My teenage son has Type 1 Diabetes, so when he's out with friends, etc., he has to carry paraphernalia with him (he doesn't have a pump yet). At first we just used a lunchbag or a fanny pack, but he insisted they were dorky. Then we got him this cross-body messenger bag style accoutrement, and he is very pleased.

It carries all his stuff, but still has a slim side-profile.

I'm also pleased, as this is a well-made bag. The strap is adjustable and should fit just about anyone. It is a little heavier than some of the cheaper and/or more sack-like messenger bags, but it is also more protected and items inside are more protected.  With the slimmer profile, this is not the bag for you if you need to overstuff with your sweater and a bottle of water. But it's very nice as a guy bag.