The document discusses obesity, defining it as excessive body fat over 35% for women and 25% for men. It outlines the health risks of obesity like heart disease, diabetes, and certain cancers. Factors that contribute to obesity are discussed, like overeating high calorie foods, sedentary lifestyles, genetics, and certain medical conditions. Regional fat distribution is important, with abdominal fat posing more risks than lower body fat. The document provides guidelines for measuring obesity through BMI and outlines treatments like diet, exercise and medication or surgery in severe cases.

1. Obesity: Pathophysiology, And
Risk Assessment
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2. • Obesity:
• Excessive amount of body fat.
– Women with > 35% body fat.
– Men with > 25% body fat.
• Increased risk for health problems.
• Are usually overweight, but can have healthy
Body Mass Index(BMI) and high % fat.
• BMI =weight kilograms / height meters2
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3. • Desirable % Body Fat:
• Men: 8-25%.
• Women 20-35%.
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4. • Regional Distribution:
• The regional distribution of body fat affects
risk factors for the heart disease and type 2
diabetes.
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5. • Body Fat Distribution: Gynoid
• Lower-body obesity--Pear shape.
• Encouraged by estrogen and progesterone.
• Less health risk than upper-body obesity.
• After menopause, upper-body obesity
appears.
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6. • Body Fat Distribution: Android
• Upper-body obesity--apple shape.
• Associated with more heart
disease, Hypertensiion(HTN), Type II Diabetes.
• Abdominal fat is released right into the liver.
• Encouraged by testosterone and excessive
alcohol intake.
• Defined as waist measurement of > 40” for
men and >35” for women.
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7. • Body Fat Distribution:
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8. • Weight Management:
• Balancing energy intake and
energy expenditure is the
basis of weight management
throughout life.
• Dieting and physical exercise.
• Orlistat (Xenical) medication
to treat obesity.
• In severe cases, bariatric
surgery is performed or an
intragastric balloon is placed
to reduce stomach volume.
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9. Pathophysiology
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10. • Role of Brain Neurotransmitters:
• Neurotransmitters govern the body’s response
to starvation and dietary intake.
• Decreases in serotonin and increases in
neuropeptide Y are associated with an
increase in carbohydrate appetite.
• Neuropeptide Y increases during deprivation;
may account for increase in appetite after
dieting.
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11. • Hormonal Regulation of Body Weight:
• Norepinephrine and dopamine—released by
sympathetic nervous system in response to
dietary intake.
• Fasting and semistarvation lead to decreased
levels of these neurotransmitters—more
epinephrine is made and substrate is
mobilized.
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12. • Hormones And Weight:
• 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).
• 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)
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13. 2/13/2012 13

14. • Hunger vs. Satiety:
• Satiety—postprandial state when excess food
is being stored.
• Hunger—postabsorptive state when stores are
being mobilized.
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15. • Hunger vs. Satiety—contd:
• Feedback mechanism with signal from adipose
mass when weight loss occurs—eating is the
natural result.
• Not always identified in the elderly.
• This occurs mostly in young people.
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16. • Causes of Obesity:
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17. • Causes of Excessive Energy Intake:
• Active: large portion sizes, frequent meals and
snacks.
• Passive: excessive intake of energy-dense
foods containing hidden calories.
• Variety of options: the greater the variety of
foods offered, the greater the intake.
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18. • Low Energy Expenditure:
• Sedentary lifestyle.
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19. • Genetics:
• Identical twins have similar weights.
• Genes affect metabolic rate, fuel use, brain
chemistry, body shape.
• The thrifty gene hypothesis postulates that
due to dietary scarcity during human
evolution people are prone to obesity.
• Thrifty metabolism gene allows for more fat
storage to protect against famine.
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20. Genetics:
Obesity tends to run in families.
• If both parents are normal weight – 10%
chance of obesity in offspring.
• If one parent is obese – 40% chance.
• If both parents obese – 80% chance.
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21. • Environmental factors influence weight:
• Overeating learned early in childhood.
• Urging children to eat more, clean their plates.
• Use of food as a reward.
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22. • Medical and psychiatric illness:
• Physical and mental illnesses and the
pharmaceutical substances.
• Hypothyroidism, Cushing’s syndrome, growth
hormone deficiency, and the eating disorders:
Binge eating disorder and Night eating syndrome.
• Insulin, sulfonylureas, thiazolidinediones, atypical
antipsychotics, antidepressants, steroids, certain
anticonvulsants (phenytoin and valproate), and
some hormonal contraception.
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23. • Obesity is a Growing Problem:
• 127 million adults in the U.S. are
overweight, 60 million obese, and 9 million
severely obese.
• 66 percent of U.S. adults are overweight
(BMI≥25).
• 32 percent are obese (BMI≥30).
• 17% of children and adolescents ages 2-19 are
overweight.
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24. • Obesity: A Major Health Issue:
• Obesity is the SECOND preventable cause of
death and disability (smoking is #1).
• Obesity is associated with increased risk of
heart disease, stroke, gallbladder
disease, cancer, osteoarthritis, sleep apnea.
• Obesity-related health problems cost $75
billion annually (2003 data).
• The public pays about $39 billion a year -- or
about $175 per person -- for obesity through
Medicare and Medicaid programs.
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25. • Health Problems Associated with Excess Body
Fat: • Type 2 diabetes
• Surgical risk
• Gallstones
• Lung (pulmonary)
disease
• Cancers
(breast, colon, pa
• Sleep apnea
ncreas, gallbladde
• HTN r)
• CVD
• Infertility
• Bone and joint
• Pregnancy-
disorders
(gout, osteoarthrit difficult delivery
is)
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• Reduced agility 25

26. • Metabolic Syndrome Criteria*:
Three or more of the following abnormalities:
• Waist circumference >102 cm (40 inches) in
men and > 88 cm (35 inches) in women.
• Serum triglycerides of at least 150 mg/dL.
• High density lipoprotein level <40 mg/dL in
men and <50 mg/dl in women.
• Blood pressure >=135/85 mm hg.
• Serum glucose >=110 mg/dl.
–*Adult Treatment Panel (ATP) III Guidelines.
National Cholesterol Education Program, 2001.
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27. • Polycystic Ovary Syndrome (PCOS):
• Endocrine disorder characterized by
hyperandrogenism and insulin resistance.
• Associated with android obesity.
• Affects 5-10% of reproductive age women.
• Erratic menstrual periods, chronic
anovulations resulting in multiple ovarian
cysts; infertility, acne, hirsutism and alopecia.
• Increased risk of heart disease, type 2
diabetes, reproductive cancers.
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28. • Management of PCOS:
• Symptom oriented, as etiology is unclear.
• Individualized diet and exercise plan to
promote weight loss and normalize insulin
levels.
• Medications to alleviate symptoms.
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29. • BMI and Health:
Below 18.5 Underweight
18.5 – 24.9 Normal
25.0 – 29.9 Overweight
Monitor for risk
30.0 and Above Obese
Increased health risk
40.0 and above Severely obese
Major health risk
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30. • REFERENCE:
• Internet: http://medicalppt.blogspot.com
• en.wikipedia.org
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