lower stomach bloating

Hello Marc,

I am 5'10 and 140ish pounds. I am trying to gain strength right now and have noticed that I have made some strides in the right direction recently. However, my lower stomach sticks out significantly further than my upper and middle stomach regions. I do have some lower ab fat, but when I press on my lower stomach it feels very hard(not just fat). I was wondering if this lower ab protrusion could be caused from bad posture when sitting, i.e. hunching over, or maybe eating too much fiber? I know answering this question may be difficult, but I am really just looking for the primary causes of lower stomach bloating/protrusion to see if I am doing any of those things. 

Thank you

Alec