The following Mark's Daily Apple article was written by Mark Sisson,

and is narrated by Tina Lehman.

Are long fasts worth the risks?

Intermittent fasting, schmittermittent fasting.

The hot new trend is the extended fast, eating nothing and drinking only non-caloric beverages for no less than three days and often as many as 30 to 40 days.

A mere compressed eating window this isn't.

If fasting for more than three days sounds riskier than just skipping breakfast, you're right. Long fasts can get you into trouble.

They're a big commitment. You shouldn't just stumble into one because it sounds interesting

or some guy on your Twitter feed wrote about it.

Skipping a meal or even an entire day of food makes evolutionary sense.

We weren't always successful on the hunt or with foraging.

We couldn't head down to Trader Joe's for shrink-wrapped steak,

sacks of apples, and jars of honey.

Reaching the Fed state wasn't a sure thing. Intermittent fasting, going

out of your way to not eat, even though food is available, is a modern convenience meant

to replicate the ancestral metabolic environment. But long fasts seem more evolutionarily

aberrant. The evidence from extant hunter-gatherers, many of whom live on

land far more impoverished and limited than our hunter-gatherer ancestors, indicates that outright

famine is rare. The Hadza may not eat honey and wild beasts every day, but there's usually

plenty of something to eat. Are there benefits to the longer fast, though?

What's the purported reasoning behind not eating for days on end?

The logic of long-term fasting.

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