Overview
Over the years, healthcare providers and
consumers have had trouble defining who is fat, overweight or obese.
To make matters worse, some people remain confused about these
terms, and still use them interchangeably. In an effort to clarify
these terminologies and provide scientific guidelines for the
medical management of individuals with excess weight, in 1998, the
National Heart, Lung and Blood Institute (NHLBI), in collaboration
with the National Institute of Diabetes, Digestive and Kidney
Disease (NIDDK), established the first Federal guidelines on the
identification, evaluation and treatment of overweight and obesity
in adts. These clinical practice guidelines are designed to help
healthcare providers in their care of the obese and overweight.
These two public health problems are believed to affect about 100
million American adults, a figure that translates into approximately
one out of every three Americans!
From these guidelines, being overweight, and
obesity are defined using a new parameter called the Body
Mass Index (BMI). The body mass index describes
one’s body weight relative to height, and is believed to strongly
correlate with the total body fat content in adults, hence the
emphasis on this parameter. Adding more weight to the significance
of BMI, is the recent finding that, as an independent marker, it
correlates with risk of death and illness in a given individual.
How do
you know if you are overweight or obese?
It is very easy to find out using the new
guidelines. First, you measure your weight in kilograms (note that
2.2Ibs equals 1kg). Then obtain your height in meters (1 inch equals
0.0254 meters). Calculating your BMI involves dividing your weight
in kg by the square of your height in meters. It is mathematically
expressed as follows;
BMI = weight in kilograms/height in meters x
height in meters.
Really, you do not need to know this formula to
figure your BMI. There are numerous programs and charts that can
match your weight and height and come up with the same information.
Using the recommended guidelines, the following definitions have
emerged;
- A person
with a BMI of 25-29.9 is considered overweight
- A person
with a BMI of 30 and above is obese
The cut-off point, a BMI of 25, represents the
threshold beyond which excess weight gain begins to pose significant
risk to an individual’s health. In fact, there is solid evidence to
suggest that the risk of cardiovascular (heart and blood vessel)
disorders and other diseases to be discussed later in this article
rises significantly when someone’s BMI exceeds 25. Therefore, the
new guidelines also call for periodic check of BMI in all adults
during their routine physical examinations. Individuals with normal
weight are encouraged to have their BMI reassessed every two
years.
Medical problems
associated with obesity
There is indeed a long list of medical conditions
associated with obesity. For some of the medical conditions, the
evidence linking them to obesity is overwhelming. As for other
diseases where the evidence may not be as strong, clinicians have
long known that weight reduction frequently improves the outlook for
patients. With this in mind, maintaining one’s ideal body weight
should be considered a life-long pursuit, since you almost always
have nothing to lose, in the immediate or long term, and a lot to
gain. It is important to note that for the following medical
conditions, the higher the BMI, the greater the risks.
- Type 2
Diabetes (formerly called adult onset diabetes) – It is believed
that with increasing weight gain, particularly when the BMI
exceeds 27, the body’s ability to respond to the hormone, insulin,
is compromised. When this happens, the glucose obtained from the
food we have eaten remains in the blood stream, unavailable for
the body’s cells, and diabetes results.
- Hypertension
– With increasing weight, the heart has to work harder to get
blood circulating all over the body, and this added strain can
lead to high blood pressure. In addition, the clogging of blood
vessels from associated cholesterol disorders impedes blood flow,
resulting in elevated blood pressure, independent of the excess
weight gain.
- Cholesterol
disorders and blood clots.
- Heart
Attacks and Angina – primarily due to the reasons alluded to
above.
- Stroke
(brain attack) – results from greater prevalence of high blood
pressure and clogged arteries in these individuals.
- Gallbladder
disease – because of increased risk of gallstones.
- Obstructive
Sleep Apnea, a medical condition in which affected individuals
stop breathing briefly and repeatedly during sleep. This usually
manifests as loud snoring, morning headache, tiredness, poor
concentration at work, and daytime excessive sleepiness. Although
also present in non-obese individuals, it is more common in the
overweight population, particularly those with a neck size greater
than 17.
