I'm 5'9, 185lbs and I have a 32" waist (at my actual waist), 41" chest and do have a slight gut. I'm in decent shape (could be better but I could be worse too) and my doctor considers me very healthy at this point in life. That being said my EDC used to be a cobbled together full size 1911 built on a Colt frame in an IWB holster. Now I've just upgraded to a Para P14.45... and after carrying that around for 2 wks nobody has been the wiser. The gun is carried in the same place all the time and it never gets noticed even with the wider grip and frame.
My wife is 5'4", 130lbs and she also carries a full size 1911... and even on her small frame the gun just about disappears in an IWB holster on her. On hot days though she'll switch out for a smaller gun so she can wear her tank tops and shorts without printing but most of the time she's carrying her 1911.
On the other hand my brother-in-law gave up his full size MP40 for the Shield because he found it easier to conceal the Shield...
I'd say stand in front of your wife and maybe a close friend then put on a variety of guns that YOU might want to carry (one at a time of course) and have them tell you if its obvious or even shows a enough that the casual observer might take a closer look.
This is who we are, what we do.