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Losing a Few Pounds May Help the Obese
For the obese, a small loss may
be a big victory. Evidence is building that really heavy people
may be able to greatly improve their odds of dodging weight-related
illnesses while remaining very heavy.
The secret: Lose just a few pounds.
Weight reduction, it appears, is powerful medicine for the large,
no matter how seemingly insignificant the dose.
Many obesity experts agree that
getting down to a normal size may not be necessary to avoid much
of the bad effects of being big. Dropping just 10 or 15 pounds
too little to even miss on many people can have
a surprising and substantial effect on the body processes that
obesity disrupts.
If true and the idea still
has some skeptics this means that at least a partial antidote
to the apocalyptic predictions about the obesity epidemic may
be within reach, even if people remain vastly overweight by every
measure.
"The bad news is people are getting
more and more obese," says Dr. Christie Ballantyne, a cardiologist
at Methodist Hospital in Houston. "The good news is losing a modest
amount of weight can have really profound health benefits."
Of course, many big people want
to slim down so they will look better. But doctors say the best
reason for getting control of weight is to be healthier.
"That is one of the most important
public health messages to get out to people," says Dr. Judith
Fradkin, diabetes endocrinology head at the National Institute
of Diabetes and Digestive and Kidney Diseases. "The goal should
be to become healthy, not become a fashion model. If you move
in the right direction even a little bit, that can make a big
difference in health."
That's good news for people who
throw up their hands in defeat because they cannot get down to
their ideal weight. Just a loss of 15 pounds for someone 90 pounds
too heavy can make a big difference, Fradkin says.
There is little doubt among mainstream
experts that obesity is a potentially deadly condition, blamed
for about 300,000 deaths annually in the United States alone.
For a middle-aged person, it is considered to be about as bad
for health as smoking is.
Many experts believe that the real
hazard of being overweight is the torrent of hormones and other
chemicals pumped out by fat storage cells, which become hyperactive
when filled to capacity with fat.
The damaging effects of obesity
are obvious on a physical exam. Not every nondiabetic, overweight
person has all these abnormalities which can raise the
risk of heart attacks, diabetes and strokes but many do.
The most common:
_HDL cholesterol, the good variety,
is unusually low below 40 in men and 50 in women
even though the bad LDL is normal.
_Blood pressure is 130 over 85
or greater.
_Fasting blood sugar is between
110 and 126.
_Free-floating fats called triglycerides
are over 150.
_C-reactive protein, a sign of
bloodstream inflammation, is high, often over 3.
Experts believe that overactive
fat can do all of this, at least in part by making the body less
receptive to signals from insulin that tell it to store up energy.
As a result, the liver has to produce more insulin, which can
be harmful itself at high levels and raises the risk of diabetes.
The benefits of losing just a bit
of weight are often apparent in people with a body-mass index
well into the obese range 35 and beyond. Typically, these
people are at least 50 pounds overweight and often much more.
In his weight clinic, Ballantyne
watched patients whose BMI's averaged 41. After losing about 7
percent of their weight in a month, most of these ominous signs
got substantially better, even though their BMI's still averaged
38.
Their blood pressure fell to normal.
Triglycerides dropped 40 percent back into the healthy range.
Inflammation dropped between a quarter and a third. HDL budged
upward slightly.
In many cases, the benefits are
as big as typically seen with a fistful of pills, says Ballantyne.
"You are altering the metabolic functions more profoundly than
the weight, which is great news."
Doctors say people whose weight
continues to fall do best, and those who put some of it back on
lose part these improvements. Still, they seem much better off
having lost and partially regained than never having lost at all.
The biggest questions, though,
are how long these improvements last and whether they translate
into better survival, as doctors expect they should.
"I think it would probably help
them," says Dr. Xavier Pi-Sunyer, head of obesity research at
St. Luke's Roosevelt Hospital Center in New York City. "But is
there good evidence this is so? We don't have it."
In fact, there is little firm evidence
that losing weight, either big amounts or small, translates into
longer life. Some of the best data comes from two large studies
published in recent years on overweight people who are at high
risk of diabetes.
Both show that a little weight
loss and exercise reduces the risk of this disease and presumably
its complications, including heart attacks, kidney failure, blindness
and early death. In the larger of the two, people who shed an
average of 12 pounds and walked 20 minutes a day over three years
cut their diabetes risk in half.
But why? Exercise almost certainly
helps, many say, but the critical importance of a small weight
loss also makes biological sense.
Very overweight people have more
fat cells than normal-size folks, and their fat cells are also
more biologically active. When people lose weight, these fat cells
shrink.
"When you go from a BMI of 39 to
36, you still have got a lot of fat cells," says Dr. Michael Jensen,
an endocrinologist at the Mayo Clinic. "But instead of a lot of
big fat ones, you have a lot of small ones. They do a better job
of regulating hormones and fuel release than do big fat cells.
That's why you get a big improvement in health when you still
have excess body fat."
Dr. Ken Fujioka, a nutrition expert
at the Scripps Clinic in San Diego, says if someone loses 5 or
10 percent of their weight, their body does not want to lose any
more, so it slows its metabolism. While that makes further weight
loss more difficult, it still seems to be beneficial.
"It keeps the blood sugar and cholesterol
in much better control," he says. "If your body learns to live
off less calories, and it can, it seems to be a good thing."
On
the Net:
Diabetes study: http://content.nejm.org/cgi/content/abstract/346/6/393
Reference
Source 102
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