Obesity

Objectives

  • Discuss the epidemiology and etiology of obesity.

  • Explain health risks associated with obesity.

  • Compare classification systems for body size.

  • Discuss nutritional therapy and exercise for obese patients.

  • Differentiate medications and surgical treatments for obesity.

Epidemiology of Obesity

  • 40% of U.S. adults are obese.

  • 1 in 10 children aged 2-5 are obese.

  • Highest obesity rates found in:

    • The South

    • Black and Hispanic populations

    • Lower income and less educated groups

Etiology and Pathophysiology

  • Complexity in processes leading to obesity.

  • Factors include:

    • Excess caloric intake

    • Hyperplasia and hypertrophy of adipocytes

    • Increased lipid storage and fat cell formation.

Classification of Body Weight and Obesity

  • Primary obesity: Excess calories for metabolic needs.

  • Secondary obesity: Due to metabolic issues, anomalies, or medications.

Genetic/Biologic Basis

  • Evidence of genetic susceptibility.

  • Key genes linked to obesity include the FTO gene, affecting appetite and caloric intake.

Physiologic Regulatory Mechanisms

  • Hormones like leptin (suppresses appetite) and ghrelin (increases appetite).

  • Consequences of obesity include insulin resistance, dyslipidemia, hypertension, and increased cancer risk.

Environmental and Psychosocial Factors

  • Poor food access and low physical activity are significant factors.

  • Food served emotional roles and social contexts can contribute to obesity.

Health Risks Associated With Obesity

  • Increased rates of:

    • Type 2 diabetes

    • Cardiovascular disease

    • Respiratory issues like sleep apnea.

  • Psychosocial problems include depression and social isolation.

Classification Systems for Obesity

  • Assessments include Body Mass Index (BMI), waist circumference, and body shape.

  • BMI classifications:

    • Underweight: BMI < 18.5 kg/m²

    • Normal: 18.5-24.9 kg/m²

    • Overweight: 25-29.9 kg/m²

    • Obese: > 30 kg/m²

    • Extremely obese: > 40 kg/m².

Treatments for Obesity

  • Nutritional therapy, exercise, behavior modification, and support groups.

  • Drug therapy options include:

    • Orlistat, Lorcaserin, Bupropion/Naltrexone, Phentermine/Topiramate.

  • Bariatric Surgery:

    • Criteria: BMI ≥ 40, or ≥ 35 with comorbidities.

    • Types include restrictive, malabsorptive, and combinations (like Roux-en-Y).

  • Maestro Rechargeable System: pacemaker-like device regulating appetite.

Metabolic Syndrome

  • Risk factors increase cardiovascular disease, stroke, and diabetes.

  • Diagnosed with 3+ of the following:

    • Waist circumference ≥ 40" (men) or 35" (women)

    • Triglycerides ≥ 150 mg/dL

    • HDL cholesterol < 40 (men) or < 50 (women)

    • BP ≥ 130/85 mm Hg

    • Fasting glucose ≥ 100 mg/dL.

  • Linked to insulin resistance and increased disease prevalence.