I carry either a full size 1911 or a StarFire .40 (compact) with equal ease and I am not a generously proportioned male. That said the very best is that which you do carry. Better to have and not need, than to need and not have.
Depends on what you like and what you shoot the best. Depends on which caliber as well. I prefer at least a 9mm +P or larger for my self defense caliber. Some choose .380 as a minimum. I also prefer Glocks and find the G19/G23/G32 (9mm/.40s&w/.357sig) compacts or the G29/G30 (10mm/.45acp) sub-compacts to be ideal.
i started out carrying makarov (9 x 18) but i prefered the 1911.
MY 1911 would move around on me a lot.
I found the solution to the problem is to buy a good holster and a good gunbelt.
I bought a comp-tac brand c-tac IWB holster for CCW and it works great.
their site is www.comp-tac.com
The belt I bought is an IWB. It is leather and is about 1/4 inch thick x 1-1/2 wide. This ANCHORS the gun and holster in place. I bought the belt at the location where I went to for my CCW classes.
I now carry my 1911 full sized pistol where ever I go 24/7.