CHS 412 Lecture 2

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Transcript CHS 412 Lecture 2

CHS 412 Lecture 2
Health Education to prevent and control Obesity
and its danger
Dr. Ebtisam Fetohy
Objectives of the lecture
At the lecture the students will be able to:
1-Define Obesity
2-List different methods for measurements of obesity
and overweight
3-Classify obesity
4-Identify advantages and disadvantages of BMI to
assess health risks
5-List Causes of obesity
6-List diseases associated with obesity
Obesity as a public health problem
The rapid rise in the prevalence of obesity in
both rich and poor countries in recent years has
been described as an epidemic.
• At the global level, excess body weight is the
sixth most important risk factor for ill health.
• Many adverse health outcomes are strongly
How is obesity measured?
It is defined as the excessive accumulation of body fat.
-There are a number of ways to measure body fat:
Measurements that are simple, cheap and
appropriate for routine use include:
• Waist circumference
• Hip circumference
• Waist-to-hip circumference ratio
• Indices derived from weight and height, e.g. body
mass index
• skin fold thickness using calipers (e.g. triceps,
How is obesity measured?
• Measurements of body fat that are
expensive and require special equipment
and highly trained personnel include:
Underwater weighing
Bioelectrical impedance ‫المعاوقة‬
Classification of obesity (1) –
‘apples’ and ‘pears’:
1. The apple shape: also called “android”,
“abdominal” or “central” obesity
• People with high waist-to-hip ratios are "apples",
• Their body fat is distributed mainly on the upper
trunk, the chest and abdomen giving the typical
‘apple shape’
• Individuals are mostly male
• A waist-to-hip ratio >1.0 for men and >0.8 for
women indicates an increased risk of cardiovascular disease and diabetes mellitus
Classification of obesity (1) –
‘apples’ and ‘pears’:
2. The pear shape: also called “gynaeoid” or “peripheral”
• People with lower waist to hip ratios are "pears“ –
• Their body fat is distributed mainly on the lower trunk,
the hips and thighs giving the typical ‘pear shape’.
• Individuals are mostly female.
• Associated health risks are minimal if any. Obesity can be
classified into two groups on the basis of body fat
distribution and the waist-to-hip circumference ratio.
-This simple classification is easily understood by the public
and also predicts the risk of obesity-related health
Classification of obesity (2) –
body mass index (BMI):
• Classification of obesity (2) – body mass index
(BMI) BMI = weight in kilograms - kg/m2square of height in meters
Over weight definition 1
Note: Although overweight is identified by a BMI
of ≥ 25.0 kg/m2, the risks of obesity-associated
diseases, such as:
• Diabetes,
• Hypertension and
• Dyslipidaemia, increase from a BMI of about
21.0 kg/m2.
NIH: A weight and height chart is a useful
clinical tool to determine a person’s BMI
Advantages of using BMI to classify obesity
• It is low-cost and
• Easy to use for health professionals for assessing
individuals, it is commonly used to determine desirable
body weights and
• It allows people to compare their own weight status to that
of the general population
• It correlates well with the amount of body fat as measured
by more complex techniques
• It predicts dangers associated with obesity; as BMI
increases the risk for diseases increases
• It is a useful screening tool to use at the population level
• Because it is universally accepted, BMI reference data is
available for many different populations
Disadvantages of BMI
BMI: Which of these men is at risk of ill health and why? (a)
(b) These men have the same height, weight and BMI, but
have different percent body fat BMI calculated as follows:
BMI = 28.4 kg/ m2. Although BMI is equally high in both
men, it is not known:
(a) It is due to lean body mass or
(b) It is due to body fat.
-This shows that, used alone, a high BMI is not diagnostic of
obesity. BMI also varies with age and sex in those <18
years. These are some of the disadvantages of using BMI
to assess health risks.
Put “true” or “false”:
• Obesity is the excessive accumulation of body fat
• Body mass index (BMI) is the most universally
accepted index of obesity
• A woman with a BMI of 46.0 is overweight
• To calculate the BMI of an individual, we need
the weight, height and body fat distribution
• A man with weight 76 kg and height 1.55 m is
Question 2:
A 25 year old male athlete weighs 87.3kg and
has a height of 1.75m:
A. Calculate his BMI How would you classify his
B. Is the classification of obesity based on BMI
reliable for this man and, if not, why?
