32.1 Introduction to Weight Management

Obesity is a complex health issue involving energy balance, hormones, and genetics. When we consume more energy than we burn, our bodies store the excess as fat. Hormones like leptin and ghrelin play key roles in regulating appetite and metabolism.

Obesity can lead to serious health problems like diabetes, high blood pressure, and sleep apnea. It's diagnosed using BMI and waist measurements. Causes include poor diet, lack of exercise, certain medications, and some medical conditions.

Physiological Mechanisms and Clinical Aspects of Obesity

Energy balance, hormones, and genetics in obesity

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Top images from around the web for Energy balance, hormones, and genetics in obesity

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  Frontiers | Leptin and Obesity: Role and Clinical Implication View original

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• Weight gain occurs when energy intake exceeds energy expenditure, with excess energy stored as fat in adipose tissue
• Hormones regulate appetite and metabolism, including leptin (produced by adipose tissue, signals satiety to the hypothalamus but can lead to leptin resistance), ghrelin (produced by the stomach, stimulates hunger), and insulin (regulates glucose metabolism and fat storage, with insulin resistance potentially increasing fat storage)
• Genetic variations (mutations in leptin receptor gene, melanocortin-4 receptor gene) can predispose individuals to obesity

Clinical signs, symptoms, and comorbidities of obesity

• Increased BMI $weight (kg) / height (m)^2$ indicates overweight (BMI 25-29.9 kg/m^2) or obesity (BMI ≥ 30 kg/m^2)
• Waist circumference > 40 inches (102 cm) in men or > 35 inches (88 cm) in women suggests increased risk of metabolic complications
• Comorbidities associated with obesity include type 2 diabetes mellitus, hypertension, dyslipidemia, obstructive sleep apnea, osteoarthritis, and certain cancers (breast, colon, endometrial)

Causes and diagnosis of obesity

• Sedentary lifestyle, high-calorie nutrient-poor diet, certain medications (antipsychotics, antidepressants, glucocorticoids), and endocrine disorders (hypothyroidism, Cushing's syndrome) can contribute to obesity
• Diagnostic methods include anthropometric measurements (BMI, waist circumference), body composition analysis (bioelectrical impedance, dual-energy X-ray absorptiometry), laboratory tests (lipid profile, fasting blood glucose, thyroid function tests), and sleep studies to assess for obstructive sleep apnea

Non-Drug Approaches to Weight Management

Lifestyle modifications, programs, and surgery for weight management

• Balanced calorie-controlled diet emphasizing fruits, vegetables, whole grains, lean proteins, and healthy fats while reducing processed foods, added sugars, and saturated fats
• Regular physical activity targeting at least 150 minutes of moderate-intensity aerobic activity per week and incorporating resistance training to maintain lean body mass
• Behavioral strategies such as self-monitoring of food intake and physical activity, goal setting, problem-solving skills, and stress management techniques
• Commercial weight loss programs offering structured meal plans, portion control, group support, and accountability
• Bariatric surgery for severe obesity, including restrictive procedures (sleeve gastrectomy), malabsorptive procedures (Roux-en-Y gastric bypass), and combination procedures (biliopancreatic diversion with duodenal switch)