Actually more stress will be put upon the ab's and can restrict normal breathing. That's why a lifting belt, super cinched up, should only be used for 2 or 3 max rep's at the most. Lifting belts should not be worn during a complete workout, really no need to. A lot of guy's like wearing them because it can make the waist look smaller and the lats more wider. Vanity reasons only.
If your serious about it than your going to have to get a custom made belt for your body with extra support around the small of the back and even with that you may have to put a folded towel behind there for even more support. Belts are more useful for PL'ers aand Olympic lifters than the regular BB'er.
Lot's of pro's & con's about wearing a belt even during heavy lifts. Take you choice of wearing one or not but in my view there really not needed at all for the support that they are meant to give. Good luck.