The global burden of obesity
The USA has the highest obesity rate in the world.
IN American adults, 50m are obese (BMI >30.0) and
6m have class III obesity (BMI >40.0).
Obesity in adolescents has increased from 5% in 1966 1970
Obesity in adults on the increase - worldwide
• Dramatic increases in obesity in recent years is
not confined to the USA.
• Obesity in children living in poorer
countries: Obesity in children living in poorer
countries Africa & Middle East: 4 year olds
• Latin America and Caribbean: 4-10 year olds
• Prevalence of overweight in 10-year old
The burden of obesity – costly, deadly…:
• The financial burden of obesity: WHO data show
that obesity accounts for 5-10% of the total health
care budget in several developed countries
• This is probably a low estimate as not all of the cost
of management of obesity and its related problems
can be calculated
• In 2000, the U.S. spent $117 billion on obesity (9%
of the national total health budget)
The burden of obesity – costly, deadly…:
• The morbidity and mortality burden of obesity: Overall,
about 2.5 millions deaths are attributed to
overweight/obesity worldwide In the UK, about 30,000
deaths are attributable to obesity.
• Ten times this figure occurs in the US where obesity is
the second greatest preventable cause of death following
• Nearly 70% of cases of cardiovascular disease are
associated with obesity
• Obesity predisposes to an overall reduction of quality of
life and premature death from diet related, chronic noncommunicable
People who are obese or overweight also have a
lower life expectancy
• A 40-year-old nonsmoking male who is overweight will
lose 3.1 years of life expectancy; one who is obese will lose
5.8 years.
• A 40-year-old overweight nonsmoking female will lose 3.3
years of life expectancy; one who is obese will lose 7.1
Questions 3:
Write “T” or “F”:
1. Obesity is a worldwide public health problem
2. Obesity is not a major public health problem in
developing nations
3. The highest rate of obesity is found in the U.S.A
4. Obesity related problems account for less than 5%
of healthcare budget in developed countries
5. Obesity leads to premature death from diet related
chronic communicable diseases.
Calories in and calories out – the imbalance
The energy value of food can be expressed in calories.
Obesity occurs when a person consumes more calories
than his/her body needs.
Excess calories are stored as fat and lead to weight
increase. For e.g., consuming 3,500 calories more than
the body needs results in a gain of 0.45kg of fat.
The factors which affect the balance between calories in
and calories out differ from one person to another.
Obesity is believed to result from a complex interplay of
the following factors:
Genetic factors
Socio-economic (lifestyle and diet)
Cultural factors
Psychological and medical factors
Genetic factors:
• We know that obesity tends to run in families,
suggesting a genetic cause.
• Although, families also share diet and lifestyle, both of
which contribute to obesity, research has shown that
genetic factors account for as much 80% of the link
between heredity and obesity.
• Studies in adoptees ‫ المتبنون‬and twins strongly support
this link: Adults who were adopted as children have
weights closer to their biological parents than to their
adoptive parents
• Monozygotic (identical) twins show a much stronger
correlation in body weight than dizygotic (nonidentical) twins.
Socio-economic factors and lifestyle
Diet Apart from our genes, environmental factors
also contribute to the recent surge ‫ زيادة مفاجئة‬in
obesity. The following changes in diets across the
world play a major role:
• Increase in consumption of energy dense foods –
containing animal fats
• Decrease consumption of complex carbohydrates
and fibre - coarse grains, fruits
• Increase intake of salt and alcohol
Socio-economic factors and lifestyle
In recent years, societies of the western world have enjoyed
an over abundance of food –
• So people feast ‫ تمتع‬on larger portions at low prices.
• As this “affluence” ‫ اليسر‬creeps into the urban centres of
the developing world, we are beginning to see a rise in
• The growth of the fast food industry has made an
abundance of high fat, inexpensive meals widely
available, resulting in a shift in stable ‫ المستقرة‬foods from
low quality staples (corn) to high quality refined staples
Cultural factors (1):
• The cultural practice of placing young women in ‘fattening
rooms’ for months before marriage or after childbirth. In
fattening ‫ تسمين‬rooms, the daily routine was to:
1. Sleep ,
2. Eat and
3. Grow fat. The women spent their time resting like
beached whales and gorging ‫ التهام‬on a high-fat, highcalorie diets. This practice has greatly reduced in recent
years in south-eastern parts of Nigeria.
