|
Without the surgery, her mother could
die within the year because obesity is escalating her lung problems
and causing many other conditions, such as diabetes and sleep apnea.
This woman also believes her obesity is
a disease, but is she right? Is obesity on a par with diabetes? Or
is obesity a risk factor that leads to illnesses?
These questions are the center of
controversy among doctors, health advocates, insurance companies and
others. And the answers could have long-range implications,
particularly for insurance coverage of certain treatments for
obesity.
"I think obesity meets all of the
criteria of a chronic disease," said Richard L. Atkinson, president
of the American Obesity Association. "But it's not a single disease;
it's not monolithic. It's a collection of diseases."
The crux of the matter, Atkinson said,
is that obese people have a different biochemistry than thin people
-- an abnormal biochemistry that meets the definition of disease.
What obese people share in common,
according to Atkinson, is "an abnormality of sensing excess energy
stores." To explain, he said that when obese people lose a
significant amount of weight, the enzymes in the body that store fat
in the adipose tissue (fat tissue) go up. The body goes into a
starvation mode, which means that most of the fat coming into the
body goes directly into storage in the fat cells instead of being
burned. The body doesn't sense that there is already plenty of
excess fat being stored in the adipose tissue.
In contrast to the skinny person,
Atkinson said, "You're now poised so that any extra molecule of fat
that comes in gets stored. It doesn't get burned. You eat a few
extra calories and wham! It gets stored in the fat cells because the
biochemistry is not the same as a person who has never been obese.
So the biochemistry favors gaining weight."
Donald Layman, a professor in the
University of Illinois Department of Food Science and Human
Nutrition, agrees that individuals have different metabolic
efficiencies; they burn and store fat at different rates. But he
said truly abnormal metabolisms are rare, affecting about 1 percent
of obese subjects.
For the vast majority, Layman said,
obesity is pure physiology. "Obesity has a lot of clinical pathology
and negative outcomes," he said. "But my problem in considering it a
disease is that I view obesity as a normal, expected outcome in an
environment in which we eat too much and exercise too little."
If someone is obese at a young age, he
said, there could be an inherent abnormality. "But when you find
progressive weight gain over two or three decades at the rate of two
or three pounds per year, that's not genetic. That's a
calorie-balance issue."
However, Layman agreed that severe
obesity can be difficult to correct.
[to top of second column
in this article] |
"If you take an individual and they
become 20 percent overweight, can you correct that?" he asked. "I
think you can. But if you take a 200-pound person and they go up to
400 pounds, can you correct that? Chances are that person has
developed new fat cell populations. And most of the data suggest
that once you develop new fat cell populations, you're not going to
get rid of them easily."
But this level of obesity is not what's
being seen in the population, he pointed out. "Everybody's not
walking around at 400-plus pounds. Most are walking around at
weights like 280."
Although Layman believes that
overeating and under-exercising are behind most obesity, he said it
doesn't work to simply say, "You're obese. Fix it." Making major
changes is particularly tough in an environment where people work
sedentary jobs, buy supersized meals and are encouraged to clean
their plate no matter how much food is on it.
"In our environment, the profit
incentive is that if I can give you bigger portion sizes, I can
charge more money," Layman said. "If I can supersize it, I can make
more money, and I don't care if you're overweight."
With bigger portion sizes, customers
feel they are getting more bang for their buck. But in reality,
they're simply getting more calories for their cash.
The question of whether obesity is the
result of disease or an environment that promotes overeating (or
both) is not just a matter of semantics. Some argue that defining it
as disease would open the door for insurance coverage of drugs and
treatments for obesity. But others argue that it would open that
door too wide, causing insurance premiums to skyrocket.
Another issue is whether labeling
obesity a disease would de-stigmatize the condition or whether it
would send the wrong message by implying that overcoming obesity is
out of a person's control.
However those questions are answered,
Layman said one thing is certain. The dramatic increase in obesity
over the past three decades is evidence that the trends are not
being driven by genetics. The number of overweight adults in the
United States increased from 46 to 64 percent between 1976 and 1999,
while the number of obese adults increased from 14 to 30 percent.
"If you think it's genetic, we would
have to have had a major change in the gene pool in the last 30
years," Layman noted.
Atkinson agrees that genetics obviously
haven't changed in one generation, while "the environment has
clearly changed," but he thinks these environmental changes have
acted on the genetic predispositions of different people in
different ways.
In other
words, as he put it, "If you're destined to be thin, it's really
hard to get fat. And if you're destined to be fat, it's really hard
to stay skinny. If you are thin, thank your lucky stars and your
parents."
[University of Illinois news release]
|
