Obesity and Related Factors

Obesity and Related Factors

• Obesity: Excessive adipose tissue in relation to total body mass, assessed using Metropolitan Height and Weight Tables.
• BMI (Body Mass Index): A height-to-weight ratio used to screen for possible weight problems. Calculated by: (weight in lbs * 703) / (height in inches * height in inches).
• BMI Scale: Underweight (<18.5), Normal (18.5-24.9), Overweight (25-29.9), Obese (>30), Severely Obese (>40).
• Education and Income: People with college degrees had lower obesity prevalence, and among men, lower prevalence in lowest and highest income groups compared to middle-income. Black men showed higher prevalence in the highest income group.
• Obesity Risks: Increases risk of a wide range of illnesses (e.g., heart disease, stroke, type 2 diabetes, certain cancers). Also increases risk of serious illness from COVID-19—possibly tripling the risk of hospitalization.
• Obesity Contributing Factors: Consuming more calories than burned through activity.
• Metabolism: The energy (calories) the body burns to maintain itself. Fat tissue is less metabolically active than lean tissue.
• Calories and Fat: 1 gram of fat stores 9.3 calories. 1 lb of fat equals 3,500 calories.
• Fat Cell Growth: During childhood and adolescence, fat cell size and/or number increase. Fat cell number generally increases but does not decrease.
• Hypothalamus Regulation: Monitors leptin and insulin levels, which proportionally reflect body fat, to regulate eating and metabolism.
• Leptin and Insulin: Hormones that influence the hypothalamus to increase or decrease eating behavior and metabolism. High serum insulin (hyperinsulinemia) in obese individuals contributes to hunger sensations. Insulin also regulates blood glucose, glucose-to-fat conversion, and fat storage.
• Neuropeptide Y: A neuropeptide that might trigger increased food intake due to potential mood and stress changes. Could also increase fat deposition.
• Set Point Theory: Humans have a preset body weight range, where the body regulates metabolism and eating patterns to maintain the set point. This is considered an incomplete theory as it fails to account for long-term weight maintenance.
• Stress and Eating: Stress can trigger cravings for certain types of foods (especially sweet and high-fat "comfort foods"). Cortisol can increase cravings for salty and sweet foods. Social support seeking can inadvertently contribute to overeating.
• Psychosocial Factors: "Oral fidgeting" and childhood behaviors can influence eating habits.
• Obesity and Mood: Obese people may be more susceptible to mood disorders (depression) and may experience binge eating, exacerbating the problem.
• Social Network Effects: People with obese spouses or siblings are more likely to be obese.
• Alcohol and Eating: Alcohol consumption leads to a significant increase in calorie intake.
• TV and Metabolism: Watching some TV shows might lower metabolic rate.
• Environmental Cues: Obese people may be more sensitive to food cues like palatable tastes, potentially leading to increased consumption.

Nutritional Components and Free Radicals

• Food Components: Carbohydrates, proteins, fats, vitamins, and minerals.
• Carbohydrates: The body's primary energy source (e.g., grains, potatoes, fruits, milk). Simple carbohydrates are sugars, while complex carbohydrates are starches. (4 calories/gram).
• Proteins: Essential for cell repair and growth, hormone production, and immune function also a source of energy (4 calories/gram).
• Fats: Required for growth, organ cushioning, and cell membrane maintenance (9 calories/gram). Unsaturated fats are important in brain development. Saturated fats and trans fats increase health risks. Triglycerides, omega-3 fatty acids, and trans-fatty acids are important types of fats.
• Vitamins and Minerals: Organic and inorganic substances necessary for metabolism and body function (e.g., calcium for bones).
• Oxidation and Free Radicals: Oxygen loss/free radicals damage cells. Antioxidants counteract these effects.
• Antioxidants: Substances that can donate electrons to free radicals, reducing oxidation and cell damage. (e.g., vitamin E, vitamin C, selenium, beta-carotene, lycopene).
• ORAC: A method to measure antioxidant capacity of food. (Removed from USDA website due to potential for misuse).

Weight Loss, Treatments, and Other Health Concerns

• Weight Loss Attempts: Many adults attempt weight loss, but "bad" dieting strategies are frequently used.
• Yo-yo Dieting: A cycle of weight loss and gain, which may be linked to a lower metabolic rate and increased difficulty in maintaining weight loss. This cycle is associated with decreased life satisfaction, disordered eating behaviors.
• Cognitive-Behavioral Techniques: Strategies to modify eating habits, and control the environment.
• Very-Low-Calorie Diets: Diets with under 800 calories per day can lead to rapid weight losses, but have potential risks including ketosis. Ketosis is the breakdown of fats, when ketones reach certain levels it is possible for the blood to become acidic.
• Physical Activity and Metabolism: Increases metabolism and assists in weight loss. More intense exercise results in more weight loss than dieting alone.
• Blood Pressure: High blood pressure (hypertension) is a concern for many, and high levels of sodium and caffeine can affect blood pressure.

Additional Notes

• Education, income, stress, and social networks significantly affect obesity and health risks.
• Fad dieting strategies often lead to weight cycling, rather that maintaining long-term health.