This style of waist band originated in Colombia, one of the planet’s cosmetic surgery hubs. Following surgery, doctors prescribe these bands to use to reduce swelling and make sure the affected skin tightens correctly on patients. However, medical use extended to the general female population as Colombian women realized these bands could also serve to accentuate their natural curves.
The waist band is used to help achieve that “coke bottle” shape. Wearing a waist band gradually moves the organs in the body down in a safe way while also bringing the bottom or “floating” ribs in and closer together resulting in a smaller waist. In addition, waist bands strengthen your posture and lower back muscles, helps to reduce appetite and when worn while working out can help to burn fat with a thermogenic effect on the abdomen.
Think about the waist band as if you're putting braces on your teeth. The braces will straighten your teeth over time and then be removed when your teeth are straight, but in order to maintain them you need wear a retainer at night.
The waist band is very similar. Once you receive your desired results, you won't have to wear your waist band as much — however, it is recommended to wear your waist band daily for shorter periods of time.