I've been losing weight, and it was just vanity that made me order a large instead of XL.  It fits a bit snugly.  I am still losing weight, so I'll grow into it.
What I wanted this for was sun protection in the Mojave desert.  I hate putting sunscreen on any part of my body, but an ordinary T-shirt leaves too much exposed.  This fabric is very lightweight and breathes nicely, so it does not add to body heat when it is 100 degrees outside.