Just my 2p on VLCD and ketosis. First the medical definition of a VLCD is any diet that provides 800 kcal or less a day, so technically speaking 810 is not a VLCD, but 10 calories is nothing, believe me!
Also, you do not have to be on a VLCD to be in ketosis. Your body will enter ketosis whenever it needs to burn fat to get the energy it requires. Your body is lazy and will get its energy the easiest way possible - it will burn food taken in first, then glycogen, then body fat. All you need to do is to get your glycogen down, and then maintain that and a reasonable calorie defecit to be in ketosis. For example, I am currently taking in about 1100 kcal a day - 2 shakes a day, and a meal in the evening that is lo or no carbs. In the mornings I am in ketosis. I have tested later in the day and I remain in ketosis all day. I only drop out of ketosis when I eat my meal in the evening - and that is because my body is burning the ~650 calories I have just given it rather that burning fat. I have also worked out that if I go on the cross-trainer for an hour after eating, I can be back in ketosis before I go to bed.
As you may have guessed - I have been experimenting!