Obesity is a significant health issue due to its association with metabolic complications such as dyslipidaemia, type 2 diabetes, and cardiovascular diseases. While body mass index (BMI) is commonly used to define obesity, recent studies highlight that abdominal obesity, particularly visceral fat accumulation, is a major risk factor for coronary heart disease, type 2 diabetes, and related mortality. Visceral obesity is characterized by a higher risk of metabolic complications, including hyperinsulinaemia, increased apolipoprotein B concentration, and small LDL particles, which increase the risk of coronary heart disease 20-fold. A "hypertriglyceridaemic waist" phenotype, defined by a waist measurement ≥90 cm and triglyceride concentrations ≥2 mmol/l, is a strong predictor of metabolic complications in middle-aged men. Visceral adipose tissue (VAT) is more closely associated with metabolic complications than subcutaneous fat. Anthropometric measurements such as waist circumference are effective in estimating VAT, while advanced imaging techniques like MRI and CT provide more precise assessments. A seven-year study showed that changes in waist circumference better predict changes in VAT than the waist-to-hip ratio. Waist circumference is a simple and effective measure for identifying high-risk abdominally obese individuals. The atherogenic metabolic triad, consisting of hyperinsulinaemia, increased apolipoprotein B, and small LDL particles, is a key marker of visceral obesity. This triad significantly increases the risk of coronary heart disease. Screening tools such as waist circumference and fasting triglyceride levels can help identify high-risk patients. However, sex and ethnic differences affect the relationship between waist measurement and metabolic risk, necessitating different cut-off values for various populations. Obesity should be managed by focusing on high-risk patients with visceral obesity, rather than solely on weight. Moderate weight loss (5-10%) can improve metabolic markers and reduce cardiovascular risk. Physicians should consider waist circumference as a vital sign and integrate it into risk assessment. A multifaceted approach, including balanced nutrition, physical activity, and pharmacotherapy, is essential for managing obesity-related risks. The management of obesity should prioritize metabolic complications over weight alone.Obesity is a significant health issue due to its association with metabolic complications such as dyslipidaemia, type 2 diabetes, and cardiovascular diseases. While body mass index (BMI) is commonly used to define obesity, recent studies highlight that abdominal obesity, particularly visceral fat accumulation, is a major risk factor for coronary heart disease, type 2 diabetes, and related mortality. Visceral obesity is characterized by a higher risk of metabolic complications, including hyperinsulinaemia, increased apolipoprotein B concentration, and small LDL particles, which increase the risk of coronary heart disease 20-fold. A "hypertriglyceridaemic waist" phenotype, defined by a waist measurement ≥90 cm and triglyceride concentrations ≥2 mmol/l, is a strong predictor of metabolic complications in middle-aged men. Visceral adipose tissue (VAT) is more closely associated with metabolic complications than subcutaneous fat. Anthropometric measurements such as waist circumference are effective in estimating VAT, while advanced imaging techniques like MRI and CT provide more precise assessments. A seven-year study showed that changes in waist circumference better predict changes in VAT than the waist-to-hip ratio. Waist circumference is a simple and effective measure for identifying high-risk abdominally obese individuals. The atherogenic metabolic triad, consisting of hyperinsulinaemia, increased apolipoprotein B, and small LDL particles, is a key marker of visceral obesity. This triad significantly increases the risk of coronary heart disease. Screening tools such as waist circumference and fasting triglyceride levels can help identify high-risk patients. However, sex and ethnic differences affect the relationship between waist measurement and metabolic risk, necessitating different cut-off values for various populations. Obesity should be managed by focusing on high-risk patients with visceral obesity, rather than solely on weight. Moderate weight loss (5-10%) can improve metabolic markers and reduce cardiovascular risk. Physicians should consider waist circumference as a vital sign and integrate it into risk assessment. A multifaceted approach, including balanced nutrition, physical activity, and pharmacotherapy, is essential for managing obesity-related risks. The management of obesity should prioritize metabolic complications over weight alone.