- Breathing
problems other than sleep apnea.
- Certain
cancers such as colon cancer.
- Joint
problems, particularly the weight bearing joints such as the
knees, hips and spine.
Obesity and the
African-American population<
Although overweight and obesity remain a growing
public health problem for the entire nation, afflicting as much as
55% of the population, and imposing a $100 billion financial burden
annually, blacks are disproportionately affected by this epidemic.
Generally speaking, black folks in US are significantly heavier than
Whites, and some experts believe that this observation may well
explain why type 2 diabetes (adult onset diabetes) is so wide spread
within the African-American community. Besides diabetes, it is also
true that hypertension and stroke are more common in Blacks than
Whites. For all three conditions, having a BMI of 25 or greater
magnifies the risks. It makes sense to argue then that no group has
as much to gain from weight reduction strategies as the black
population does. There is no gainsaying the fact that if every
adult in the US, particularly blacks, commits to attaining a BMI of
less than 25, the health gains for the entire nation, as well as the
savings in dollars will be immeasurable.
Keeping the body
mass index less than 25
According to the new guidelines, to attain and
maintain a BMI less than 25 will require a multi-pronged approach,
depending on the individual’s baseline BMI. Basically, the accepted
treatment and preventive strategies for individuals who are
overweight or obese are all aimed at losing weight in a controlled
fashion. The initial goal of treatment should be to reduce body
weight by about 10 percent from baseline, an amount that is believed
to reduce obesity related risk. Subsequently, further weight loss
can be attempted – the goal being to attain ideal BMI (20 – 24). The
suggested safe duration of time to achieve this 10 percent reduction
from baseline weight is six months. If appropriate, further weight
loss should be one to two pounds per week. The strategy to achieve
the weight loss will, of course, depend on the patient’s baseline
weight and other co-existing medical conditions. Recommended
strategies for weight loss include:
- Calorie
reduction – individuals need to be aware that reducing dietary
fat alone, without cutting down on overall calorie intake will not
lead to weight loss. Consultation with nutrition experts will be
prudent
- Increased
physical activity – individuals cleared by their physicians to
engage in vigorous exercise, should engage in moderate physical
activity, for at least 30 minutes a day, and no less than 4 times
a week. For those with type 2 diabetes, exercise is an important
adjunct to medication in the control of their disease. In fact,
for individuals with a family history of type 2 diabetes
who have not yet developed the disease, regular exercise is the
most important “prescription” to prevent or delay the onset of
diabetes.
- Medications
– the key thing to remember here is not to take any
medications (over the counter ones included), without physician
supervision. It is dangerous to use a friend’s (or relative’s)
weight loss drugs without obtaining your physician’s approval. We
are all now familiar with Fen-Phen (the wonder drug for weight
loss) and the damage it causes to the heart. Also, drug therapy
should only be considered if lifestyle changes suggested above
have been tried for at least six months without appreciable
success. The risks of adverse effects from the drugs should be
balanced against the intended benefits. Bearing this in mind, drug
therapy will be worth the risks in patients with BMI greater than
30 without the additional risk factors or medical conditions noted
earlier, or BMI of 27 or greater with two or more of those
conditions. If drug therapy is considered an option, use only the
weight loss drugs approved by the Food and Drug Administration
(FDA). Usually, these drugs are not to be used for more than one
year.
- Weight
loss surgery – This most commonly refers to stomach stapling
to reduce the volume of the stomach, thus allowing satiety to be
reached early. This should be considered an option for carefully
screened individuals with severe obesity – defined as BMI of 40 or
greater or BMI of greater than 35 with co-existing conditions when
other measures outlined above have failed and the patient is at
significant risk for obesity-associated illness.
It must be mentioned
that of all the weight losing modalities noted above, calorie
reduction and increased physical activity have the best efficacy and
safety profile. A health club membership is safer and more cost
effective in the long run than medications or surgery. Also, unlike
diet and exercise, neither surgery nor medication can keep the
weight off over the long term.
Resources
For more
information on obesity, visit http://www.nhlbi.nih.gov/health/public/heart/obesity/lose_wt/index.htm
Obesity