Good article/blog and there's plenty of tedious scholarly articles to further explain if you want to go there, which I encourage and do myself.
AND building on the article, when one fasts (dry fasting (DF) is even quicker: 1 day of DF'ing is like about 2-3 days of water fasting and other than being thirsty, DF'ing is easier) the body's autophagy process/activating ketosis and vise versa works even better/cleans the system quicker because it's self-eating the stored junk proteins as well as ketones from stored fat, rather than the proteins from food eaten. And the body hydrates itself with metabolic water which is stored in fat, so as the body hydrates itself it also then burns that fat up! AND plenty of junk gets stored in the fat, as well as those junk proteins, so the cleaning really amps up! AND the excess fat can cause insulin resistance, which can cause diabetes, hypertension, and cardiovascular issues, which can all affect hormone imbalances and cause other illnesses, as well as premature aging, so another reason why manipulated autophagy is great.
Gotta get used to the hunger and thirst, but as one builds tolerance, it's not so bad. Mind over matter. The brain is used to eating all of the time, but once the body goes into survival mode, some of that shuts down, and the body really isn't that hungry and can live on fat stores/junk proteins as this article discusses. Ketones are appetite suppressants. The body is amazing!!!
This is why I fast and when I eat, I eat keto. Major game changer--and I use to be a raw/vegan fruitarian and I'm glad I gave that up, as it wasn't working for me. There's a reason, many reasons in fact, why people and animals fast to heal. And when eating a ketogenic diet, one switches from one level of ketosis to even deeper, and therapeutic, level of ketosis when one fasts. (Fasting just means giving stuff up but not necessarily everything all at once. One can fast from sugar, alcohol, wheat, face book, TV, etc.) As far as fasting goes, all cultures do it. Humans have been fasting for thousands of years, for forever, and clearly with very good reason which the body is so intelligently designed to do.
Beyond all of this, the self-mastery and peaked energy levels are so rewarding in and of themselves.