Alternate day fasting vs. caloric restriction?

November 8, 2013 8:12 AM

Does anyone have information about the pros and cons (in terms of fat loss, metabolic effects, and anything else) of alternate-day or intermittent fasting vs. alternate-day or intermittent caloric restriction (e.g. in diets like the 5:2 diet or the UpDayDown diet where on your "fast" days you take in 20% of your normal calories)?
posted by shivohum to Health & Fitness (4 answers total)

As I understand it, the 20% thing is an attempt to sugarcoat the fasting experience, research having shown that this is about as much as you can eat and still have your body react much as it would to a total fast.

Personally I find water-only fasting causes me a hell of a lot less suffering. My experience has always been that eating only a small amount of food triggers an intense grinding hunger that lasts for two to three hours; the hunger pangs I get from a full fast are easily damped down with a good swig of water and last ten minutes max.

As far as rate of weight loss goes: I've found that 5:2 (where the 2 are full fast days) was enough to drop from 157kg to 145kg over seven weeks, after which I observed no further loss for another seven. This is about as good a weight loss result as I've had from any other plan not involving Biggest Loser levels of punishment and misery.
posted by flabdablet at 8:45 AM on November 8, 2013 [1 favorite]

The research currently favors IF. This may be a good starting point.

I have had the same experience with water fasting as flabdablet.
posted by Tanizaki at 8:47 AM on November 8, 2013

I worked with two women who fasted on a 5:2. One of their husbands also fasted and had a similar experience as flabdablet and Tanizaki, except he continued to lose weight. He also cut down on beer. They cut out eating entirely (water fasting) as opposed to eating a little.

I fasted on Fridays for Lent a few years ago, and I found that not eating at all was much better than eating a little. I had the same experience as flabdablet. I'd eat a little and have an intense hunger.
posted by Ms. Moonlight at 9:15 AM on November 8, 2013

I'll join the chorus of water-fasting-is-much-easier. I'm following the Fast-5 plan.
posted by Johnny Wallflower at 10:53 AM on November 8, 2013 [1 favorite]