|
Why the Doctor Asks You to Lose
Weight
If your doctor asks you to lose
weight, it's because he or she is concerned about your
health. Obesity can increase your risk of health problems.
You're far more likely to have high blood pressure, heart
disease and diabetes. If you have arthritis, excess weight
can make movement more painful.
Your doctor can use one of two scientific assessment tools
to see if you're obese. Obesity is determined by
percentage of body fat and weight. Having a large percentage
of body fat, regardless of how much you weigh, is unhealthy.
You could be of normal weight or underweight and still have
an unhealthy amount of body fat. Being overweight means that
you have a heavy weight, but not necessarily too much body
fat. People who are muscular weigh more than those who are
not; their extra weight comes from muscle, not body fat.
According to guidelines by the National Heart, Blood and Lung
Institute (NHLBI), an assessment of whether you are
overweight involves using three key measures:
-
Body mass index (BMI)
-
Waist circumference
-
Risk factors for diseases and conditions associated with
obesity, which include high blood pressure, high level of
LDL cholesterol, high triglycerides, high blood sugar and
smoking.
Body mass index
The first measurement involves
determining your body mass index, or BMI. You can calculate it
yourself. Multiply your weight in pounds by 704, then divide by
the square of your height in inches.
For example, if you weigh 162 pounds and are 69 inches tall,
your BMI is 23.9, or (162 x 704) ÷ (69 x 69), and is
normal.
-
A BMI of 18 or below: Underweight
-
A BMI of 19 to 24: Normal
-
A BMI of 25 to 29: Overweight
-
A BMI of 30 or greater: Obese
For people who are considered obese or
those who are overweight and have two or more risk factors, the
NHLBI guidelines recommend losing weight.
Although BMI is a reliable indicator of total body fat, it does
have some limits. It may overestimate body fat in athletes and
others with a muscular build. It may underestimate body fat in
older adults and in others who have lost muscle mass.
Abdominal fat/waist
circumference
The second indicator measures abdominal
fat and predicts the risk of diseases associated with obesity.
You can determine your waist circumference by placing a
measuring tape snugly around your waist. Your waist
circumference is a good indicator of your abdominal fat. Your
risk of obesity-related diseases increases with a waist
measurement of more than 40 inches in men and more than 35
inches in women.
Your doctor will probably use your abdominal fat measurement
along with your BMI to assess your risk. People who are
overweight (BMI of 25 to 29.9), but don't have a large waist
measurement and have fewer than two risk factors may need only
to prevent additional weight gain rather than to lose
weight.
Reducing body weight by as little as 10 percent may greatly
decrease your risk for developing heart disease or other health
complications.
Alternative means
Your doctor can also determine whether
you are obese or overweight by measuring your skin fold
thickness. This measurement, called anthropometry, is taken
around the triceps, on the shoulder blades and on the hips. The
results can determine whether your weight is from muscle or from
fat.
Other ways your doctor may determine if you're overweight
include consulting height and weight tables and considering your
body frame size.
The National Library of Medicine explains these
methods.
-
Women: 100 pounds of body weight for the first 5
feet of height, 5 pounds for each additional inch.
-
Men: 106 pounds for the first 5 feet of height, 6
pounds for each additional inch.
-
Add 10 percent for a large frame size; subtract 10 percent
for a small frame size.
Determine frame size by measuring the
wrist and using the following information. Like the height and
weight tables, it's also gender-specific.
-
For women under 5 feet, 2 inches:
-
Small frame: wrist smaller than 5.5 inches
-
Medium frame: wrist 5.5 inches to 5.75 inches
-
Large frame: wrist larger than 5.75 inches
-
Women 5 feet, 2 inches to 5 feet, 5 inches:
-
Small frame: wrist smaller than 6 inches
-
Medium frame: wrist 6 inches to 6.25 inches
-
Large frame: wrist larger than 6.25 inches
-
Women taller than 5 feet, 5 inches:
-
Small frame: wrist smaller than 6.25 inches
-
Medium frame: wrist size 6.25 inches to 6.5
inches
-
Large frame: wrist larger than 7.5 inches
-
Men taller than 5 feet, 5 inches:
-
Small frame: wrist smaller than 6.5 inches
-
Medium frame: wrist size 6.5 inches to 7.5
inches
-
Large frame: wrist size larger than 7.5 inches
Using these methods, the percent over the ideal weight
determines how overweight one might be. Calculate it by taking
the difference between the actual weight and the ideal weight
and dividing it by the ideal weight, then multiplying by
100.
Taking a 150-pound woman as an example:
-
Ideal weight of 125 pounds
-
Actual weight of 150 pounds
-
Find the difference: 150-125 = 25
-
Multiply that result by 100: 25/125 x 100 = 20 percent
overweight
|
