Yes, I think that one aspect of the dominant culture in the industrialized world is 'over consumption'. I do not think that over consumption is anything to feel guilty about, but I do think that it is dangerous to both our financial and physical health. Slowly I see a shift happening. Words like 'minimalism' and 'fasting' are popping up more and more. Perhaps after the next financial collapse and old word like 'saving' will return too!
But to the direct topic of fasting... yes, I think that fasting for prolonged periods of time (even up to a month) can be part of a healthy lifestyle.
I think that going longer than that without food... unless you have huge reserves of fat stored up before hand, would be detrimental to your health.
So far my longest fast was just over 24 hours. And as it was documented on the STEEM BlogChain I see that has already been 5 months!
https://steemit.com/longevity/@freedomengineer/fasting-part-3
I have fasted for 10 days with water, 3 days without on a dry fast. Both yielded amazing results and energy!