Losing 1Kg a day - how come so much?

On my 5th fast I am losing more weight than ever - on average 1Kg (2.2 lbs) a day over the last 6 days.

I am grateful of course, since my primary aim of water fasting is weight loss. However I just can't understand the maths. I am a fairly sedentary person, though I have been taking a few walks to keep my lymphatic system working. I drink water only when thirsty. But they say the human body consumes 3500 calories per day which is equivalent to one pound of fat.

As I am fasting, I thought my calorie requirements would be less than 3500, yet the weight I am losing per day equates to 7700 calories per day (2.2 x 3500).

Touch wood, I hope this rate continues. But can anyone explain how I am losing so much weight? To me, the maths just doesn't add up.