YbnjhbbnnnmkkkkkkkmmmmmmmObesity- 1.pptx

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1. OBESITY RISK FACTORS Dr S Mukil Asst. Prof - IIM M2

2. Definition of Obesity Obesity is a medical condition characterized by an excessive accumulation of body fat that poses a risk to health. It is typically measured using the Body Mass Index (BMI)**, where: - A BMI of 30 or higher is classified as obese - A BMI of 25–29.9 is considered overweight Obesity increases the risk of various health conditions, including heart disease, diabetes, hypertension, and certain cancers. It results from a combination of genetic, behavioral, and environmental factors, often influenced by poor diet, lack of physical activity, and metabolic disorders.

3. Obesity Measurements Obesity is commonly measured using several methods, with Body Mass Index (BMI) being the most widely used. However, other measurements provide more detailed assessments of body fat distribution and health risks. 1. Body Mass Index (BMI) - BMI = weight (kg) / height (m²) - Categories: - Underweight: BMI < 18.5 - Normal weight: BMI 18.5–24.9 - Overweight: BMI 25–29.9 - Obesity: - Class 1: BMI 30–34.9 - Class 2: BMI 35–39.9 - Class 3 (Severe/Morbid Obesity): BMI ≥ 40

4. 2. Waist Circumference - Measures abdominal fat, a key risk factor for metabolic diseases. - High risk of obesity-related diseases: - Men: >102 cm (40 inches) - Women: >88 cm (35 inches) 3. Waist-to-Hip Ratio (WHR) - WHR = Waist circumference ÷ Hip circumference - Higher ratios indicate greater fat distribution around the abdomen, increasing health risks. - High risk: - Men: WHR > 0.90 - Women: WHR > 0.85

5. 4. Body Fat Percentage - More precise than BMI, measured using: - Skinfold calipers - Bioelectrical impedance analysis (BIA) - Dual-energy X-ray absorptiometry (DXA) - Obesity is defined as: - Men:>25% body fat - Women: >32% body fat 5. Waist-to-Height Ratio (WHtR) - WHtR = Waist circumference ÷ Height - A ratio >0.5 indicates increased health risks.

6. Etiology of Obesity Obesity is a complex condition resulting from multiple factors, including genetic, environmental, behavioral, and metabolic influences 1. Genetic Factors -Family History:Genetic predisposition can influence metabolism, fat storage, and appetite regulation. - Hormonal Imbalances:Leptin resistance (hormone regulating appetite) and other endocrine disorders (e.g., hypothyroidism, Cushing’s syndrome) can contribute to obesity. - Epigenetics:Environmental influences on gene expression may increase obesity risk. 2 . Environmental Factors - Sedentary Lifestyle:Lack of physical activity leads to an energy imbalance and fat accumulation. - Unhealthy Diet:High-calorie, processed, and fast-food consumption contributes to excessive calorie intake. - Food Availability and Marketing:Easy access to high-fat, high-sugar foods influences dietary habits. - Socioeconomic Status: Lower income and education levels may limit access to healthy food and recreational activities.

7. 3. Behavioral Factors - Overeating: Consumption of large portion sizes and frequent snacking contribute to weight gain. - Emotional Eating: Stress, depression, and anxiety can lead to overeating and binge eating. - Lack of Sleep: Sleep deprivation disrupts hormones (ghrelin and leptin) that regulate hunger and satiety. 4. Metabolic and Physiological Factors - Basal Metabolic Rate (BMR): Some individuals have a naturally slower metabolism, making weight management more challenging. - Gut Microbiota: Changes in gut bacteria composition may affect digestion, metabolism, and fat storage. - Age and Hormonal Changes: Aging and menopause can lead to hormonal shifts that promote weight gain. 5. Medications and Medical Conditions - Medications: Certain drugs (e.g., antidepressants, antipsychotics, corticosteroids, and diabetes medications) can promote weight gain. - Medical Conditions:Endocrine disorders such as hypothyroidism, polycystic ovary syndrome (PCOS), and insulin resistance contribute to obesity.

