i have mine at 12, 4, 8 - i make sure i have at least 1.5 ltr in the morning, as i'm not hungry then.
although weekends are different... i tend to have an early shake 8ish, and then lunch at 5 ish, and final at 9 ish... depends if i've been out all day.
you'll be lacking vit\s minerals if you don't have all of them - i was told the calories aren't so relevant, its the nutrition thats important.
good luck,
caren.