Although I have only had sporadic periods of up to a month with no grains at all, I just can't do it. I do feel deprived. And, I didn't really notice it helping anything in the way I feel, either, although, that may not have been long enough. My main goal was weight loss. However, I have found a happy medium, which is eating almost no grains during the week, using Ezekial bread when I get the urge, and saving up for a few cheat days where I might have a whole wheat bagel or tortilla. Very occasionally, I eat something with white flour (I started eliminating that a long time ago). Today was one of those days; I had 2 slices of sour dough French toast. Probably the first time in 3-4 months I've had that.
I don't eat any junk food, so I pat myself on the back for that, but that's as far as I can go.