Based on the book Fast Like a Girl by Dr. Mindy Pelz

PHASE ONE
Day 1-10 (from start of bleed to day 10)
Fast as long as you want. Eat keto when not fasting.

PHASE TWO
Day 11-15 (ovulation)
Intermittent Fast from 12 to 15 hours. (no more than 15 hours)
Eat food that serve your hormones. This is a non-keto diet higher in carbs called hormone-feasting.

PHASE THREE
Day 16-19
Fast as long as you want. Eat keto when not fasting.
If low progesterone or wanting to get pregnant see the book.

PHASE FOUR
Day 20-bleed
NO FASTING
Eat food that serve your hormones. This is a non-keto diet higher in carbs called hormone-feasting.