WTF?

Nike, Adidas and Under Armour all make a full line of performance wear dedicated to the most fit and athletic among us.
But the thing I noticed at the local mall was the number of matching sneakers and jogging suits on the fattest people.
It is as though they consider dashing from Cinnabon, to Sbarro, to Mrs. Field's, and back to Cinnabon as a sporting event.
WTF?
Why do the most unfit people wear active attire?