4. Obesity - How Big A Problem…
• 1.7 billion worldwide are
overweight or obese
• The US has the highest
percentage of obese people.
• By 2006, only four states
had a prevalence of obesity
less than 20%. And the
numbers are growing…
4
5. Epidemiology of Obesity
• 31.3% of U.S. males
• 34.7% of U.S. females
• 30% increase in the last 10
years
• Health care costs - >$100
billion/year
• Results in 300,000 preventable
deaths each year in the U.S.
5
6. Obesity and Life Expectancy
• If current rates of obesity
are left unchecked, the
current generation of
American children will be
the first in two centuries to
have a shorter life
expectancy than their
parents.
Olshansky SJ, et al. A Potential Decline in Life Expectancy
in the United States in the 21st Century. NEJM, 352(11):1138-
1145, 2005
6
9. Classification of Overweight
and Obesity
• BMI Classification
<18.5 Underweight
– 18.5-24.9 Normal weight
– 25-29.9 Overweight
– 30-34.9 Obesity Class I
– 35-39.9 Obesity Class II
– 40-49.9 Obesity Class III
– 50 and aboveSuper Obesity
9
11. What causes Obesity?
• Nutrient and Energy model of obesity:
Metabolism
Appetite regulation
Energy expenditure
Genetics
Behavioral and cultural factors
11
12. Contributors to weight gain
• Socio-economic status
• Smoking cessation
• Hormonal
• Inactivity
• Psychosocial/emotions
• Medications
12
13. Nutrient and Energy
Model of Obesity
Obesity results from increased intake of energy or
decreased expenditure of energy, as required by the
first law of thermodynamics.
Energy Energy
Intake Expenditure
Adipose
tissue
13
14. Why is it so hard to lose
weight?
External factors
Brain Emotions
Food characteristics
Central Signals Lifestyle behaviors
Stimulate Inibit Environmental cues
NPY Orexin-A α-MSH CART
AGRP dynorphin CRH/UCN NE
galanin GLP-I 5-HT
Peripheral signals Peripheral organs
Glucose
Gastrointestinal
CCK, GLP-1, tract
− Apo-A-IV
Vagal afferents
Food
Insulin
Intake
+ Ghrelin
Adipose
− Leptin tissue
+ Cortisol Adrenal glands
14
15. Leptin
• Protein hormone produced by fat cells.
• Experiment: Leptin deficient mice:
Hyperphasic
Insulin resistant
Infertile
Leptin administration reversed all the symptoms.
15
16. Medical Complications of Obesity
Pulmonary disease
abnormal function
obstructive sleep apnea
hypoventilation syndrome Stroke
Cataracts
CHD
Nonalcoholic fatty liver disease Diabetes
steatosis Dyslipidemia
steatohepatitis Hypertension
cirrhosis
Severe pancreatitis
Gall bladder disease
Cancer
Gynecologic abnormalities breast, uterus, cervix
abnormal menses colon, esophagus, pancreas
kidney, prostate
infertility
Osteoarthritis
PCOS Phlebitis
venous stasis
Gout
16
19. Treating Obesity
• Measure height and weight (BMI)
• Calculate waist circumference
• Assess comorbidities
• What labs does the patient need?
• Is the patient ready and motivated enough to
loose weight?
• Which diet should you recommend?
• Discuss a physical activity goal
19
20. Weight Loss Strategies
• Diet therapy
• Increased Physical Activity
• Pharmacotherapy
• Behavioral Therapy
• Surgery
• Any combination of the above
20
21. Rate Of Weight Loss
• A realistic goal is from 5% to 15% from
baseline in 6 months of obesity treatment.
• Weight should be lost at the rate of 1-2 lbs
per week, based on the caloric deficit
between 500-1000 Kcal/day.
21
23. Dieting
• Dieting is highly
ineffective - 95% long
term failure rate
• Often results in higher
weight than before
the diet
23
24. Principles Of Dieting
• Women should consume atleast 1200 kcal/day, men 1500
kcal/day.
• Select a diet that has:
>75g/day proteins (15% of total calories)
> 55% total calories from carbs
▪ Fat should contribute 30% or less of total calories
Atleast 3 meals/day.
High fiber (20-30g/day), fruits and vegetables.
Supplement the diet with multivitamis and minerals.
Avoid sugar containing beverages and fat spreads.
24
25. What about all the diets that are out
there?
• Weight Watchers ($13 registration fee, $15
weekly fee)
• Jenny Craig (consultation $200-370, $65
meals/week)
• Tops Club ($20/week)
• Nutrisystem.com ($50/week)
• Atkins Diet
25
26.
