Obesity - What is it?
What Is Obesity?
Obesity is a complex, chronic, progressive, and relapsing disease characterized by an excess amount of body fat that negatively affects health.
Obesity has become a major global public health challenge, affecting people across all regions, ages, and demographic groups. According to the Centers for Disease Control and Prevention (CDC), its prevalence continues to increase worldwide.
Obesity develops through a complex interaction of genetic, biological, hormonal, metabolic, environmental, and social factors. It is not simply the result of individual behavior or willpower. People living with obesity may experience changes in appetite regulation, including increased hunger and reduced feelings of fullness.
Obesity is commonly diagnosed using body mass index (BMI), with a BMI of 30 kg/m2 or higher indicating obesity (see “Are You a Candidate?” for more information).
People living with obesity have a higher risk of developing serious health conditions and may experience a reduced life expectancy compared with people in lower BMI categories.
Obesity does not necessarily indicate adequate or healthy nutrition. Exposure to energy-dense, nutrient-poor foods-often more affordable and widely available-can contribute to malnutrition alongside obesity, beginning as early as prenatal development.
Obesity is a treatable medical condition, and management should always focus on improving health, quality of life, and long-term disease control.
Causes of Obesity
Obesity results from a combination of factors, including:
- Genetic susceptibility
- Biological and hormonal regulation
- Environmental and socioeconomic influences
- Psychological and behavioral factors
Risk Factors
- Advancing age
- Family history of obesity
- Sedentary lifestyle and low physical activity
- Dietary patterns influenced by environment and access
- Pregnancy
- Inadequate sleep
- Certain medical conditions (e.g., hypothyroidism, depression)
- Medications (e.g., corticosteroids, antidepressants, antiepileptics, some antidiabetic and antiretroviral treatments)
