There are those in the Paleo/Primal community who do intermittent fasting (IF) once their bodies have become accustomed to burning fat for energy. It works for them (some quite long-term), but many appear to be male. I've heard there is research that shows that this doesn't work as well for women but I've not read the studies myself as I am really not interested in going this route. Part of it is knowing our individual bodies and what works for us.