Hiya, it's not really recommended to miss a shake because all three of them make up the barest minimum calorie intake that a person should have, and thats why we lose the weight so quickly, so to miss one regularly would be to put your body into starvation. I know the men's LT packs are only allowed two a day but they are more fortified and the XY's need to have more calories than we do.
I've missed shakes in the past three weeks I've been on it, one day because I was feeling unwell and any other occassions if I've cheated and had something to eat, in which case I've already had the calories allowed from my meal replacement shake, but then I've deprived myself of the essential nutrients I need everyday.
Have you tried making them up as a mousse if you can't stand the water? You might find them easier to eat that way (If you just think of it as angel delight) I think the strawberry one is the nicest made up like that so maybe give it a go.
What week are you on? Because you might also be able to try the 'flapjacks' (Or as I call them, dehydrated s***)
xxxxx