8. 6. Psychological and Social Factors Psychosocial Stress: Chronic stress and trauma can lead to emotional eating and metabolic changes. Cultural and Social Norms: Social behaviors, traditions, and peer influence can impact dietary habits and activity levels. Obesity results from a combination of these factors, making prevention and treatment complex. A multidisciplinary approach, including lifestyle modifications, medical management, and behavioral interventions, is essential for effective obesity management.

9. Risk factors for Obesity Modifiable Unhealthy diet Physical inactivity Emotional and stress related overeating Poor sleep pattern Alcohol and sugary beverages consumption Medication induced weight gain Smoking cessation without lifestyle modification Social and environmental influences Non- Modifiable Genetics Age Sex and hormonal factors Ethnicity and race Medical condition Early life factors

10. Secondary causes of Obesity Secondary Causes of Obesity** Secondary obesity refers to weight gain caused by underlying medical conditions or medications rather than lifestyle factors alone. These conditions often affect metabolism, hormone regulation, or appetite control 1. Endocrine Disorders: These conditions affect hormones that regulate metabolism, appetite, and fat storage 2. Genetic Syndromes: Certain rare genetic disorders can cause severe obesity from childhood 3. Medications That Cause Weight Gain 4. Neurological Disorders 5. Chronic Diseases and Conditions

11. Monogenic forms of Obesity Monogenic obesity is a rare form of obesity caused by mutations in a single gene that directly affects appetite regulation, energy balance, and fat storage. 1. Leptin ( LEP) Deficiency 2. Leptin Receptor (LEPR) Deficiency 3. Pro-opiomelanocortin (POMC) Deficiency 4. Melanocortin-4 Receptor (MC4R) Deficiency 5. Single-Minded 1 (SIM1) Deficiency 6. Brain-Derived Neurotrophic Factor (BDNF) Deficiency

12. Impact of environmental factors Environmental factors play a significant role in the development and progression of obesity by influencing dietary habits, physical activity, stress levels, and overall lifestyle choices. These factors interact with genetic predispositions and behavioral patterns, making obesity a complex, multifactorial condition.

13. 1. Dietary Environment : Availability of Processed and Fast Foods,Portion Sizes and Sugar-Sweetened Beverages (SSBs) 2. Physical Activity and Sedentary Lifestyle: Urbanization and Technology Dependence and Reduced Opportunities for Exercise. 3. Socioeconomic and Cultural Factors: Income, educational status, work and family environment. 4. Psychological and Emotional Factors 5. Environmental Toxins and Endocrine Disruptors

14. Obesity develops progressively over time due to a combination of genetic, environmental, behavioral, and metabolic factors. It typically follows a predictable course, starting from weight gain and potentially leading to severe complications if not managed.

15. Natural history of Obesity 1. Developmental Stages of Obesity a. Prenatal and Early Childhood (Fetal Programming & Childhood Obesity) b. Adolescence and Young Adulthood (Weight Gain Acceleration) c. Early and Middle Adulthood (Weight Maintenance or Progression to Severe Obesity) d. Late Adulthood (Complications and Reduced Quality of Life)

16. Complications of Obesity Metabolic Complications: a. Type 2 Diabetes Mellitus (T2DM) b. Dyslipidemia c. Non-Alcoholic Fatty Liver Disease (NAFLD) Cardiovascular Complications: a. Hypertension b. Coronary Artery Disease c. Stroke

17. Respiratory Complications a. Obstructive Sleep Apnea (OSA) b. Asthma and Chronic Lung Disease Musculoskeletal Complications a. Osteoarthritis (OA) b. Gout Cancer Risk

18. Reproductive and Hormonal Complications a. Polycystic Ovary Syndrome (PCOS) b. Infertility c. Hypogonadism and Hormonal Imbalances Neurological and Psychological Complications a. Cognitive Decline and Alzheimer’s Disease b. Depression and Anxiety

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