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Clinically, obesity is described as the excessive accumulation of
fat that exceeds the body's skeletal and physical standards. The
National Institute of Health (NIH) states that excessive weight
becomes a health hazard when it is 20 percent or more above ideal
body weight.
Obesity becomes a serious health risk when it becomes morbid. In
such cases the patient is susceptible to serious diseases like
chronic heart disease, respiratory diseases or even infertility.
Called co-morbidities, these conditions or diseases may result in
either significant physical disability or even death. Morbid
Obesity is described as having a Body Mass Index of 40 or higher.
According to the National Institutes of Health Consensus Report,
morbid obesity is a serious disease and must be treated as such.
It is a chronic disease, meaning that morbid obesity symptoms
build slowly over an extended period of time.
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Research shows that the recent rise in obesity is due to changed
lifestyles, energy-dense diets and low-levels of physical
activity. However various factors may contribute to obesity which
include environmental factors, heredity, psychological & cultural
influences and many others. Various possible causes of obesity, as
suggested by renowned doctors, are given below:
Heredity
Research shows that heredity influences fatness and the
distribution of fat tissue. Heavy newborns grow into heavy
adolescents only when either parent is overweight or obese. Weight
regulation in the human body depends upon various hormonal and
neural factors which are genetically determined. Any abnormality
in these factors could result in substantial weight gain. Size and
number of fat cells, distribution of body fat, and RMR are also
determined genetically. In 66% to 80% of the cases, obesity is
found to be inherited. Studies have proved that above 250 genes,
markers and chromosomes are linked obesity. Genetic conditions
like the Prader-Willi syndrome may also lead to obesity and linked
diseases.
However, there is no complete consensus on the fact that an
abnormality in genes may lead to obesity. A recent study shows
that while genes may increase vulnerability to obesity, the
presence of other factors, like the environment, is necessary for
obesity to actually occur.
Metabolic Factors
Before we study the metabolic factors that lead to obesity we
need to have a basic understanding of metabolism in the human
body. In short, basal metabolism rate (BMR) is the energy
(measured in calories) used by the body at rest to maintain normal
bodily functions. This continuous activity contributes to 60-70%
of the amount of calories we “burn’ in a day. Increased activity
increases the BMR and the amount of calories burnt. Most obese
people lead an inactive life, thus their energy expenditure is
minimal. Low levels of spontaneous physical activity leads to
vulnerability towards obesity.
Modern lifestyles have also done their share to contribute towards
obesity. Endless hours of working, sitting at the computer and
leisure activities like watching television have reduced energy
expenditure on physical activity. This combined with eating more
calories than needed, have led to the growing problem of obesity.
Endocrinological Causes
Sometimes obesity may be a result of a hormonal imbalance or
glandular problem. However this is a rare occurrence and
contributes to less than 1% of all weight gain in the world.
Diseases like Cushing Syndrome cause substantial weight gain, most
of which is oriented centrally. This kind of obesity may lead to
hypertension and diabetes. In addition some hypothalamic lesions
like tumors, infections or severe trauma could also lead to
obesity. Hypothyroidism may also cause weight gain by reducing the
metabolic rate. Hypogonadism in men and Polycystic Ovarian
Syndrome in women may be associated with mild obesity although the
reasons for weight gain in such cases are yet unclear.
Medication
Certain drugs may contribute to weight gain, such as
corticosteroids, sulfonylureas for diabetes, steroidal
contraceptives and anticonvulsants such as valproate used in
epileptic therapy. Antipsychotics, antidepressants, mood
stabilizers like lithium are medicines that have weight gain as a
side effect.
Psychological Causes
Several research models show that obesity is linked to various
behavioral and emotional processes that may originate due to
genetic or environmental reasons. Though these factors play a
minor role in the development of obesity, they are important in
relation to responses to treatment. For example, many patients
reduce depressive symptoms by eating. These people may gain weight
with one episode of depression and increase it with the next.
Further, concepts of dietary restraints, body image
dissatisfaction and binge eating disorders have been intimately
linked to the increase in obesity today.
Dietary Factors
Various studies conducted attribute an increase in caloric intake
as the major cause of the current obesity epidemic. Changes in
lifestyle, food systems, and increased portion sizes have been
cited as causes for increased caloric intake. Larger portion sizes
have led to a 30% increase in overeating. Eating out frequently
also leads to increased calorie intakes as one meal served in
restaurants and fast food outlets exceeds a person’s caloric needs
for the entire day.
