Overweight people have a hard time with printing.
Almost all of the concealed carry videos out there feature skinny people.
Not sure what you mean by 'a hard time.'
Not only can pretty much anyone carry without printing, you can probably carry a mid- to full-size pistol with no problem.
The key is in the choice of clothing and method of carry. Case in point, a fanny pack won't print at all, will it?
Lots of people carry concealed using an OWB holster and an outer garment -- untucked shirt, swestshirt, sweater, vest, jacket, etc. -- to cover the holster. Some even opt for shoulder holsters which work well under a suit jacket or windbreaker.
Not everyone dresses the same, so not everyone will find it as easy, or hard, to avoid printing.
But, in the context of appendix holsters, if you have a little more than a muffin top, i question the decision to put a firearm where you might have trouble clearing your belly ....
