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| Obesity-A Global Epidemic |
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About
Obesity
Overweight
and Obesity
Causes of
Obesity
Effects
of Obesity |
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| About
Obesity |
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 Though
we all use the terms "fat" and "obese"
casually in conversation, there is a medical definition
of the condition and yes, obesity is considered a health
"condition." It is a term used to describe
body weight that is much greater than what is considered
healthy. Measuring the exact amount of a person's body
fat is not easy. The most accurate measures are to weigh
a person underwater or in a chamber that uses air displacement
to measure body volume, or to use an X-ray test called
Dual Energy X-ray Absorptiometry, also known as DEXA.
These methods are not practical for the average person,
and are done only in research centers with special equipment.
There are also other ways to determine if a person
is obese, but experts believe that a person's body mass
index (BMI) is the most accurate measurement of body
fat for children and adults. Adults with a BMI greater
than 30 are considered obese. You will be surprised
to know that nearly one-thirds of the world's population
is overweight. Rates of obesity are climbing. The percentage
of children who are overweight has doubled in the last
20 years. The percentage of adolescents who are obese
has tripled in the last 20 years. Morbid obesity is
typically defined as being 100 pounds or more over ideal
body weight or having a BMI of 40 or higher. Obesity
becomes "morbid" when it significantly increases
the risk of one or more obesity-related health conditions
or serious diseases (also known as co-morbidities).
According to the NIH Consensus Report, morbid obesity
is a serious chronic disease, meaning that its symptoms
build slowly over an extended period of time. Today
97 million Americans, more than one-third of the adult
population, are overweight or obese. An estimated 5-10
million of those are considered morbidly obese.
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W.H.O. CLASSIFICATION
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BMI
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| Ideal
weight |
20-24.9 |
| Overweight |
25-29.9 |
| Moderate
obesity (class I) |
30-34.9 |
| Severe
obesity (class II) |
35-39.9 |
| Morbid
obesity (class III) |
40-49.9 |
| Super
obesity |
50 + |
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| Overweight
and obesity |
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| Overweight and obesity are both labels
for ranges of weight that are greater than what is generally
considered healthy for a given height. For adults, overweight
and obesity ranges are determined by using weight and
height to calculate a number called the "body mass
index" (BMI). BMI is used because, for most people,
it correlates with their amount of body fat. |
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- An adult who has a BMI between 25 and 29.9 is considered
overweight.
- An adult who has a BMI of 30 or higher is considered
obese.
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| See the following table for an example. |
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Height
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Weight Range
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BMI
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Considered
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5' 9"
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124 lbs or less
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Below 18.5
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Underweight
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125 lbs to 168 lbs
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18.5 to 24.9
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Healthy weight
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169 lbs to 202 lbs
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25.0 to 29.9
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Overweight
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203 lbs or more
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30 or higher
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Obese
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It is important to remember that although
BMI correlates with the amount of body fat, BMI does not
directly measure body fat. As a result, some people, such
as athletes, may have a BMI that identifies them as overweight
even though they do not have excess body fat. Other methods
of estimating body fat and body fat distribution include
measurements of skin fold thickness and waist circumference,
calculation of waist-to-hip circumference ratios, and
techniques such as ultrasound, computed tomography, and
magnetic resonance imaging (MRI).
The obesity epidemic covered on TV and in the newspapers
did not occur overnight. Obesity and overweight are chronic
conditions. Obesity has already 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. Overall there are a variety of factors that play
a role in obesity. This makes it a complex health issue
to address. |
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| Causes
of obesity |
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Overweight and obesity are a result
of energy imbalance over a long period of time. The cause
of energy imbalance for each individual may be due to
a combination of several factors. Obesity occurs when
a person consumes more calories from food than he or she
burns. Our bodies need calories to sustain life and be
physically active, but to maintain weight we need to balance
the energy we eat with the energy we use. When a person
eats more calories than he or she burns, the energy balance
is tipped toward weight gain and obesity. This imbalance
between calories-in and calories-out may differ from one
person to another. If you look carefully at the energy
balance scale ( given below), weight gain is a result
of extra calorie consumption, decreased calories used
(reduced physical activity) or both. Personal choices
concerning calorie consumption and physical activity can
lead to energy imbalance.
In most cases, obesity results from genetic, environmental
and psychological factors. But sometimes certain illnesses
can also lead to weight gain or obesity, e.g. endocrine
disorders (such as hypothyroidism and Cushing's syndrome)
or neurological problems. In addition to this, certain
drugs such as steroids and some antidepressants, can lead
to either weight gain or increased appetite. Let us discuss
these causes in details now: |
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| Lifestyle Habits |
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Today, a changing environment has
broadened food options and eating habits. Grocery stores
stock their shelves with a greater selection of products.
