So, I don't know that I can comment on the fat aspect...but I've been testing a smart carry for almost a week with a Shield in 9mm, so I can give some thoughts on that. I bought the smart carry as a deep conceal option and possibly a workout bolster. So far it seems to do quite well in these roles. I've been carrying my pistol and a spare mag throughout my activities. I have logged 3 runs with it so far, two 3 mile and a 5 mile, all averaging less than 8:30 minute miles. The smart carry has also been to the gym twice and performed satisfactorily while utilizing all the weight machines there, the only exception being crunches. As I type this I'm wearing the smart carry with 5.11 cargo shorts and a t shirt. The gun in undetectable and fairly comfortable. I prefer to wear it slightly to my left and so that the grip sits directly behind my waste band. I'd say for me it's definitely going to be a good option, but your mileage may vary.