Gym folklore says that wearing a wide leather belt while lifting will support your back, prevent injury, and allow you to lift heavier. And we've all seen the ripped guys strutting around in weight belts at the gym, so they must work, right? Unfortunately science says the exact opposite.
Research done by Stuart McGill, author of Ultimate Back Fitness and Performance, shows that while wearing a belt may temporarily decrease pain and allow for heavier lifts, it can ultimately cause more frequent and more severe injuries. Why? The belts don't teach you how to stabilize your core when you lift and encourage improper form.
Do you need it? No. If you need a weight belt to perform a lift, then you either need to reduce your load or check your form.