Pre-packaged foods, fast food restaurants, and soft drinks
are also more accessible. While such foods are fast and
convenient they also tend to be high in fat, sugar, and
calories. Choosing many foods from these areas may contribute
to an excessive calorie intake. This results in increased
calorie consumption. If the body does not burn off the
extra calories consumed from larger portions, fast food,
or soft drinks, weight gain can occur.
Our bodies need calories for daily functions such as breathing,
digestion, and daily activities. Weight gain occurs when
calories consumed exceed this need. Physical activity
plays a key role in energy balance because it uses up
calories consumed. Despite all the benefits of being physically
active, most of us are sedentary. Technology has created
many time and labour saving products. Some examples include
cars, elevators, washing machines, dishwashers, and televisions.
Cars are used to run short distance errands instead of
people walking or riding a bicycle. As a result, these
recent lifestyle changes have reduced the overall amount
of energy expended in our daily lives. According to the
Behavioural Risk Factor Surveillance System, in 2000 more
than 26% of adults reported no leisure time physical activity.
The belief that physical activity is limited to exercise
or sports, may keep people from being active. Another
myth is that physical activity must be vigorous to achieve
health benefits. Physical activity is any bodily movement
that results in an expenditure of energy. But when we
fail to do any physical activity, it just leads to calorie
storage. |
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| Environment |
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 People
may make decisions based on their environment or community.
For example, a person may choose not to walk to the store
or to work because of a lack of sidewalks. Communities,
homes, and workplaces can all influence people's health
decisions. Because of this influence, it is important
to create environments in these locations that make it
easier to engage in physical activity and to eat a healthy
diet.
Genetics
Obesity tends to run in families, suggesting a genetic
cause. However, families also share diet and lifestyle
habits that may contribute to obesity. Separating genetic
from other influences on obesity is often difficult. Even
so, science does show a link between obesity and heredity.Genes
can directly cause obesity in disorders such as Bardet-Biedl
syndrome and Prader-Willi syndrome. |
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| Drugs |
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| Some illnesses may lead to obesity
or weight gain. These may include Cushing's disease, and
polycystic ovary syndrome. Drugs such as steroids and
some antidepressants may also cause weight gain. A doctor
is the best source to tell you whether illnesses, medications,
or psychological factors are contributing to weight gain
or making weight loss hard. |
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| Certain illnesses |
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| In addition, some illnesses may lead
to or are associated with weight gain or obesity, e.g
Hypothyroidism, a condition in which the thyroid gland
fails to produce enough thyroid hormone. It often results
in lowered metabolic rate and gain in weight. Another
example is Cushing's syndrome. These kind of underlying
medical conditions either make weight loss difficult or
contribute to weight gain. |
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| Effects
of obesity |
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| Severe obesity damages the body mechanically,
metabolically, physiologically and has adverse effects
on normal bodily function. This affects nearly every organ
in the body in some way, and produce serious secondary
illnesses, which may also be life-threatening. The cumulative
effect of these co-morbidities can interfere with a normal
and productive life, cause endless frustration and can
seriously shorten life, as well. Some of the consequences
of obesity have been given below: |
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Obesity is considered as 2nd leading
cause of preventable death
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Heart Disease
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| Severely obese persons are approximately
6 times as likely to develop heart disease as those who
are normal-weighted. Heart disease is the leading cause
of death in the United States today, and obese persons
tend to develop it earlier in life, and it shortens their
lives. Coronary disease is pre-disposed by increased levels
of blood fats, and the metabolic effects of obesity. Increased
load on the heart leads to early development of congestive
heart failure. Severely obese persons are 40 times as
likely to suffer sudden death, in many cases due to cardiac
rhythm disturbances. |
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High Blood Pressure
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| Essential hypertension, the progressive
elevation of blood pressure, is much more common in obese
persons, and leads to development of heart disease, and
damage to the blood vessels throughout the body, causing
susceptibility to strokes, kidney damage, and hardening
of the arteries. |
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High Blood Cholesterol
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| Cholesterol levels are commonly elevated
in the severely obese -- another factor predisposing to
development of heart and blood vessel disease. This abnormality
is not just related to diet, but is an effect of the massive
imbalance in body chemistry which obesity causes. |
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Diabetes Mellitus
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| Overweight persons are 40 times as
likely to develop Type II, Adult-Onset, and Diabetes.
