yes I've practised the eight precepts a few times (usually this was on full moon days), and I agree they can be very useful for strengthening the mind's resolve, clarity and power. But alas, I too am chronically underweight, and I find that I cannot do it too often. Fortunately, I have discovered that skipping anger is much more conducive to spiritual development than skipping dinner. We should keep it in perspective. Between not eating dinner at night, and not yelling at someone who has just pushed us too far, my personal feeling is that giving up the outbust of anger is the more crucial spiritual practice. So, in my experience, if as a householder we find the eight precepts too stressful, and if we become snappy as a result with the people around us, then it would be better to just eat less at dinner time (ie a light easily digestible meal), than to try to fit ourselves into some kind of ideal that is really designed for a more contemplative lifestyle.
Then the Blessed One, picking up a tiny bit of dust with the tip of his fingernail, said to the monk, "There isn't even this much form...feeling...
perception...fabrications...consciousness that is constant, lasting, eternal, not subject to change, that will stay just as it is as long as eternity."