I've blacked out so many times I've lost count. Pretty sure mine was a combination of lack of food and speed drinking. When I was well and truly drunk then I would allow myself to eat. Not that I remember half of that!
The times I didn't black out were when I was pacing myself and eating. Also I have a low body weight which doesn't help.
I'm only only day 9 but I know what you mean, I'm bargaining with myself still..looking for the loophole!!!