You can become overweight or obese when you eat more calories than you use. A calorie is a unit of energy in the food you eat. Your body needs this energy to function and to be active. But if you take in more energy than your body uses, you will gain weight. Many factors can play a role in becoming overweight or obese. These factors include:

  • Behaviors, such as eating too many calories or not getting enough physical activity
  • Environment and culture
  • Genes

The Food and Drug Administration has approved the following medicines for long-term treatment of obesity:

  • Sibutramine suppresses your appetite.
  • Orlistat keeps your body from absorbing fat from the food you eat.
  • Contrave
  • Belviq
  • Qsymia

These medicines are for people who:

  • Have a BMI of 30 or higher
  • Have a BMI of 27 or higher and weight-related health problems or health risks

If you take these medicines, you will need to follow a healthy eating and physical activity plan at the same time.