• In certain cultures of the world ‘big is beautiful’. Obesity
was a sign of wealth and well-being in the past and still is
in many parts of Africa.
Cultural factors(2):
In contrast to many Western cultures where thin is, in
many culture-conscious people in these parts hailed
‫رحبت‬, a woman's rotundity ‫ تكور‬as a sign of good health,
prosperity ‫ ازدهار‬and allure ‫اغراء‬.
The Japanese sumo wrestlers ‫ مصارعون‬are well known
obese individuals. They achieve their big size from:
1. An elaborate ‫ متقن‬rice- based diet,
2. Fat-rich stew ‫ حساء‬and
3. Lots
Psychological and medical factors:/1
1. Psychological factors are known to influence
eating habits. Many people eat in response to
negative emotions, such as anger, sadness or
boredom .
2. Metabolic and organic factors including drug
therapies have been associated with obesity as
metabolic rate slows down, the tendency to gain
weight increases. Slow metabolic rate is found
with reduced physical activity, advancing age, and
in females compared to males
Psychological and medical factors:/ 2
3. Certain medical conditions are associated with
obesity: depression, hypothyroidism, pituitary
tumors, cerebral diseases including infections,
hydrocephalus, as well as certain chromosomal
anomalies – Down syndrome.
4. Drugs that can cause weight gain include:
Question 5:
Which of the following factors will increase the
risk of obesity in an individual? Write “T” or
A. Physical inactivity
B. Consumption of fast foods
C. Psychological depression
D. Normal sized parents
E. Hyperthyroidism
Question 6:
• Several factors play a role in the pathogenesis of
obesity. What risk factors match the following
pictures?: a)? c)? b)?.
Obesity is a disease.
Associations with obesity are protean ‫متقلبة‬.
Medical associations of obesity:
Hypertension and
Type II diabetes
Coronary artery disease, and
Cancers and
Reproductive abnormalities
Psychological complications including eating disorders,
Effects of obesity
Obesity - a known risk factor for several lifethreatening medical conditions
(1) Diabetes Mellitus (DM) :
• The relation between obesity and type II diabetes
(non-insulin dependent diabetes) has been
established since the 1970s excess. Fat deposits in
obesity is associated with:
1. Insulin resistance,
2. Glucose intolerance and
3. Premature type II diabetes.
(1) Diabetes Mellitus (DM):/2
• 90% of patients with type II diabetes have BMI
higher than 23kg/m2
• The risk of type II DM is greatly increased where
there is:
A.A history of early weight gain (childhood
B.Android obesity (The apple shape),
C.Positive family history of DM, and
D.Maternal history of gestational DM.
Obesity - a known risk factor for several lifethreatening medical conditions
(2) Coronary artery disease and stroke:
• The effect of obesity on cardiac function is thought
to be due to a combination of:
1. Hypertension,
2. Diabetes mellitus,
3. Dyslipidaemia and
4. Increased fat mass
• The risk increases as BMI values exceed 21.0
kg/m2. Studies show that heart failure in 14%
women and 11% men is due to obesity
The risk for cancers is more among the obese
than the non-obese population estimates
indicate that overweight and inactivity account
for a quarter to a third of cancers of the:
Kidney and
(4)Psychological features of obesity:
• In US women obesity increases the risk of being
diagnosed with:
Major depression by 37%
Low self esteem,
Anxiety, ‫قلق‬
Depression and
Obsessive ‫ االستحواذي‬behaviors are common among
obese individuals especially women
Obesity and depression are linked closely with two
eating disorders:
A. Night eating syndrome and
B. Binge ‫ افراط‬eating disorder (including bulimia ‫النهم‬
 These need early recognition and early psychotherapy
Other effects of obesity (2):
1. Obesity has serious deleterious effects on quality of
There is the social stigma associated with obesity, 20% of obese
people are less likely to marry than their thinner counterparts
The annual household income of obese people is nearly $7,000 less
than that of thinner people
An obese person is 10% more likely to live a life of poverty
5. With obesity there is:
Restricted activity,
Exercise intolerance,
Low self esteem, and
Question 7
Which of the following are recognized
associations of obesity. Write “T” or “F”:
a) Hypertension
b) Type 1 diabetes
c) Osteoarthritis
d) Ovarian cancers
e) Coronary
What is childhood obesity ?/1
Defining childhood obesity : Obesity in childhood
has reached epidemic levels.