27. Medications
A) Serotonin Nor-epinephrine Reuptake Inhibitor:
reduces food intake.
Sibutramine: initial dose 10mg/day, max 20mg/day.
B) Orlistat: Lipase inhibitor. Alters metabolism, dec
absorption of dietary fat. 120mg PO TID
27
28.
29. Surgery
• Roux-en-Y gastric bypass.
• Lap band procedure
Criteria: a) BMI > 40 or >35 with 2 comorbidities.
b) Failure of non surgical methods
c) Presence of 2 or more medical conditions
that would benefit with weight loss.
29
30.
31.
32. Obesity warning on London
buses
The United Kingdom Branch of the International Size Acceptance Association
is encouraging the public to contact World Cancer Research Fund UK to
voice their concerns about this discriminating ad campaign. 32
In 1997, the International Obesity Task Force,10 convened by the World Health Organization (WHO), recommended a standard classification of adult overweight and obesity
Paleolithic: the first period in the development of human technology of the Stone Age
Obesity is a complex, multifactorial condition in which excess body fat may put a person at health risk. According to the U.S. surgeon general, approximately 25 percent of American adults are completely sedentary, and more than 60 percent are not regularly active at the recommended level of 30 minutes per day.5 About 14 percent of young people between 12 and 21 years of age report no recent physical activity. Nearly one half of young persons between these ages are not vigorously active. An estimated 300,000 preventable deaths occur each year in the United States because of unhealthy diet and physical inactivity,6 which are known contributors to obesity.
the past 20 years there has been a dramatic increase in obesity in the United States. In 2006, only four states had a prevalence of obesity less than 20%. Twenty-two states had a prevalence equal or greater than 25%; two of these states (Mississippi and West Virginia) had a prevalence of obesity equal to or greater than 30%.
Presently, there is no precise clinical definition of obesity based on the degree of excess body fat that places an individual at increased health risk. General consensus exists for an indirect measure of body fatness, called the weight-for-height index or body mass index (BMI). The BMI is an easily obtained and reliable measurement for overweight and obesity and is defined as a person's weight (in kilograms) divided by the square of the person's height (in meters) Other Measurements Waist Circumference >35 inches in women or 40 inches in men indicates hazardous fat distribution Waist/Hip Ratios >0.8 indicates hazardous fat distribution
The search for genetic factors involved in obesity should not obscure the truth that the environmental factors probably more important.
In most cases, however, the increasing prevalence of overweight and obesity reflects changes in society and behaviors over the past 20 to 30 years. Lifestyle patterns are influenced by an overabundance of energy-dense food choices and decreased opportunities and motivation for physical activity. Loss of ovarian function results in: Reduced resting metabolic rate Reduced muscle mass Increased fat mass Increased accumulation of abdominal adipose tissue
Excess body fat results from an imbalance of energy intake and energy expenditure (total energy expenditure includes energy expended at rest, in physical activity and for metabolism)
Leptin signals the brain about the quantity of stored fat. Modulates food intake.
Leptin, a hormone secreted by fat cells that was discovered in 1994, was found to not only control food intake, but also to impact other functions that are affected by energy balance which could relate to obesity. High leptin levels trigger growth and readiness for reproduction. Research has shown that overweight individuals have high concentrations of leptin in the blood, indicating that these individuals do not respond to leptin by reducing food intake. Furthermore, endocrine research has found that obese patients respond poorly to leptin, suggesting the presence of leptin resistance.
Waist circumference measurements greater than 40 inches (102 cm) in men and 35 inches (89 cm) in women also indicate an increased risk of obesity-related comorbidities.
The recent increases in the prevalence of overweight and obesity are reflected across all ages, racial and ethnic groups, and education levels in the U.S. In reviewing the following three charts, for instance, one can see that the “average” American categorized under obesity is aged 50-59, Black/non-Hispanic with less than a high school diploma
A 100 kg woman is at the same risk for coronary artery heart disease as a woman who smokes 1 ppd 40% of coronary artery disease is attributed to being overweight
Waist circumference should be measured at a level midway between the lower rib margin and iliac crest with the tape all around the body in horizontal position
No. 1 = Germany (58% of the population) No. 2 = United States of Amerika (57%) No. 3 = Australia (56%)
The Roux-en-Y gastric bypass procedure involves creating a stomach pouch out of a small portion of the stomach and attaching it directly to the small intestine, bypassing a large part of the stomach and duodenum. Not only is the stomach pouch too small to hold large amounts of food, but by skipping the duodenum, fat absorption is substantially reduced.
