We had this thread last year around this time didn't we?
My gf used to get these, I think the best thing to do, over the long haul, is increase your program gradually.
It's why a lot of people get them in the spring/early summer. Try to do too much.
It's a separation, but I believe you can ease it by increasing gradually.
But it's a damage. Once you do it, you have to fix it. Like any torn muscle or separation.
It's caused by activity that part of your leg is not used to.
It will repair, but you need to slow down first, then increase gradually.
The posters who talk about shoes and posture are 100% correct. That will help prevent, and differ. And to negate you original post, it has nothing to do with diet really.
The biggest thing is once you have them, don't try to work through them. Go slow, heal, then get to where you want to be.
http://en.wikipedia.org/wiki/Shin_splints