Obesity

OBESITY

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Definition• A BMI of 25.0 to 29.9 kg per m2 is defined

as overweight; a BMI of 30.0 kg per m2 or more is defined as obesity.

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Historical PerspectivePaleolithic Era > 25,000 years ago

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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…

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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.

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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

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Classification of Overweight and Obesity

• BMIBMI ClassificationClassification <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 above Super Obesity

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What causes Obesity?

• Nutrient and Energy model of obesity: Metabolism Appetite regulation Energy expenditure

GeneticsBehavioral and cultural factors

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Contributors to weight gain

• Socio-economic status• Smoking cessation• Hormonal• Inactivity• Psychosocial/emotions• Medications

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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.

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Energy Energy IntakeIntake

Adipose Adipose tissuetissue

Energy Energy ExpenditureExpenditure

Why is it so hard to lose weight?

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BrainBrain

NPYAGRPgalanin

Orexin-Adynorphin

StimulateStimulateα-MSHCRH/UCNGLP-I

CARTNE5-HT

InibitInibit

Central SignalsCentral Signals

Glucose

CCK, GLP-1,Apo-A-IVVagal afferents

Insulin

Ghrelin

Leptin

Cortisol

Peripheral signalsPeripheral signals Peripheral organsPeripheral organs

+

+

Gastrointestinaltract

Adiposetissue

FoodIntake

Adrenal glands

External factorsEmotionsFood characteristicsLifestyle behaviorsEnvironmental cues

BrainBrain

NPYAGRPgalanin

Orexin-Adynorphin

StimulateStimulateα-MSHCRH/UCNGLP-I

CARTNE5-HT

InibitInibit

Central SignalsCentral Signals

Glucose

CCK, GLP-1,Apo-A-IVVagal afferents

Insulin

Ghrelin

Leptin

Cortisol

Peripheral signalsPeripheral signals Peripheral organsPeripheral organs

+

+

+

+

Gastrointestinaltract

Adiposetissue

FoodIntake

Adrenal glands

External factorsEmotionsFood characteristicsLifestyle behaviorsEnvironmental cues

External factorsEmotionsFood characteristicsLifestyle behaviorsEnvironmental cues

Leptin

• Protein hormone produced by fat cells.• Experiment: Leptin deficient mice: Hyperphasic Insulin resistant Infertile Leptin administration reversed all the symptoms.

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Medical Complications of Obesity

Pulmonary diseaseabnormal functionobstructive sleep apneahypoventilation syndrome

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Nonalcoholic fatty liver diseasesteatosissteatohepatitiscirrhosis

Gall bladder disease

Gynecologic abnormalitiesabnormal mensesinfertilityPCOS

Osteoarthritis

Gout

Phlebitisvenous stasis

Cancerbreast, uterus, cervixcolon, esophagus, pancreaskidney, prostate

Severe pancreatitis

CHD Diabetes Dyslipidemia Hypertension

Cataracts

Stroke

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Consequences of Obesity

Hippocrates recognized that :“sudden death is more common in those who are naturally fat than in lean.”

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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

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Weight Loss Strategies

• Diet therapy • Increased Physical Activity• Pharmacotherapy • Behavioral Therapy• Surgery• Any combination of the above

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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.

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Dieting

• Dieting is highly ineffective - 95% long term failure rate

• Often results in higher weight than before the diet

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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 caloriesAtleast 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.

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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

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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

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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.

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Obesity warning on London buses

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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.

ICD 9 Codes• Obesity: 278• Morbid Obesity: 278.01• Overweight: 278.02

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Questions??