Good news, but people in Medicine are a bit slow in getting the very notion of 2nd order effect /Jensen’s inequality and disentangling mentally the first from the 2nd order effect. Which is why few are getting Antifragile or the more general sensitivity to scale of a distribution.
In the paper, Longo and associates saw health benefits from fasting that was NOT associated with reduction of calories, but solely from the variability (5 day fast compensated by subsequent boost in calories). So it is NOT the caloric deprivation but the convexity of the human body to change (over a specified range) that is the subject under concern. Luckily you can detect that without too many experiments given its mathematical necessity (the link between convexity and benefits of volatility).

This report missed the point. And look at the silly weight loss connotation.

http://www.sciencerecorder.com/news/2015/06/24/reverse-signs-aging-safely-5-day-fast-month/

Reverse signs of aging safely with 5-day fast each month
A stunning new study shows that intermittent fasting can slow the aging process, improve cognitive ability, and reduce the incidence of cancer, inflammatory disease, and bone loss.
sciencerecorder.com