Are clothes sizes getting bigger?

Ok ... I might be losing it, but I'm not certain.  I referee soccer games, I mentioned that before, so I went out before the season to get some new referee shorts and a couple new jerseys.  A new color that everyone seems geeked to wear because it's the new cool thing to do.  I don't understand why the other 4 colors of jerseys weren't good enough, but I digress.  So I head to the website to get my new refereeing gear for the season.  I order all the normal sizes for shirts and shorts.  I get everything and both shirts and shorts are huge.  I mean they almost feel like they're not even the same size that I've been wearing since college.  Is it possible that I'm getting smaller?  Maybe.  I guess I could be losing the muscle I acquired wrestling through college, and I'm replacing that with fat.  However I always thought that muscle weighed more than fat, and I'm not losing any weight.  I guess I'm replacing it with a lot of fat?  Or could sizes of clothes be changing?

I have a full set of NCAA refereeing jerseys that are larges, and they fit me pretty normally.  They might be a little bit big but I'd rather have that than get something that's too small.  I have a full set of high school jerseys that are larges and fit me pretty closely to my NCAA jerseys.  But this new one, I feel like I'm swimming in it, and don't get me started with the medium shorts that are almost down to my knees.  It's a damn good thing they have a fantastic elastic, kindof grippy, waitband.  Everything just looks big on me, but I guess I can't do much about it.  It's not like I can return any of it ... like I said, people are geeked to wear the new color.  So 2 days after I got the jersey in the mail, I was already wearing it to referee high school scrimmages.  So much for returning it.

However this brings me to the thought I had above.  Are sizes of clothes changing?  Could it just be that people in the United States are getting fatter but want to think they are wearing the same size still?  I guess I'll let you know once I go back out and buy a new wardrobe of smaller polo shirts to wear to work.