Obesity
Medical Author: Ruchi Mathur, MD
Medical Editor: Dennis Lee, MD
What is obesity?
The definition of obesity varies depending on what one reads, but in general,
it is a chronic condition defined by an excess amount body fat. A certain amount
of body fat is necessary for storing energy, heat insulation, shock absorption,
and other functions. The normal amount of body fat (expressed as percentage of
body fat) is between 25-30% in women and 18-23% in men. Women with over 30% body
fat and men with over 25% body fat are considered obese.
How common is obesity?
Obesity has reached epidemic proportions in the United States. One in three
Americans is obese. Obesity is also increasing rapidly throughout the world, and
the incidence of obesity has nearly doubled form 1991 to 1998.
Being Overweight Doesn't Mean You're Unhealthy!
Medical Author: Benjamin C. Wedro, MD, FAAEM
Medical Editor: Melissa Conrad Stöppler, MD
 The results of a study published in the Archives of Internal Medicine should
not come as a shock to most people. Being overweight doesn't necessarily make
you unhealthy, according to researchers in both the United States and Germany.
Sports fans have known this forever; elite athletes can have an appearance
ranging from tiny Olympic gymnasts to massive NFL linemen. Athletes at both
extremes- and all those in between- are in shape and trained to perform at high
levels.
The new research confirmed this. People who are
overweight have a fifty-fifty
chance of having high cholesterol, high blood pressure, or elevated blood sugar
levels. Pretty good odds, but not as good as those for people who are within the
normal weight range. They have a 75% chance of having normal results on blood
tests for cholesterol and blood sugar. And for those who are obese, the chance
of having normal results falls to one-third.
The definition of "ideal body weight" has been a thorn in the side of many
people. Perceptions of how people appear, how their clothes fit, and how fat
they are have permitted whole industries to flourish. Weight loss clinics, gyms
and fitness centers, liposuction, and
gastric bypass surgeries all were based
at least partly on the presumption that being overweight equaled being at risk
for heart disease and diabetes. The studies in the
Archives of Internal Medicine
found that there may be more to health than meets the eye.
What are the health risks associated with obesity?
Obesity is not just a cosmetic consideration; it is a dire health dilemma
directly harmful to one's health. In the United States, roughly 300,000 deaths
per year are directly related to obesity, and more than 80% of these deaths are
in patients with a BMI (body mass index, which will be discussed later in this
article) over 30. Obesity also increases the risk of developing a number of
chronic diseases including:
- Insulin Resistance. Insulin is necessary for the transport of blood
glucose (sugar) into the cells of muscle and fat (which is then used for
energy). By transporting glucose into cells, insulin keeps the blood glucose
levels in the normal range. Insulin resistance (IR) is the condition whereby the
effectiveness of insulin in transporting glucose (sugar) into cells is
diminished. Fat cells are more insulin resistant than muscle cells; therefore,
one important cause of IR is obesity. The pancreas initially responds to IR by
producing more insulin. As long as the pancreas can produce enough insulin to
overcome this resistance, blood glucose levels remain normal. This IR state
(characterized by normal blood glucose levels and high insulin levels) can last
years. Once the pancreas can no longer keep up with producing high levels of
insulin, blood glucose levels begin to rise, resulting in type 2 diabetes, thus
IR is a pre-diabetes condition. In fact scientists now believe that the
atherosclerosis (hardening of the arteries) associated with diabetes likely
develops during this IR period.
- Type 2 (adult-onset) diabetes. The risk of type 2 diabetes increases with
the degree and duration of obesity. Type 2 diabetes is associated with central
obesity; a person with central obesity has excess fat around his/her waist, so
that the body is shaped like an apple.
- High blood pressure (hypertension). Hypertension is common among obese
adults. A Norwegian study showed that weight gain tended to increase blood
pressure in women more significantly than in men. The risk of developing high
blood pressure is also higher in obese people who are apple shaped (central
obesity) than in people who are pear shaped (fat distribution mainly in hips and
thighs).
- High cholesterol (hypercholesterolemia)
- Stroke (cerebrovascular accident or CVA)
- Heart attack. The Nurses Health Study found that the risk of developing
coronary artery disease increased 3 to 4 times in women who had a BMI greater
than 29. A Finnish study showed that for every one kilogram (2.2 pounds)
increase in body weight, the risk of death from coronary artery disease
increased by one percent. In patients who have already had a heart attack,
obesity is associated with an increased likelihood of a second heart attack.
- Cancer. While not conclusively proven, some observational studies have
linked obesity to cancer of the colon in men and women, cancer of the rectum and
prostate in men, and cancer of the gallbladder and uterus in women. Obesity may
also be associated with breast cancer, particularly in postmenopausal women. Fat
tissue is important in the production of estrogen, and prolonged exposure to
high levels of estrogen increases the risk of breast cancer.
- Osteoarthritis (degenerative arthritis) of the knees, hips, and the lower
back
- Pickwickian syndrome (obesity, red face, underventilation, and drowsiness)
Next: What causes obesity? »
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From the Doctors at MedicineNet.com  |
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- Tummy Tuck ( Abdominoplasty) - Abdominoplasty, (tummy tuck) is one of the more common cosmetic surgeries. This procedure flattens your abdomen by removing extra fat and skin, and tightening muscles in your abdominal wall. Source:WebMD Medical Reference from The Cleveland Clinic
- C-Reactive Protein Test (CRP) - Learn about your heart disease risk and how the CRP test can be a marker of the inflammation of arteries. Source:WebMD Medical Reference from The Cleveland Clinic
- Liposuction - liposuction involves the surgical suctioning of fat deposits from specific parts of the body, the most common being the abdomen (the "tummy"), buttocks ("behind"), hips, and thighs. Source:WebMD Medical Reference from The Cleveland Clinic
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