OVERWEIGHT AND OBESITY
Obesity is a chronic, metabolic disease
caused by multiple and complex inherited and acquired factors,
including excessive calorie and food intake, decreased physical
activity, and genetic influences. The defining characteristic is
excess body fat.
Long-term treatment and management are
required to achieve and sustain weight loss. Obesity,
particularly when associated with unhealthy patterns of body fat
distribution, results in 300,000 preventable deaths each year in
the U.S. and $100 billion in health care costs.
Causes of Obesity
An excess of body fat results from an
imbalance between energy intake and energy output (i.e.,
consuming more calories than are needed to support your body's
energy needs). Factors that promote obesity include genes,
family history of obesity, behavioral factors (such as a high
fat diet and sedentary lifestyle), and biochemical differences
(lower metabolic rate or decreased ability to oxidize fat).
It can be difficult to measure accurately
the proportion of a person's body that is composed of fat.
However, an accepted indicator of obesity and its risks is the
Body Mass Index (BMI), which takes into account body
weight and height. To calculate your BMI number, divide your
weight in kilograms by your height in meters squared.
A BMI of 30 suggests obesity. A BMI of 25
means that you are "overweight." In Asians, a lower BMI of 22
indicates overweight, and BMI of 25 indicates obesity.
Checking skinfold thickness and
bioelectrical impedance are two other methods of measuring
fatness. These tests help to differentiate between weight that
is attributable to fat accumulation and weight that represents
A number of conditions worsen as obesity
increases and often improve as obesity is successfully treated.
Some of these conditions are:
Cardiovascular (heart) disease
High blood pressure
Type 2 diabetes
Elevated blood cholesterol and triglyceride levels
Sleep apnea/obesity hypoventilation syndrome
Osteoarthritis of the weight bearing joints
Obesity also increases the risk for
developing some forms of cancer (i.e., breast, colorectal).
Scientific studies show that upper body
obesity, particularly excess fat within the abdominal cavity
(visceral fat), increases health risks more than fat
accumulation in the lower body (hips and thighs). Higher
proportions of visceral fat are associated with higher risks of
insulin resistance, diabetes, high blood pressure and
atherosclerosis , leading to cardiovascular disease (heart
disease and strokes).
How can you
estimate your body fat distribution?
Look at yourself in the mirror. If you are
more apple-shaped than pear-shaped, you probably have visceral
fat accumulation. A more precise approach is to use the
Waist/Hip (WHR) ratio. For women, visceral fat accumulation
is indicated by a WHR greater than 0.8. For a man, visceral fat
accumulation is indicated by a WHR greater than 1.0. A newer
measurement uses only the waist circumference.
There is an abundance of clinical data
showing that losing as little as five to ten percent of body
weight and maintaining that loss can significantly improve the
health of obese patients. For that reason, persons who are
diagnosed as being clinically obese should seek treatment. The
principal phases of treatment are:
1) stopping weight gain
2) reducing weight to a level that diminishes the health risk to
3) maintaining weight at the lower level
4) improving your diet
5) being physically more active
6) improving health care practices
What can I do?
The following would help:
lower calorie diets
increased physical activity
drug therapies to enhance the weight loss process
surgery (for every obese individuals)
Sibutramine (Reductil or Meridia)
increases the levels of both serotonin and noradrenaline in
areas of the brain that regulate food intake and body weight. It
reduces some complications of obesity, such as those
involving blood glucose and lipids. The side-effects may include
dry mouth, lethargy, drowsiness, and insomnia.
Orlistat (Xenical) is unique among
current obesity drugs in that it does not act directly on the
central nervous system. It inhibits and enzyme (pancreatic
lipase) essential to fat digestion. The most common side effects were
intestinal symptoms, including cramping, gas and diarrhea -
particularly in patients who ate high-fat foods against their
Duromine acts on the brain to
produce a sensation of fullness (satiety). Common side effects are
dry mouth, insomnia and constipation.
All these medications are approved by the
FDA and Singapore's Health Sciences Authority.
Types of Obesity
Several procedures have been proven to help
promote significant weight loss. These include stapling the
stomach or banding the stomach to make it smaller, gastric
bypass operations, jaw wiring. Contrary to popular belief,
liposuction, the most frequent cosmetic operation in the United
States in which fat tissue is removed, seldom succeeds in
leading to significant weight loss. Successful obesity surgery
may lead to a loss of up to 60% of excess weight mostly in the
first year and often continuing up to 5 years.
slimming centers, lifestyle centers and herbal supplements?
Beware of seductive advertising in the
media. None of
these approaches have been shown scientifically to be effective
or safe. Women patients are often the target of unscrupulous