This document provides an overview of obesity including its definition, epidemiology, etiology, pathophysiology, investigations, management, prevention, and conclusions. Some key points: 1. Obesity is defined as excess body fat that may impair health, and it has become a global epidemic recognized by the WHO in 1997. 2. Worldwide prevalence of obesity more than doubled between 1980-2014, with at least 13% of adults globally being obese. 3. Obesity results from an interplay of genetic and environmental factors like diet, sedentary lifestyle, and certain drugs or medical conditions. 4. Management involves diet, exercise, medications like Orlistat, and sometimes bariatric surgery

1. University of Sulaimani
Faculty of medical sciences
School of Medicine
Department of Family and Community Medicine
Report title:
Obesity
Prepared by:
Aram A. Shah
Ayyub Qadir
Soma Dler
Baxan Swara
Treefa Omar
Supervisor:
Ms Goshan Mohamed Karadaghi

2. Obesity:
Obesity is a medical condition in which excess body fat has accumulated to the extent that
it may have a negative effect on health, leading to reduced life expectancy and/or increased
health problems. 1
For thousands of years obesity was rarely seen.2
It was not until the 20th century that it
became common -- so much so that in 1997 the World Health Organization (WHO) formally
recognized obesity as a global epidemic.3
In June of 2013 the American Medical Association
classified obesity as a disease with much controversy.4
Although during history overweight was sometimes linked with disease and shorter life
span, in general, extra fat was related to wealth, health, and attractiveness. Low weight and
thinness were associated with poverty, malnutrition, and wasting diseases such as
tuberculosis. Scarcity of food throughout most of history meant that most people did not
have the opportunity to become obese.5
Epidemiology:
Overall, about 13% of the world’s adult population (11% of men and 15% of women) were
obese in 2014.The worldwide prevalence of obesity more than doubled between 1980 and
2014. Most of the world's population live in countries where overweight and obesity kill
more people than underweight (this includes all high-income and most middle-income
countries).6
Obesity is a leading preventable cause of death worldwide, with increasing rates in adults
and children. Authorities view it as one of the most serious public health problems of the
21st century.7
Worldwide, at least 2.8 million people die each year as a result of being
overweight or obese.8
While less than 2.7 million deaths have been reported due to AIDS by
the WHO in 2001 and less than 1 million for cancer.9
The United States has the highest obesity rates in the developed world.10
And the United
Kingdom now has the highest rate of obesity in Europe.11
There are two types of obesity:
1. Android obesity: male pattern or abdominal obesity.1
2. Gynoid obesity: female pattern or gluteal obesity.1
Predominant age: obesity can occur at any age. 12
Predominant sex: According to WHO, females are more commonly affected than males.12
 Etiology :
Body weight is ultimately determined by the interaction of genetic, environmental and
psychosocial factors acting through the physiological mediators of energy intake and
expenditure.13
Like many other medical conditions, obesity is the result of an interplay between genetic
and environmental factors.13

3.  Genetic:
Polymorphisms in various genes controlling appetite and metabolism predispose to obesity
when sufficient food energy is present.14
A few rare single gene disorders have been identified which lead to severe childhood obesit.
People with two copies of the FTO gene (fat mass and obesity associated gene) have been
found on average to weigh 3–4 kg more and have a 1.67-fold greater risk of obesity
compared with those without the risk allele.15
The influence genetics have on BMI varies from 6% to 85% depending on the population
examined.16
Obesity is a major feature in several syndromes, such as Prader–Willi syndrome, Bardet–
Biedl syndrome, Cohen syndrome, and MOMO syndrome: Macrosomia (excessive birth
weight), Obesity, Macrocephaly (excessive head size) and Ocular abnormalities.17
 Some reasons for the increasing prevalence of obesity
(obesogenic environment):
 Diet:
Total food energy consumption has been found to be related to obesity.18
Most of this extra food energy is from an increase in carbohydrate consumption rather than
fat consumption.19
The primary sources of these extra carbohydrates are sweetened beverages, which now
account for almost 25 percent of daily food energy in young adults in America, and potato
chips. Consumption of sweetened drinks such as soft drinks, fruit drinks, iced tea, and energy
and vitamin water drinks is believed to be contributing to the rising rates of obesity.20
Increasing energy intake:
Increased portion sizes, increased Snacking and loss of regular meals, increased Energy-
dense food (mainly fat), and increased affluence (Richness). These conditions make the
energy intake more than the expenditure which leads to storing the excess energy as fat in the
body.21
Sedentary lifestyle (decreased energy expenditure):
Currently at least 30% of the world's population gets insufficient exercise.22
Increased car ownership, decreased walking to school/work, increased Automation;
decreased manual labour.23
Decreased sports in schools.24
Increased time spent on computer
games and watching TV.25

