How to know if food is GMO

I've seen so many scary articles lately about how a lot of the food we eat has been genetically modified. How are we supposed to know if food has been tampered with in this way?

[b]Buy food labeled  100% [b]organic:-[/b][/b] The US and Canadian governments do not allow manufacturers to label something 100% organic if that food has been genetically modified or been fed genetically modified feed. You may find that organic food is more expensive and different in appearance from conventional products.Also, just because something says "organic" on it does not mean that it does not contain GMs. In fact, it can still contain up to 30% GMs, so be sure the labels say 100% organic.

Thanks, adleylab! I would love to start doing all of my shopping at Trader Joe's, but the nearest one is over two hours away. I'll start looking for the 100% organic labels at my local grocery store.