Using starvation for weight loss essentially sacrifices (cannibalizes) more muscle than fat, making you skinny with higher fat percentage; unheathlier with each weight drop. The more you fast-to-lose, the more you’re slow-to-gain back muscle, recover from an illness, prevent an injury, and resist against disease.
Fasting is purely a biological “rest” from the 33% energetic burden of ingestion, digestion and elimination; cleansing those processes by its pause. Using fasting to lose weight is like removing bricks from the bottom foundation to thin the walls and build up the penthouse. We should rather apply fasting intuitively when we feel drag on a ship to scrape off the barnacles from the hull.
I discourage the use of fasting altogether until you get your quality of food choices and timing of meals, otherwise when you remove the substances you will experience difficult withdrawal symptoms. You don’t experience these symptoms when you pause after consistent quality food, because it does not contain addictive substances. So, fasting is actually ancillary to food quality and meal timing. Don’t scrape the barnacles off your hull, if they’re covering holes that will sink your ship. Instead, lay down new hull first from the inside and make yourself seaworthy.