4.  Potentially reversible causes of weight gain:
 Endocrine factors leading to obesity:
Hypothyroidism, which is a condition in which the thyroid gland does not produce enough
thyroid hormones which have important role in regulating metabolism and energy
expenditure, is one of the conditions leading to obesity. Cushing’s syndrome is another
condition causing obesity, in this disorder there’ll be excessive production of the hormone
Cortisol by the adrenal gland or exogenous cortisol is taken as medication leading to change
in the fat metabolism. Another condition leading to obesity is growth hormone deficiency,
which is caused by damage to pituitary gland which normally produces growth hormone, or
congenital deficiency of the hormone. Growth hormone has many metabolic functions
including fat metabolism, deficiency of this hormone leads to obesity.26
 Drugs causing obesity:
These include insulin, sulfonylureas, thiazolidinediones, atypical
antipsychotics, antidepressants, steroids,certain anticonvulsants (phenytoin and valproate),
pizotifen, and some forms of hormonal contraception.1
 Infetious agents causing obesity:
An association between viruses and obesity has been found in humans and several different
animal species. The amount that these associations may have contributed to the rising rate of
obesity is yet to be determined. 27
 Pathophysiology:
There are many possible pathophysiological mechanisms involved in the development
and maintenance of obesity. This field of research had been almost unapproached until
the leptin gene was discovered in 1994.28
Leptin and ghrelin are considered to be
complementary in their influence on appetite, with ghrelin produced by the stomach
modulating short-term appetitive control (i.e. to eat when the stomach is empty and to
stop when the stomach is stretched). Leptin is produced by adipose tissue to signal fat
storage reserves in the body, and mediates long-term appetitive controls (i.e. to eat more
when fat storages are low and less when fat storages are high). Although administration of
leptin may be effective in a small subset of obese individuals who are leptin deficient,
most obese individuals are thought to be leptin resistant and have been found to have high
levels of leptin.29
This resistance is thought to explain in part why administration of leptin
has not been shown to be effective in suppressing appetite in most obese people. While
leptin and ghrelin are produced peripherally, they control appetite through their actions on
the central nervous system. In particular, they and other appetite-related hormones act on
the hypothalamus, a region of the brain central to the regulation of food intake and energy
expenditure. 30
 Complications:
Cardiological and Endocrine: Obesity is associated with cardiovascular diseases
including angina and myocardial infarction.31
It increases one's risk of venous
thromboembolism by (2.3) folds.32
Having a BMI greater than 30 doubles one's risk
of congestive heart failure. More than 85% of those with hypertension have a BMI greater

5. than 25. Increased LDL cholesterol (bad cholesterol) and lowered HDL cholesterol (good
cholesterol). One of the strongest links between obesity and disease is that with type 2
diabetes, these two conditions are so strongly linked that researchers in the 1970s started
calling it “diabesity”. 1
Reproductive system: Polycystic ovarian syndrome (PCOS), Infertility, Complications
of pregnancy, Birth defects, Intrauterine fetal death.33
Oncological: A study from the United Kingdom found that approximately 5% of cancer is
due to excess weight.34
These cancers include: breast, ovarian, esophageal, colorectal, liver, pancreatic, gallbladder,
stomach, endometrial, cervical, prostate, kidney, non-Hodgkin's lymphoma, multiple
myeloma. In addition to to Other Dermatological, gastro-intestinal (including
gastroesophageal reflux disease; GERD), neurological, psychiatric, respirological,
rheumatological, urological and nephrological complications.
Figure1:http://www.homeopathicdoctor.co.in/obesity-causes-complications-
prevention/
 Investigation:
Usually these investigations are required to exclude
underlying disease or to determine risk factors.
1. Thyroid function test, to exclude underlying thyroid
disorder.
2. Serum cholesterol and triglyceride for cardiac risk factor.
3. Blood glucose, to exclude diabetes and for cardiac risk factor.
Special tests:
1. Severity of obesity can be quantified using the BMI (Body mass index), which is a
measure of relative size based on the mass and height of an individual.
Table:
BMI
Underweight Below 18.5
Normal 18.5–24.9
Overweight 25–29.9
Obesity: 30.0 and Above
Class1(moderate) 30-34.9
Class2(severe) 35-39.9
Class3(very severe) 40.0 and Above

