> For a person who wakes up around 7am the fast should begin around 5pm in order to let the sugars deplete around bed time. There is no reason to have readily available sugars while sleeping.

This is not convincing. According to [1] it seems like system glucose utilization is only about 10-20% lower during sleep.

Muscles store even more glycogen than the liver btw (~500g vs ~100g).

1. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC293874/