Weight / Obesity refers to excessive accumulation of body fat that presents a health risk, most commonly defined by a Body Mass Index (BMI) of 30 or higher (overweight is BMI 25–29.9), though BMI has limitations as it doesn’t distinguish fat from muscle or account for fat distribution. Obesity results from a chronic imbalance where calorie intake exceeds expenditure over time, influenced by genetic factors, hormonal imbalances (e.g., insulin resistance, hypothyroidism), certain medications, sedentary lifestyle, poor diet high in processed/calorie-dense foods, sleep disturbances, stress, socioeconomic factors, and sometimes underlying medical conditions like Cushing’s syndrome or polycystic ovary syndrome. It is classified as class 1 (BMI 30–34.9), class 2 (35–39.9), or class 3/severe (≥40), with central (abdominal/visceral) obesity—measured by waist circumference—posing higher risks than peripheral fat distribution. Associated health consequences include increased likelihood of type 2 diabetes, hypertension, cardiovascular disease, stroke, certain cancers (e.g., breast, colon), sleep apnea, osteoarthritis, fatty liver disease, gallbladder issues, infertility, and mental health impacts like depression or low self-esteem.