Elevation of the blood sugar, the essential feature of
Diabetes, leads to damage to tissues throughout the body:
Diabetes is the leading cause of adult-onset blindness,
a major cause of kidney failure, and the cause of over
one half of all amputations. |
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Sleep Apnoea Syndrome
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| Sleep apnoea -- the stoppage of breathing
during sleep is commonly caused in the obese, by compression
of the neck, closing the air passage to the lungs. It
leads to loud snoring, interspersed with periods of complete
obstruction, during which no air gets in at all. The sleeping
person sounds to an observer like he is holding his breath,
but the sleeper is, himself, usually unaware that the
problem is occurring at all, or only notices that he sleeps
poorly, and awakens repeatedly during the night. The health
effects of this condition may be severe, high blood pressure,
cardiac rhythm disturbances, and sudden death. |
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Respiratory problems
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| Obese persons find that exercise causes
them to be out of breath very quickly, during ordinary
activities. The lungs are decreased in size, and the chest
wall is very heavy and difficult to lift. At the same
time, the demand for oxygen is greater, with any physical
activity. This condition prevents normal physical activities
and exercise, often interferes with usual daily activities,
making even ordinary living difficult or miserable, and
it can become completely disabling.
Obesity is associated with a higher rate of asthma,
about 3 times normal. Much of this effect is probably
due to acid reflux which can irritate a sensitive airway
and provoke an asthmatic attack.
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Gallbladder Disease
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| Gallbladder disease occurs several
times as frequently in the obese, in part due to repeated
efforts at dieting, which predispose to this problem.
When stones form in the gallbladder, and cause abdominal
pain or jaundice, the gallbladder must be removed. |
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Stress Urinary Incontinence
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| A large heavy abdomen, and relaxation
of the pelvic muscles, especially associated with the
effects of childbirth, may cause the valve on the urinary
bladder to be weakened, leading to leakage of urine with
coughing, sneezing, or laughing. This condition is strongly
associated with being overweight, and is usually relieved
by weight loss. |
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Degenerative Disease of Lumbo-Sacral Spine
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| The entire weight of the upper body
falls on the base of the spine, and overweight causes
it to wear out, or to fail. The consequence may be accelerated
arthritis of the spine, or "slipped disk", when
the cartilage between the vertebrae squeezes out. Either
of these conditions can cause irritation or compression
of the nerve roots, and lead to sciatica -- a dull, intense
pain down the outside of the leg. |
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Degenerative Arthritis of Weight-Bearing Joints
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| The hips, knees, ankles and feet have
to bear most of the weight of the body. These joints tend
to wear out more quickly, or to develop degenerative arthritis
much earlier and more frequently, than in the normal-weighted
person. Eventually, joint replacement surgery may be needed,
to relieve the severe pain. Unfortunately, the obese person
faces a disadvantage there too -- joint replacement has
much poorer results in the obese, and complications are
more likely. Many orthopedic surgeons refuse to perform
the surgery in severely overweight patients |
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Venous Stasis Disease
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| The veins of the lower legs carry
blood back to the heart, and they are equipped with an
elaborate system of delicate one-way valves, to allow
them to carry blood "uphill". The pressure of
a large abdomen may increase the load on these valves,
eventually causing damage or destruction. The blood pressure
in the lower legs then increases, causing swelling, thickening
of the skin, and sometimes ulceration of the skin. Blood
clots also can form in the legs, further damaging the
veins, and can also break free and float into the lungs
-- called a Pulmonary Embolism -- a serious or even fatal
event. |
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Emotional/Psychological Disease
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| Seriously overweight persons face
constant challenges to their emotions: repeated failure
with dieting, disapproval from family and friends, sneers
and remarks from strangers. They often experience discrimination
at work, and cannot enjoy theatre seats, or a ride in
a bus or airliner. There is no wonder that anxiety and
depression might accompany years of suffering from the
effects of a genetic condition -- one which skinny people
all believe should be controlled easily by will power. |
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Social Effects
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| Seriously obese persons suffer inability
to qualify for many types of employment, and discrimination
in employment opportunities, as well. They tend to have
higher rates of unemployment, and a lower socioeconomic
status. Ignorant persons often make rude and disparaging
comments, and there is a general societal belief that
obesity is a consequence of a lack of self-discipline,
or moral weakness. Many severely obese persons find it
preferable to avoid social interactions or public places,
choosing to limit their own freedom, rather than suffer
embarrassments. |
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| Facts about Morbidity due to untreated
Obesity |
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- Heart and Stroke foundation research shows
that the number of deaths attributable
directly to overweight and obesity has almost
doubled over the last 15 yrs
- 4,321 deaths in the year 2000 alone
- US-based studies indicated that obese individuals
can lose more than 10 years of
life compared to their normal weight peers
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