Hey guys, I'm new to metal detecting (just got my first MD) but I'm a long time diabetic. I was diagnosed in 1961 and started on insulin a couple of years after that. It's funny because I was wondering if there were any other diabetics on this forum and I stubmbled across this thread.
First...regarding your feet, consider some custom orthodics (insoles). They may make a world of difference. A podiatrist will do a lot more for you than just cut your toenails.
Now, my best advice from experience is that before you go out and metal detect/exercise you should check your blood sugar with the best invention ever for us diabetics...a glucometer. You don't want your blood sugar to drop while you're out so if it's borderline low beforehand, grab something to eat first. I have personally found that 15 grams of carbohydrates will raise my blood sugar by about 60 points...your mileage may vary and experience will show you how much your metal detecting activities will drop your glucose readings.
In any case, make sure you have something that will raise your blood sugar with you. When I used to golf a lot I would always carry a Snickers in my bag. That was handy until it melted. So now I always carry some jelly candies since they don't melt...and they taste good, too. BTW, I detest those glucose tabs....but they serve their purpose.
Also, if you're insulin dependent, talk to your doc about an insulin pump. It took me years to finally decide to get one and now that I've been wearing one for over ten years I can kick myself in the arse for not getting one sooner. The flexibility that it will give you is pretty much unsurpassed.
So all in all, by golden rules for diabetics are to 1) know your limitations and 2) check your blood sugar.
Happy and healthy hunting from a diabetic lifer!
John