The other way around too - if your metabolism adjusts to the quantities you are eating, then how come we put on so much weight when we overeat???
Yes, the metabolism will go up, but just like it goes down and stops, it'll go up and stop....to your body setpoint. It stays there for a while, but you can push it up further and further. Some people's just stop and they can appear to eat without putting on weight. It's in the genetic hormones which control hunger, cravings, body setpoint etc.
So, if you are 10st and you require 2000kcals, then eat more and just the fact that you are eating will raise your metabolism a little. That doesn't mean the more times you eat the more you burn BTW...just how much you eat.
But you eat faster than the metabolism raises (especially in ladies) and hey presto, you are up to 10st 7lbs.
Now your body needs more kcals to maintain. Your metabolism goes up, but we eat more than the new maintenance calories and gain.
So on and so forth. It's fascinating really how it works. Annoying too
I think the best thing is to followed the tried and tested routes...
Best way, but I have to say since the question was about how VLCDs such as Cambridge work, that Cambridge is probably the most researched diet in the world.
But I'm not here to defend nor promote Cambridge. Wouldn't dream of it, just making sure no misinformation or misunderstandings spread around as a 'Super Moderator'
Stick with SW. I've done it many times in the past and thoroughly enjoyed it
Besides, I know that SWers generally don't like talk of calories on their forum, so hopefully all questions answered sufficiently