Hacker News Reader

Comment by 0xbadcafebee | Hacker News Reader

Different intermittent fasting regimens result in different results re: losing lean muscle. The longer intermittent fasting cycles seem to show no significant loss of lean muscle. (i'm way too lazy to go find the studies to back this up claim, but they're out there somewhere)

View on HN

> The longer intermittent fasting cycles seem to show no significant loss of lean muscle. (i'm way too lazy to go find the studies to back this up claim, but they're out there somewhere)

Absolutely wrong: https://news.ycombinator.com/item?id=38194372

"Absolute" means "unquestionable, fundamental, ultimate, no exception", etc. You've linked to a single study which did not test all forms of IF. You can't say you know something absolutely if you haven't even tested for it.

Specifically, there are much longer periods of fasting which may have a different impact on the result which are not tested for here. There is a claim about alternate-day fasting which is actually not supported in the linked study.

In addition, the longer alternate-day fasting practices may include ad libitum which may have a detrimental effect. Lack of adequate protein is presumed by many to be linked to loss of lean muscle, and the quality and form of feeding during feeding windows would therefore be of high importance, but doesn't seem to be accounted for in these studies.

An old fashioned way of fasting preserves muscle mass way better due to hormonal response. It only kicks in after 30-40 hours of fasting. I don’t think that a lot if people practice 3-4 of fasting when doing IF.

Longer periods of fasting reduce testosterone, which probably negates whatever GH benefit it provides: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9182756/

And why would your body go out of its way to preserve metabolically more expensive tissue during longer periods of deprivation?

Any kind of caloric restriction lowers it temporarily. There is some evidence that testosterone levels can be even higher after the fasting https://josepheverettwil.substack.com/p/how-fasting-changes-...

Reply on news.ycombinator.com