Is there a tipping point?

I know many answers to the mysteries that are diabetes, but I've hit an odd one myself.
I am being particularly careful with carbs at the moment. Trying an Atkins "Fat fast" in an attempt to get weight moving.
It's good for BG too 8)
Night before last went to bed at 5.1, woke up at 6.4.
Last night bedtime 5.0 ~ morning 4.8
Is it a tipping point do you think guys. pobviously I prefer the second patterrn and wish I could stick to it
Hana

The mystery deepens. Last night 5.1 this morning 4.7[admittedly it was only just after 6.
Thanks for the suggestion Patch. I'm very low carb most of the time, but not normally so high fat. Didn't do too well, had some excess almonds. The fat fast is calorie counted and I know I went over the 1200. Still the first batch of my gym class slimmers were weighed this morning[my turn tomorrow; we didn't all start on the same day] one gained a pound and will pay the 50p forfeit and one stayed the same.
We've agreed to pay 50p into a kitty if we gain, to go towards charity.
Hana