I don't agree. I fasted 100 days in one year. Fasts averaged roughly 1 week a month often followed by a week juice fast. a couple fasts were two weeks.
It wasn't until much later that i did a 21 day fast and at day 21 I dissolved kidney stones. Why wasn't this done in the previous 100 days?
Some things have to go the distance.
I've probably done 300 days or more fasting in the past 10 years. I still have adrenal fatigue, hashimotos, and Lyme. I'm convinced that only a complete fast will resolve these and the fast must be in a stress free environment.