That doesn't mean that a constant state of ketosis is optimal for healthy people. Someone pointed out that the difference between ketoacidosis and ketosis is like the difference between alcohol poisoning and a light buzz - well, being in a constant state of a light alcohol buzz isn't a good thing either.
https://articles.mercola.com/sites/articles/archive/2017/04/24/burning-fat-for-fuel.aspx
(Snip) "All of this can be avoided by cycling in and out of nutritional ketosis, basically going through a one-day-per-week fast and one or two days a week of feasting, where you eat double or quadruple the amount of net carbs.
Your body is designed to have the metabolic flexibility to use both glucose and fat for fuel. The problem is, most people lack the ability to burn fat. This metabolic inflexibility is the direct result of eating a high-carb diet for a long period of time.
As a result, they struggle with weight issues and poor health. Even if they are not overweight they may be "skinny fat" with loads of excess dangerous visceral body fat. Feast-and-famine cycling helps reestablish the metabolic flexibility to burn fat. Another important dietary factor is avoiding late-night eating.
Feeding your body at a time when it needs the least amount of energy will simply result in cellular damage due to the excess production of free radicals. For this reason, I often suggest limiting your eating to breakfast and lunch a "Peak Fasting" strategy that allows you to fast for 16 or more hours each day."
The author's primary point is to use using intermittent fasting to promote mitochondrial repair and weight loss and improve your health. This does not involve a high protein diet & uses small cuts of meat, nuts & more good fats like Olive Oil and coconut oil. Reduce carbs, Eat less for 5 days, more the remaining 2. Mediterranean diet stuff 2 meals a day, and take a day off from eating now and then.
As always people will have to make up their own mind on this. (We also had the "Be overweight and drink coffee and booze" article in the last few days telling us what we wanted to hear!)