In my opinion, as long as you get the content of three shakes or flapjacks in you somehow each day, it doesn't matter how it gets into you! You could even eat the powder with a spoon right out of the sachet if you wanted to, as long as it's going in you.
This isn't pharmaceutically (??) verified so don't listen to me.. but I don't see the relevance of how much or little water you add - the important stuff is still going into you either way!