Hello all, there has been a lot of interesting talk and research on the idea of Alternate Day Fasting(ADF). The research seems to show that ADF may offer many of the benefits that CR does but while still allowing for some lifestyle flexibility. ADF has been shown in mice and humans to improve many markers of disease and aging. But when looking at the human studies, I have not found any research that has shown these same benefits without concomitant weight loss. In many studies, the subjects were instructed to eat as much as possible on their feed days so as to maintain an isocaloric status but it seems that this was difficult to achieve and many subjects still lost weight. This leaves me disappointed. If subjects have been losing weight, then you cant rule out that it was simply just a modified CR regimen.

So with this in mind, does any one have any studies on *humans* that have maintained a isocaloric status and still showed an improvement?

And to the people who are practicing ADF, do you find it difficult to maintain your weight?

I don't have the reference handy, but recently a study found no life extension (in mice) with every-other-day (EOD) feeding, unless calories were reduced overall to CR levels.

In other words, if you fast every other day, don't pig out the other days.

Some thoughts on intermittent fasting and weight loss:

Alternate-Day Feeding and Weight Loss: Is It the Calories Or the Fasting?

A Year of Intermittent Fasting: ADF, Condensed Eating Window, Weight Loss, And More

Here's the one study on alternate-day fasting on humans that showed a positive result without weight loss:

Intermittent Fasting Improves Insulin Sensitivity Even without Weight Loss

I've also seen a couple of rodent studies where food intake and weight were apparently not changed but some positive results were nonetheless seen. I think Michael disagrees with me here, though -- he made a couple of good posts on this subject. There are many studies, however, where the animals just end up eating a little less and losing weight as a result, which means all the good stuff may just be due to CR. And I agree that intermittent fasting probably doesn't extend lifespan, even in mice (although there's one or two papers suggesting it does; I've yet to read them in detail).

There is a line of thought that it is not the amount of calories one consumes, but the stress of dieting that causes the benefits, both in CR and in other intermittent fasting/ADF regimes. So it would appear that if you stress yourself by going on a diet (such as ADF) then you would reap the same benefits of CR.

I run EODF now and then, sometimes for around 7 days. Occasionally I'll fast for 2-4 days as well. My weight varies +- 5lbs. by the week. I used to find gaining weight difficult however now I can both gain and lose weight quickly. Part of the reason I do EODF is to give my insides a rest though it's tough to say how much EODF helps due to various estimates on how long food takes to fully digest and the possibility of eating extra to compensate for the upcoming or previous day of no food.

Yes, I have seen that study however according to this paper, ADFs effect on insulin sensitivity seems to be the most inconsistent marker. So is everyone mostly relying on the animal studies? If so, Michael has posted numerous times about how this seems like a shaky ground for adopting ADF.

This post has been edited by Michael: Feb 18 2010, 12:25 PM

To be clear, there are apparently beneficial health changes in non-CR-but-EOD mice for at least some strains in at least some experiments. The point is, they don't ultimately amount to much, in terms of actually letting them retard aging or live longer as a result, as was claimed, argued, and widely accepted by lay life extensionists.

Well, of course we're mostly relying on rodent studies -- just like we are for CR. Do YOU have a century to wait for clinical trials? You gonna convince Congress to fund 'em, too ?

IAC, there have been some short-term studies on EOD in humans, which pretty consistently show that Calorie-neutral or ad libitum alternate-day-fasting in humans fails to deliver the health benefits seen in the short-term studies in (some) mice.

This post has been edited by Michael: Feb 18 2010, 03:31 PM

That would be nice but studies showing consistent effects on health related biomarkers would do

Go ad free, join ImmInst as a Full Member.