well I'm not suggesting anyone do this, but I've taken 10iu with only about 20g protein, that's it, and I was fine (very tired though)... you will break down muscle into glucose to keep blood sugar levels stable enough, I don't think 10iu's is enough to be fatal, worst case scenario I think is loss of conciousness,
but I still wouldn't recommend doing it without anything, and it can only hurt your gains if you consume not enough nutrients while on it, so there is really no point in doing so..
The reason I did it, was it was when there was that massive powerout accross New York/Ontario .. and I couldn't use the blender and was too lazy to mix so much protein, so I just made 1 glass and decided I would take in more if I felt it absolutely nescaserry.