• In the US, it is the most common nutritional
disorder in children.
• Developing countries are also affected as the
prevalence rises among children of urban dwellers
who emulate ‫ يحاكي‬the ‘affluent western lifestyle’
What is childhood obesity ?/2
As in adults, the WHO uses the body mass index (BMI) as
the standard definition of obesity in children.
 BMI is calculated with the same formula for children
and adults, but the results are interpreted differently:
 BMI for children, also referred to as BMI-for-age, is
gender and age specific
 BMI changes dramatically with age in children as body
fat changes with growth, and between girls and boys
with maturity
 BMI-for-age, gender specific growth charts used for
children and teens 2 – 20 years of age.
Defining childhood obesity:
BMI-for-Age is used for children and teens because
of their rate of growth and development.
• It is a useful tool because:
A. BMI-for-age in children and adolescents compares
well to laboratory measures of body fat
B. BMI-for-age can be used to track ‫ تعقيب‬body size
throughout life
 In children, obesity is defined as a BMI greater than
the 95th percentile for age
o while overweight is a BMI greater than the 85th
percentile for age till the 95th percentile for age
Risk factors for childhood obesity/1:
Obesity in one or both parents
Infants of diabetic mothers
Children from single parent families
Families with fewer children and
Higher birth weight
Risk factors for childhood obesity/2:
6. Rapid growth during infancy are associated
with an increased prevalence of obesity
7. Formula feeding during infancy
(Breast feeding in women who didn't smoke
during pregnancy [but not in women who
smoked during pregnancy] was significantly
associated with a reduced risk of obesity)
Risk factors for childhood obesity
• Sedentary lifestyle – increase TV viewing,
computer games, car rides, including a reduction in
number of mandatory physical education classes in
schools especially in the US
• Increase consumption of sugar sweetened drinks,
soda, snacks, energy dense fast food in large
The relationship between childhood and adult
• Born in the 60’s with a birth weight of 2.7kg (normal
weight), she quickly became plump in infancy. Neither
parent was overweight (father 72.6kg and1.72m; mother
50.8kg and 1.52m) From the age of 7, she was significantly
heavier than her peers. In her early teens, she “weighed
88.9kg” and was advised by her pediatrician to join a
slimming club. The weight gain persisted till adulthood.
She is currently on nine different medications for obesity
related problems
• bridesmaid ‫ وصف‬at wedding-Married at age 40 weight 178 kg, Height - 1.65m, BMI = 66 kg/m2
The relationship between childhood and adult
Now that you have read
this story, list 5
problems that may
occur in this woman.
Mrs. S. actually
type II diabetes
5. recurrent cellulitis Other
possible problems include :
6. osteoarthritis
7. stroke
8. metabolic syndrome
9. coronary heart disease
10.menstrual disorders
11.psychological disorders
12.cancers – ovarian, endometrial,
breast, cervical, prostate
Question 8:
• The following are statements about childhood
obesity. Write “T” or “F”.:
a) Obesity is not a problem in children
b) BMI-for-age is used for children and teens because of
their rate of growth and development
c) The use of BMI to define obesity doesn’t depend on
d) BMI-for-age in children and adolescents compares well
to laboratory measures of body fat
e) The longer a child remains obese beyond age 3 years,
the more likely that the obesity will persist into
Management of obesity/1:
Effective management of obesity requires long-term
strategies and an integrated, multi-disciplinary approach
that includes:
1. Community-based support for behavioral modification
including: diet and exercise.
2. Research over the last decade indicates that a 5-10%
reduction in body weight is sufficient to significantly
improve medical conditions associated with obesity,
such as:
 Hypertension,
 Diabetes mellitus, and
 Elevated cholesterol levels.
Management of obesity/2:
Currently there is lack of evidence of effective
programmes for integrated management of
obesity. But the following management options
for the management of obesity exist:
A. Dietary modification
B. Behavioral modification
C. Physical activity
D. Pharmacotherapy
E. Surgery
Management of obesity/3:
As always, “prevention is better than cure”.
1. Recently the UK government has set a target
to halt ‫يوقف‬
the rise in obesity in children
aged ≤11 by 2020.
