Obesity means accumulation of excess fat on the body. Obesity is considered a chronic (long-term) disease. Obesity is defined as having a body mass index (BMI) of greater than 30. The BMI is a measure of your weight relative to your height.

Weight gain occurs when you eat more calories than your body uses up. Obesity, however, has many causes:

• Genes
• Emotions (depression, hopelessness, anger, boredom)
• Environmental factors
• Sex
• Age
• Pregnancy
• Hypothyroidism
• Cushing syndrome
• Depression
• Certain medications (examples are steroids, antidepressants, birth control pills)
• Prader-Willi syndrome
• Polycystic ovarian syndrome

For most people who are overweight or obese, the safest and most effective way to lose weight is to eat less and exercise more. But also you can add medications that suppress the appetite.