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Health Risks of Obesity
Mortality
Research shows that excessive body weight is linked to overall
health and susceptibility to chronic ailments. It has been proven
that a BMI beyond 20 kg/m2, increases the risk of cardiovascular
death, heart attack and diabetes, even after adjusting for age,
smoking, social class, alcohol consumption and physical activity.
Studies show that non smoking overweight men and women lose 3.1
and 3.3 years of life respectively compared to normal weight non
smokers. These studies have also established that weight
fluctuations increase the risk of death.
Coronary heart disease is the major cause of weight-related death
followed by diabetes mellitus, digestive diseases and cancer.
Evidence suggests that women can reduce mortality rate by 25% in
diabetic, cardiovascular and cancer conditions by achieving a
weight loss of 9 kgs. However if an obese person has already
developed an associated co-morbidity, then planned weight loss of
any amount has been reported to reduce mortality by 20%. It has
also been established the risk of mortality is greater in younger
patients suffering from obesity as compared to older ones.
Morbidity
Obesity is associated with chronic diseases such as heart
disease, Type 2 diabetes, hypertension, stroke, gallbladder
disease, sleep apnea, certain cancers and osteoarthritis. These
chronic ailments tend to worsen with increasing degree of obesity.
Nonalcoholic fatty liver disease which may progress to end-stage
liver disease is now also being recognized as a consequence of
obesity. Obesity may also lead to poor wound healing and poor
antibody response to hepatitis B vaccine.
The multiplicity of problems associated with obesity and benefits
of 10% weight loss can be outlined as –
|
Benefits to the obese of
a 10% weight-loss |
| Mortality |
20-25% fall in total mortality 30-40%
fall in diabetes-related deaths 40-50%
fall in obesity-related cancer deaths |
| Blood Pressure |
Fall of 10mmHg systolic pressure Fall of
20mmHg diastolic pressure |
| Angina |
Reduces symptoms by 90% 33% increase in exercise tolerance
|
| Lipids |
Fall by 10% in total cholesterol Fall by
155% in LDL- cholesterol Fall by 30% in
triglycerides Increase by 8% in
HDL-cholesterol |
| Diabetes |
Reduces risk of developing diabetes by >
50% Fall of 30-50% in fasting glucose Fall by 15% in HbA 1c |
| Rheology |
Decreases blood viscosity by 20-27% Decreases red cell aggregation by 20%
|
Regional Distribution of fat and Health Risk
There are basically two types of obesity; Android or
apple-shape obesity where the excess fat is primarily subcutaneous
abdominal/truncal fat or gynoid or pear-shape obesity where excess
fat is gluteofemoral fat. This fat distribution is determined
genetically and varies among men and women. Android obesity is
more common among males whereas females are more susceptible to
gynoid obesity. While incase of gynoid obesity it is more
difficult to shed weight, the android obesity is linked to chronic
ailments such as glucose intolerance, insulin resistance,
hyperlipidemia and hypertension. Aging is also an important factor
in the development of central obesity. This type of obesity is
also closely associated with the development of metabolic syndrome
(a complex of unified conditions like glucose intolerance, high
blood pressure and alterations in serum lipids).
Psychological Effects
Obesity and dieting are strongly related to an individual’s
psyche. Studies show that many obese people suffer from low self
esteem which frequently manifests itself as anxiety and
depression. A study done on severely obese subjects showed poor
mental well-being. Most of them were also found to be suffering
from anxiety and depression. A further study done on siblings, one
being severely obese and other normal weight, showed that
functional and emotional wellbeing was significantly lower in
severely obese siblings.
Effect of obesity on pregnancy
The risk of obstetric complication is higher in obese women.
Significantly obese women with an IBW of > 135% have a 6.6-fold
higher risk for the development of gestational diabetes, 1.9-fold
risk for pregnancy-induced hypertension, 1.4-fold risk for urinary
tract infections as well as other complications like pre-eclampsia,
thrombophlebitis, post-partum haemorrhage and wound or episiotomy
infections. Factors such as fetal size, especially macrosomia, an
increase in maternal pelvic soft tissue narrowing the birth canal,
late deceleration of the fetal heart rate, intrapartum meconium
staining, prolonged labor, malpresentations and cord incidents
raise the risk of caesarean delivery. This higher prevalence of a
Caesarean delivery occurs with or without antenatal complications.
Fetal weight appears to be a direct function of maternal size,
with more than 50% of obese women having babies who weigh greater
than 3600g. An increased risk of neural tube defects, especially
spina bifida has also been reported in women with BMI greater than
29. Further, the protective effects of dietary folic acid as seen
in leaner women are not seen in women weighing over 70 kg. Studies
have also shown that prenatal deaths were 3 times more common in
obese women than their counterparts.