2. Strategies for the prevention of childhood and
adult obesity may need to address factors
during or before infancy that are related to
infant growth.
Management options (1):
Dietary modification the most common and
conservative treatment for obesity utilizes:
A nutritionally balanced diet,
Low calorie diet,
Diet must include more fruits and vegetables,
nuts, whole grains and exclude fatty and sugary
consisting of 1,200 to 1,500 calories per day,
The calories usually in the following proportions:
60 % carbohydrate,
30 % fat, and
10 % protein.
Individuals must be carefully screened and medically
supervised while on the diet (the degree of weight loss
being dependent on individuals ability to adhere to
dietary recommendations)
 Studies have shown that meal replacements ‫ بدائل‬are
often more effective than very low calories diets,
resulting in an increase in the amount of initial weight
loss and enabling dieters to maintain their weight loss
Management options (2) Pharmacotherapy:
• It is recommended that anti-obesity drugs be
used only in:
1. Individuals aged 18-75yrs with a BMI of
30kg/m2 or more.
2. Individuals with a BMI of ≥27kg/m2 with
existing risk factors such as diabetes, cardiac
disease, obstructive sleep apnea or hypertension.
3. Individuals with a BMI of >30kg/m2, in whom
at least 3 months of managed care (supervised
diet, exercise, and behavior modification) fails to
lead to significant reduction in weight.
Two drugs have been licensed for use in the
treatment of obesity:
• Orlistat - prevents fat digestion and absorption
by binding to gastrointestinal lipases; useful for
those with a high intake of fat.
• Sibutramine - reduces appetite and increases
thermogenesis; recommended for those who
cannot control their appetite.
 These drugs should not be used as sole therapy
for obesity.
Their use requires strict regular monitoring and
must be discontinued if
A. weight loss is <5% after 12 weeks of use or
B. weight gain recurs while on the drugs
• Anti-obesity drug treatment should not be used
beyond a year and
• Never beyond two years as few studies have
examined the consequences of their long-term
• Gradual reversal of weight loss is known to
occur on stopping pharmacotherapy
Question 9:
Mark the following statements as either True or False:
A. Obesity management requires an integrated multidisciplinary approach
B. Regular exercise is the single best predictor for achieving
long-term weight control
C. Diet must exclude more fruit and vegetables, nuts, whole
grains and include fatty and sugary foods
D. The criteria for use of pharmacotherapy is a BMI > 20
kg/m2 with persistent co-morbidity
E. A 5-10% reduction in body weight is sufficient to
significantly improve medical conditions associated with
What Have I Learnt about Obesity? (1):
• Obesity is the excessive accumulation of body fat, best
defined by the Body Mass Index (or Quetelet's Index).
• BMI is the universal and convenient measure of obesity.
• It is calculated as weight divided by height squared (kg/m2).
• The BMI-for-age is used to assess obesity in children.
• In adults (age 18years and > 30 kg/m2,), obesity is defined
by a BMI, while of overweight by a BMI between 25 and
29.9 kg/m2.
• A child with a BMI-for-age >95th percentile is obese while
one with a BMI-for-age >85th percentile is overweight.
• The longer a child remains obese beyond age 3 years, the
more likely that the obesity will persist into adulthood. 30%
of obese children are also obese as adults. 70% obese
adolescents end up as obese adults.
• Obesity is believed to result from a complex interplay of
several factors; genetic, environmental (lifestyle and
dietary), cultural, socio-economic, psychological and
medical conditions.
• Obesity is a known risk factor for several life-threatening,
chronic medical and metabolic conditions: hypertension,
coronary artery disease, stroke, type II diabetes, cancers.
• A 5 - 10% reduction in body weight has been shown to
significantly improve medical conditions associated with
What Have I Learnt about Obesity? (2):
• Obesity has reached epidemic proportions in several
developed countries of the world and is also creeping up in
urban cities of the underdeveloped world.
• Globally, there are more than 1.1 billion overweight adults,
and at least 312 million of them are clinically obese.
• 10% of all children worldwide are either overweight or
obese, while 17.6 million children under the <5y are
estimated to be overweight.
• Rapid urbanization and economic development have led to
changing lifestyles and diets across the world which
promote excessive weight gain.
• An increasing incidence of obesity is also being seen in the
poor, developing countries of the world
• Increase body weight is now the sixth most important risk
factor contributing to the overall burden of disease