Virgo: May I ask how tall you are? 7st sounds like an incredibly low weight, and I assume from your comments about being 7st in a couple of weeks that you're 7st-something now. If your BMI is under 25 then you really shouldn't be doing any kind of vlcd, regardless of whether or not it is nutritionally complete.
Jane: That's a fair comment, and I can certainly see your point. I think that as a short term solution, it's probably not such a terrible idea, as our bodies wouldn't suffer too much from being on an 'insufficient' diet for just a few weeks. As a long term thing though, going into starvation mode (which, theoretically your body would on so few cals, but not enough vits, minerals, etc) could be potentially damaging. On the other hand, in desperation, how many of us have reduced our calories far too low in the past, in an attempt to lose weight, without any thought for whether we're getting complete nutrition? I certainly have, as I knew very little about that kind of thing when I was younger.
Jo x