Obesity and incidence of maternal complications during pregnancy
as summarized as follows –
|
Obesity and Incidence of Maternal Complications
during Pregnancy |
| |
Normal |
Overweight |
Obese |
Massively Obese |
| Number of Subjects |
54
|
48 |
34 |
30 |
| Hypertension (%) |
9.3
|
33.3 a |
54.6 a |
79.3 a |
| Toxemia (%) |
3.7
|
17.8 |
30.3 a |
42.9 a |
| Gestational Diabetes (%) |
1.9
|
12.3 |
39.4 a |
44.8 a |
| Insulin (% patients) |
0
|
2.1 |
12.1 a |
20.7 a |
| Insulin (% diabetics) |
0 |
16.8 |
30.7 a |
46.2 a |
| Urinary infection (%) |
16.7 |
8.7 |
29.0 |
37.5 |
| Preterm Labor (%) |
14.8 |
13.0 |
22.6 |
28.0 |
| Caesarean section (%) |
9.3 |
16.7 |
15.1 |
42.9 a |
|
Hospitalization Outpatients (%) Inpatients (%) |
7.4 9.3 |
33.3 a 33.3 a |
45.5 a 36.4 a |
61.5 a 66.6 a |
| Overall cost |
|
|
|
|
| Normal = BMI of
18-24.9; Overweight = BMI of 25-29.9; Obese = BMI of 30-34.9;
Massively obese = BMI > 35. a = Significantly different
from normal weight group, b = cost assessed as equivalent
outpatient hospitalization. |
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Assessing the Risk Factors
Ideal Weight Table
Find out your approximate ideal weight using the
following table.
|
Healthy weights for Men
- Women. |
|
Height ( In
inches) |
Weight (In Kgs)
|
Middle (Target)( In
Kgs) |
|
58 |
41-54 |
48 |
|
59 |
43-56 |
49 |
|
60 |
44-58 |
51 |
|
61 |
46-60 |
53 |
|
62 |
47-62 |
54 |
|
63 |
49-64 |
56 |
|
64 |
50-66 |
58 |
|
65 |
52-68 |
60 |
|
66 |
53-70 |
62 |
|
67 |
55-72 |
64 |
|
68 |
57-74 |
65 |
|
69 |
59-77 |
68 |
|
70 |
60-79 |
69 |
|
71 |
62-81 |
71 |
|
72 |
64-83 |
73 |
|
73 |
65-86 |
75 |
|
74 |
67-88 |
78 |
|
75 |
69-91 |
80 |
|
76 |
71-93 |
82 |
|
77 |
73-96 |
84 |
|
78 |
74-98 |
86 |
Adapted from The Metropolitan Life Insurance Table. Covers a wide
range of ideal weight according to height.
Note : Refer to a specialist for precise calculation
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BMI
|
BMI |
|
BMI |
Interpretation
|
|
18-24.9 |
Normal |
|
25-29.9 |
Overweight |
|
30-34.9 |
Grade 1 Obesity |
|
35-39.9 |
Grade 2 Obesity |
| 40
and above |
Grade 3 Obesity or Moorbid Obesity |
Grade 1 to Grade 3
Obesity is applicable to all age groups
(Source : World Health Organisations)
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WAIST
|
WAIST |
| |
Increased
Risk to Life |
Substantial Risk
to life
|
|
Men |
> 94 cm (= 34 inches) |
> 102 cm (= 37 inches) |
|
Women |
> 80 cm (= 32 inches) |
> 88 cm (= 35 inches) |
NORMAL WAIST / HIP RATIO
< 1.0 in Males
< 0.8 in Females
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Is Surgery for me?
-
Presence of serious sequelae of morbid obesity
-
30 kg overweight or a BMI> 33 kg/m2 for more than 5 years with at
least one co-morbidity (ASIA PACIFIC GUIDELINES)
-
BMI > 37 with or without co-morbidities
-
Failure of sustained weight loss on supervised dietary and
conservative approaches (OR Multiple unsuccessful attempts at
Weight loss with non-surgical methods)
-
Absence of an endocrine cause
-
Acceptable operative risk
-
Compulsive eaters
-
Educated, compliant patient. Demonstrate willingness to
maintaining dietary guidelines and other follow-up care.
-
Have support from family, spouse, or close friends.
-
Surgery is not recommended for the mentally ill or impaired,
patients known to abuse alcohol or drugs, or those with an eating
disorder such as bulimia.
If the answer to the above is yes, then you should be
seeking the opinion of our Bariatric expert.
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