereal and fruit and all that
good stuff), the energy has nowhere to go, so the body converts
it to fat.
Carbohydrates don’t make this person fat – it’s just that
inactive people don’t use carbohydrates as energy nearly
as efficiently as active people do.
People who exercise need lots and lots of
carbohydrates for energy. You cannot, in any
healthy manner, improve your ability to burn
fat without exercising, so ignore all the hype
about carbs being fattening. Hopefully, that
whole craze will be over in a few years, once
it finally becomes officially established that
it’s unhealthy.
When you begin increasing your aerobic activity and fiber
intake, it’s vital that you also drink
plenty of water (at least two liters per day). Your
body will need it, and it will help you burn fat much more
quickly by keeping your liver and kidneys in check. Your
liver can’t metabolize fat very efficiently at all without
sufficient water.
AEROBIC EXERCISE
Aerobic activities include walking, jogging,
bicycling, dancing and swimming. Anything that
you do that involves the large muscle groups,
which you can sustain for thirty minutes or
longer, is considered aerobic. It should be
done a minimum of five days a week for at least
thirty minutes each session.
It should be intense enough to get your heart
rate up, but not so intense that you become short of
breath. In other words, you should be able to have a reasonable
conversation during the activity, but you shouldn’t be able
to recite the Gettysburg Address without becoming winded.
Above all, it should be an activity you enjoy.
If you hate the treadmill, don’t chain yourself
to it. Find something that you love and make
it a can’t-miss part of your daily routine.
Alas, some of us have to work harder than
others to maintain slenderness. Consider it
a character-builder. Remember, also, that by
the discipline and sweat required to lower your
setpoint, you are also strengthening your heart,
lowering your blood pressure and LDL cholesterol
level and probably prolonging your life.
Kathy might stay thinner than Sue with no
effort whatsoever, but who knows how healthy
she really is? Sue might actually be the lucky
one, if you think about it. She has a good,
strong driving force to do good things for her
body, and that will surely pay off in the years
to come.
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