6. 2. Fat distribution: a waist circumference of > 102 cm in men or > 88 cm in women indicates
that the risk of metabolic and cardiovascular complications of obesity is high.35
 Management:
A. general measures:
The doctor should assess the degree of health risk from BMI and waist circumference, and
Assessment of motivation to lose weight.36
B. diet restriction:
Diet restriction is an important method for obesity management. The diet should be of low
fat, high complex carbohydrates and high fiber quality. Diets to promote weight loss are
generally divided into four categories: low-fat, low-carbohydrate, low-calorie, and very low
calorie. A meta-analysis of six randomized controlled trials found no difference between
three of the main diet types (low calorie, low carbohydrate, and low fat), with a 2–4 kilogram
weight loss in all studies. The composition of the diet should ensure a minimum of 50 g of
protein each day for men and 40 g for women to minimize muscle degradation. Side-effects
are a problem in the early stages and include orthostatic hypotension, headache, diarrhea and
nausea. 36
C. Exercise: improves long term results of weight loss treatment. With use, muscles
consume energy derived from both fat and glycogen. Due to the large size of leg muscles,
walking, running, and cycling are the most effective means of exercise to reduce body fat.
D. medications:
 Orlistat:
Inhibits pancreatic lipase, and thereby decreases the hydrolysis of ingested triglycerides,
reducing dietary fat absorption by ∼30%.37
The drug is not absorbed and adverse side-effects
relate to the effect of the resultant fat malabsorption on the gut, namely: loose stools, oily
spotting, fecal urgency, flatus and the potential for malabsorption of fat-soluble vitamins.38
Orlistat is taken with each of the three main meals of the day and the dose can be adjusted
(60–120 mg) to minimize side-effects.39
 Starch blockers( e.g. Sure Slim):
These new products are extracts of white kidney bean (Phaseolus vulgaris) which inhibit the
pancreatic Alpha-amylase enzyme in small intestine and prevent it from digesting complex
carbohydrates(e.g. starches). These pass undigested into the stool, thus lowering the calorie
intake from meals up to 60% of carb calories. Dosage: 1 capsule thrice daily, just 15 minutes
before meals.40

7.  Sibutramine :
Is a neurotransmitter reuptake inhibitor that reduces the reuptake
of serotonin , norepinephrine, and dopamine, thereby increasing the levels of these
substances in synaptic clefts and helping enhance satiety; the serotonergic action, in
particular, is thought to influence appetite.41
Therefore, it reduces food intake through receptor agonist activity in the central nervous
system. But this drug is a withdrawn medication due to cardiovascular side effects.42
E. Surgery:
‘Bariatric’ surgery to reduce the size of the stomach is by far the most effective long-term
treatment for obesity.43
Bariatric surgery is an operation on the stomach and/or intestines that help morbidly obese
patients lose substantial amounts of weight. While some surgeries restrict the amount of food
that the stomach can hold, others affect the way that food is metabolized; both result in the
outcome of significant weight loss. Various types of bariatric surgery are performed, such as
Laparoscopic sleeve gastrectomy in which a part of the stomach alongside the great
curvature is removed, gastric bypass in which the esophagus will be continuous with the
small intestine bypassing the stomach. The latter is done in case of severe ulceration of
stomach. Another type of surgery is putting a band around the neck of the stomach to
minimize food intake. 44
Figure2:
http://www.mdlingo.com/article/bariatric-surgery-a-means-to-lose-diabetes-along-with-weight

8. Prevention:
Different policy approaches may be needed to achieve improvements in food and physical
activity environments, such as choosing healthier foods (whole grains, fruits and vegetables,
healthy fats and protein sources) and beverages, limiting unhealthy foods (refined grains and
sweets, potatoes, red meat, processed meat) and beverages (sugary drinks), increasing
physical activity, limiting television time, screen time, and other “sit time”, improving sleep,
reducing stress. The latter two have role in hormonal regulation of the body associated with
fat storage and weight.45
Conclusion
Obesity is a medical condition in which excessive fat will be stored in the body and lead to
other health problems and diseases. It has become very common in the last two centuries so
much that it was recognized as a disease. Obesity is a leading cause of mortality globally
causing death of people by millions annually more than AIDS and cancer. It affects both
male and female and it increasingly affects both adults and children. Obesity is caused by
many interacting factors including genetics, diets with high energy intake and low energy
expenditure, endocrine factors such as in Cushing’s syndrome, drugs such as steroids, and
could be caused by some viral infections. The body regulates appetite and satiety by many
mechanisms including the hormone “Leptin” which is released by adipose tissue. It
suppresses appetite and stimulates fat burning by the body for energy. Obesity leads to many
diseases, the most important ones are type 2 Diabetes Mellitus, cancers, and the
cardiovascular diseases including Myocardial Infarction, hypertension, heart failure, and
deep vein thrombosis. Obesity is mostly measured by BMI, which is the body weight (in
kilograms) over squared height (in meters). BMI more than 25 indicates overweight, and
more than 30 indicates obesity. Obesity can be managed by many ways including proper diet,
exercise, medications, and bariatric surgery. It can be prevented by choosing good, healthy
foods and beverages and staying away from bad, unhealthy ones, regular exercise, staying
away from sedentary lifestyle, improving sleep, and reducing stress in your life.

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