It's part of the American persona to be big, larger than life -- robust in that Paul Bunyan, Davy Crockett, John Henry sort of way. Heroic dimensions fit a heroic country.
But over the past few decades, Americans have been living ever
larger in ways that may not be so good for us. Measured by the scale
of body-mass index, the weight-to-height ratio that's the foundation
of most obesity studies, 65 percent of Americans are considered
overweight or obese.
Estimates of how significant those extra pounds are to health vary,
however. A 2004 study by the federal Centers for Disease Control and
Prevention calculated that obesity contributes to as many as 400,000
premature deaths each year in the United States. A statistical
re-check of that study a year later rolled that toll all the way down
to 26,000 a year.
The updated study confirmed the long-held view among obesity
experts that being at least 50 pounds overweight is hazardous, but
also found that being as much as 40 pounds overweight actually seems
to protect people from early death.
Many experts say ranking high on the BMI scale may not reflect how
"fat'' someone really is or to what extent his or her weight
represents an increased risk for various medical problems or premature
death today or years later.
"No one has ever suggested that BMI is the only criterion to use,
because it clearly is not,'' said Dr. George Bray of the Pennington
Biomedical Research Center in Baton Rouge, La.
Factors like a person's age, level of physical activity, rate of
weight gain, blood pressure and cholesterol levels also have to be
taken into account in measuring an individual's health, he added.
Some researchers prefer to consider how much fat is under the skin
in select spots; other recent studies suggest that waist size is the
telltale statistic. By that standard, people should watch out if it's
greater than 40 inches for men or 35 inches for women, studies show.
The different standards bring mixed results, particularly when
athletes are measured. For instance, one 2003 study involving 53
players on the Indianapolis Colts found that while the BMI showed many
of the players to be overweight, their percentage of body fat was well
below the 25 percent range that marks obesity. But another study, done
with Division I college football players the same year, found that
offensive and defensive linemen were, on average, carrying greater
than 25 percent body fat.
Still another 2003 study found increasing rates of sleep apnea and
high blood pressure among pro-football players and especially among
the biggest linemen.
There's lots of evidence that being fit can trump bulk when the
relative risk of developing diseases ranging from heart disease to
cancer is analyzed.
"We've studied this from many perspectives in women and in men,
and we get the same answer: It's not the obesity, it's the fitness,''
said Steven Blair, president and chief executive of the Cooper
Institute for Aerobic Fitness in Dallas.
At the same time, being big may take a toll on systems from bones
and joints to the liver and hormonal system that regulates glucose
levels in the bloodstream, which influences not only the heart and
blood vessels, but also body systems that regulate cell division and
increase the odds for cancer.
Obesity produces hormonal and metabolic changes that make it easier
for cancer to gain a foothold. "Overweight and obesity has a very
broad impact on cancer across most cancer sites,'' said Eugenia Calle,
a researcher with the American Cancer Society.
And to the extent that many athletes use anabolic steroids to bulk
up, they also increase their risk for a variety of health problems,
ranging from blood clots and muscle injuries to premature heart
attacks and strokes.
Ruth Wood, a professor of neurobiology at the University of
Southern California, has found increasing evidence in animal studies
that steroids may be physically as well as psychologically addictive
for athletes. But she also noted that her research and that of several
other scientists confirms that taking large amounts of steroids can
produce more aggressive behavior.
While there have been many individual reports of steroid abusers
having episodes of "'roid rage'' in recent years, Wood said the fact
that athletes "feel better when they're taking them than when they're
not'' suggests that people taking the drugs may feel invulnerable and
thus more prone to take risks in general.
And studies with hamsters by Richard Melloni, a behavioral
neuroscientist at Northeastern University in Boston, have found that
steroid use may influence players long after they stop taking the
drugs: "What we know at this point is that aggressiveness doesn't
simply cease after the ingestion of steroids does.''
Just old-fashioned physical training causes endurance athletes'
hearts to actually enlarge to handle the added aerobic burden they put
on their circulatory systems. But those thicker heart muscles can
sometimes also mask and make worse a genetic heart defect that puts
people at increased risk of sudden cardiac death, which has been
identified as the cause of death for several pro players in recent
Still, many medical experts say the greatest risk for big men like
football linemen and basketball centers probably doesn't confront them
while they're still playing, but later on, after they stop.
"Guys in their 20s and 30s can handle it, but by the time they're
in their late 30s and early 40s, they get a large amount of joint
pain, arthritis,'' said Dr. Shawn Bonsell, an orthopedic surgeon at
Baylor University's Medical Center in Dallas. "On the medical side of
things, it's even more serious -- diabetes and an elevated risk of
heart disease and heart attack.''
Contact Lee Bowman at BowmanL@SHNS.com