Deadgoat, I can understand your thought process on the way a belt is suppose to be used and how that may lead to what your suggesting but it's completely unrelated sorry.
What stu said is the key to what your waist size is. Genetics determine the width and depth of your pelvis/waist.
How you hold your core/abdominal's though is a different story . This is independent on the person's activation, of which some are lazy and will have a 'distended' belly, while others are more in tune and will remain 'tight' throughout the day.
Regardless, even a 'lazy activator' won't have "GH Gut" as you put it. The only distention you will generally see from weak abdominal control is in the lower portion of the stomach, not the entire stomach as with "GH Gut"