Roman soldiers would wear a belt around their waist.
I have not seen much discussion on the purpose of the belt. It would be the base for carrying some items. For example, a dagger, called a puglio, would be on the left side. A money pouch could be carried on the belt, I suppose.
All the comments I’ve read and all the photos of reenactors I have seen describe leather straps hanging from the front of the belt. Since the straps are not woven together and don’t have any more depth than one layer, I cannot imaging they would provide any protection to the abdomen. It seems to me those are decorative items.
If a soldier was wearing chain mail, the belt could be tightened around the mail, thus transferring some of the weight from the shoulders to the hips. That might be good for balancing the load.
The sword, or gladius, would not be hung on the belt. All the discussion I’ve seen says the gladius was worn on the right side for soldiers and carried on a long belt that was looped above the left shoulder.
Parts of the belt, according to The Romans in Britain website:
- Belt – Balteus or cingulum
- Buckle – fibula
- Dangling leather straps – Baltea
- Studs, or pieces of decorative metal on baltea – Bulla, plural bullae
- Pendants at bottom of baltea – pensilia, singular pensillum
- Dagger, hanging vertical off belt on left side – puglio
More discussion of weaponry of Roman Legionnaires.