Thanks Erin and not only am I Type 2, but I'm also a she.
You're right, places are changing, sadly places like Yankee Stadium (I can't believe I'm actually cheering for something the Yankees do. Jays fan here.

Anyway...) and the Civic Centre in Ottawa and Copps Coliseum in Hamilton seem to be the exception to the rule. I did send an e-mail to the head of security of the Civic Centre before going to Ottawa in January for Canadians and he was great!! Told me that if I had any problems, to ask for a supervisor and if I was still given a hard time, to show them my glucometer and related accesories. He said if that wasn't proof I actually did need the food I was bringing in, then nothing would and he would deal w/it personally.
Thankfully nothing did, but as I said, that sadly seems to be the exception rather than the rule. Another place that's been fantastic w/me is the SkyDome, now Rogers Centre in Toronto. As long as I've told them I've got water and whatever w/me when they search my bag and why, it's never been a problem.
And just for further clarification... When I said you are there for the day at a skating event/curling bonspiel, a major skating/curling championship spans the time frame of a week or half a week. Once you are in that arena for the day's events,
you are there for the day. Plus, while bringing a cooler is great if you're from the area, if you're not, like I usually am and don't know anyone from the local area at the event, then the cooler option is not an option. As great an option it is.
BTW...Friends of mine attended the last two US National Figure Skating Championships and it didn't matter that people had documentation on them about their respective medical dietary needs. Security was searching everyone's bags and regardless if it was just an odd breath mint, it was tossed. Considering how some people travel hundreds of miles for these events and factor in the cost of the tickets and hotel...Wouldn't you be wondering what kind of options were left to you?