The idea of frequent fasting (intermittent fasting) is that once you got your body to run on ketones, (at least 3 days on water and air only) enough lipolytic enzymes will be produced to spare the protein by supplying adequate energy from ketones.
Lipolytic enzymes stay in the blood for at least 7-10 days. So if you go fasting (say 30hrs- 48hrs per week) after the initial first fast of say 3 day or more , it will be easier for your body to switch from the glycogen source of energy to fat source of energy bypassing some of the consumption of your amino acid (protein/muscle).
Another benefit is that, you know if you messed up and eat the wrong food, you get redemption when you start over. Here, the catch is you have to do it like longer time 10-15 weeks, to get the benefits.
If you are in need of curing an ailment best way to go is longer fast.