our ancestors, hunter/gatherers were unintentional fasters; get nothing during the hunt? 'well, hun, we're fasting tonight'..
from the link you provided;
Surprisingly, since I've started intermittent fasting I've increased muscle mass (up 10 pounds from 205 to 215), decreased body fat (down 3% from 14% to 11%), increased explosiveness (set a personal best with a clean and jerk of 253 pounds a few months back), and decreased the amount of time I've spent training (down from 7.5 hours per week to 2.5 hours per week)
11% is flat out outstanding, visible abs territory. Clearly this worked for him . He likely plateaued --- took a shock to the system to get to the next level. This is one of its benefits.
It's very individualistic. Certainly, for some it can be a poor decision (ex., hpa axis dysfunction)
Of course , weight loss is the goal of intermittent fasting.I do think intermittent fasting and a ketogenic/or a low carb diet (low glycemic) would be your best bet to preserve lean muscle mass , force the body to use exclusively fat stores. In addition, there is evidence it provides a healthier cardiovascular blood profile (lipids/glucose/triglycerides )
when I do it...t's unintentional.
To press the re-set button I go on a ketogenic cycle for 3 months.