About Obesity
Causes of Morbid Obesity
The reasons for obesity are multiple and complex.
Despite conventional wisdom, it is not simply
a result of overeating. Research has shown that
in many cases a significant, underlying cause
of morbid obesity is genetic. Studies have demonstrated
that once the problem is established, efforts
such as dieting and exercise programs have a limited
ability to provide effective long-term relief.
Science continues to search for answers. But
until the disease is better understood, the control
of excess weight is something patients must work
at for their entire lives. That is why it is very
important to understand that all current medical
interventions, including weight loss surgery,
should not be considered medical cures. Rather
they are tools to reduce the effects of excessive
weight and alleviate the serious physical, emotional
and social consequences of the disease.
Contributing Factors
Genetic Factors
The Pima Paradox
Environmental Factors
Metabolism
Eating Disorders & Medical
Conditions
Contributing Factors
The underlying causes of severe obesity are not
known. There are many factors that contribute to
the development of obesity including genetic, hereditary,
environmental, metabolic and eating disorders. There
are also certain medical conditions that may result
in obesity like intake of steroids and hypothyroidism.
Genetic Factors
Numerous scientific studies have established
that your genes play an important role in your
tendency to gain excess weight.
- The body weight of adopted children shows
no correlation with the body weight of their
adoptive parents, who feed them and teach them
how to eat. Their weight does have an 80 percent
correlation with their genetic parents, whom
they have never met.
- Identical twins, with the same genes, show
a much higher similarity of body weights than
do fraternal twins, who have different genes.
- Certain groups of people, such as the Pima
Indian tribe in Arizona, have a very high incidence
of severe obesity. They also have significantly
higher rates of diabetes and heart disease than
other ethnic groups.
We probably have a number of genes directly related
to weight. Just as some genes determine eye color
or height, others affect our appetite, our ability
to feel full or satisfied, our metabolism, our
fat-storing ability, and even our natural activity
levels.
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The Pima Paradox
The Pima Indians are known in scientific circles
as one of the heaviest groups of people in the
world. In fact, National Institutes of Health
researchers have been studying them for more than
35 years. Some adults weigh more than 500 pounds,
and many obese teenagers are suffering from diabetes,
the disease most frequently associated with obesity.
But here's a really interesting fact - a group
of Pima Indians living in Sierra Madre, Mexico,
does not have a problem with obesity and its related
diseases. Why not?
The leading theory states that after many generations
of living in the desert, often confronting famine,
the most successful Pima were those with genes
that helped them store as much fat as possible
during times when food was available. Now those
fat-storing genes work against them.
Though both populations consume a similar number
of calories each day, the Mexican Pima still live
much like their ancestors did. They put in 23
hours of physical labor each week and eat a traditional
diet that's very low in fat. The Arizona Pima
live like most other modern Americans, eating
a diet consisting of around 40 percent fat and
engaging in physical activity for only two hours
a week.
The Pima apparently have a genetic predisposition
to gain weight. And the environment in which they
live - the environment in which most of us live
- makes it nearly impossible for the Arizona Pima
to maintain a normal, healthy body weight.
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Environmental Factors
Environmental and genetic factors are obviously
closely intertwined. If you have a genetic predisposition
toward obesity, then the modern American lifestyle
and environment may make controlling weight more
difficult.
Fast food, long days sitting at a desk, and suburban
neighborhoods that require cars all magnify hereditary
factors such as metabolism and efficient fat storage.
For those suffering from morbid obesity, anything
less than a total change in environment usually
results in failure to reach and maintain a healthy
body weight.
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Metabolism
We used to think of weight gain or loss as only
a function of calories ingested and then burned.
Take in more calories than you burn, gain weight;
burn more calories than you ingest, lose weight.
But now we know the equation isn't that simple.
Obesity researchers now talk about a theory called
the "set point," a sort of thermostat
in the brain that makes people resistant to either
weight gain or loss. If you try to override the
set point by drastically cutting your calorie
intake, your brain responds by lowering metabolism
and slowing activity. You then gain back any weight
you lost.
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Eating Disorders &
Medical Conditions
Weight loss surgery is not a cure for eating
disorders. And there are medical conditions, such
as hypothyroidism, that can also cause weight
gain. That's why it's important that you work
with your doctor to make sure you do not have
a condition that should be treated with medication
and counseling.
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