Hi Louisa,

I'm no scientist but I'll have ago at your question. There are many points which could be raised.
1 A lot of the initial weight loss IS water. Carbs cause the body to hold onto water and the body can hold quite a lot.
2 Weight loss might not slow that much or that dramatically.
3 Once your body has got rid of the water, it starts doing things with all that extra nice protein - like repairing muscle which may have been damaged by previous high carb low protein and fat dieting. And muscle is heavy.
4 With many people an extra 5 grams of carbs makes a huge difference. I can't go above 20 a day even after 2 years or I start to gain. (Most people aren't like me - don't worry!)
5. I don't think it's a 'loss of loss' as the real fat loss settling down to it's own momentum after the initial shocks your body goes through on induction.

I hope the above makes some sort of sense and goes part way to answering your question. No doubt other people will come along to give you a more full answer.

Good luck
Robert