Minimum time for IF benefits

Ryan T

More than 500 posts
Question has been rolling around in my head recently. How long do you really need to fast (obstain from all caloric intake that can produce a blood sugar response) when doing IF to reap any real benefits (eating at maintenance for the feeding window) for insulin sensitivity, leptin sensitivity, hormonal cascade/balance etc...? Lots of folks 'round these parts do 16/8 to 20/4 fasting/feeding windows. Tagging @kennycro@@aol.com and @mprevost as well.

Thanks.
 

Antti

More than 2500 posts
Since we're on the subject of IF I've been wondering how much the benefits of IF are dependent on total abstaining from food or from certain food groups. For example, I've seen IF recommended with protein shakes during the day with the short eating window late in the evening.
 

Sean M

Quadruple-Digit Post Count
Probably varies by individual, but my opinion is at least 12, probably 16. People 50 years ago ate on basically a 12/12 cycle, no snacking into a 4th meal (or 5th if you count a second evening snack session) we have now.
 

Bret S.

Quadruple-Digit Post Count
Certified Instructor
16/8 for me most days, I usually break the fast around noon, maybe a small snack in the afternoon (sometimes) then I eat most of my calories in a 2 hr window, this sets me up pretty well for the next fasting cycle.
 

Ryan T

More than 500 posts
Since we're on the subject of IF I've been wondering how much the benefits of IF are dependent on total abstaining from food or from certain food groups. For example, I've seen IF recommended with protein shakes during the day with the short eating window late in the evening.
Sounds a little like a protein sparing modified fast which would be closer to an undereating phase like the warrior diet. At that point I'm guessing you would only be reaping benefits of general caloric restriction while consuming enough protein to minimize muscle loss while in a caloric deficit. If you're truly eating at maintenance, then I don't see how it would benefit you more than just eating outside of a time restricted window. Again, looking to folks more educated than I but JMO.
 

mprevost

More than 500 posts
Question has been rolling around in my head recently. How long do you really need to fast (obstain from all caloric intake that can produce a blood sugar response) when doing IF to reap any real benefits (eating at maintenance for the feeding window) for insulin sensitivity, leptin sensitivity, hormonal cascade/balance etc...? Lots of folks 'round these parts do 16/8 to 20/4 fasting/feeding windows. Tagging @kennycro@@aol.com and @mprevost as well.

Thanks.
16/8 is proving to be beneficial in some trials. The growing consensus seems to favor that pattern, with the last meal in the early afternoon (skip dinner, not breakfast). Plus it is not too hard. I have not really looked at 12/12.

Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males
Effects of 8-hour time restricted feeding on body weight and metabolic disease risk factors in obese adults: A pilot study
https://www.sciencedirect.com/science/article/pii/S1550413118302535
 

Bret S.

Quadruple-Digit Post Count
Certified Instructor
16/8 is proving to be beneficial in some trials. The growing consensus seems to favor that pattern, with the last meal in the early afternoon (skip dinner, not breakfast). Plus it is not too hard. I have not really looked at 12/12.
Ooohhh.. Skip dinner.. tough one, schedule wise this is a no-go for me, this also flies in the face of Ori H's take in Warrior Diet, I'v tried straight Warrior but it doesn't work for people in physical jobs (at least not for me). My breaking fast meal carries me through 5-6 hrs, after fasting this mini fast insures quick digestive processing in my case, then I'm ready to put on the feed bag in the evening.
Many variables in play here
 

Ryan T

More than 500 posts
Thanks for providing the links here. I haven't looked at them yet but I don't think I could skip dinner with the family.
 

Ryan T

More than 500 posts
Hello,

It seems that in the Rhonda Patrick's opinion, this is about 12h:
Time Restricted Feeding: Your Solution to Longevity and Shredding Fat

Kind regards,

Pet'
Thanks for posting the video. Just got done watching it. The whole coffee/no coffee things throws me for a loop. I've heard it said before that coffee doesn't break a fast by major IF proponents who seemed to be well researched (like Thomas Delauer), but I've seen it posted here and now see in the video that coffee starts "the clock".

I've done time restricted eating a lot over the last 1-2 years but I've never experienced the magic body comp effects. Perhaps it's the coffee or it could just be a crap diet or excessive caloric intake...
 

mprevost

More than 500 posts
Ooohhh.. Skip dinner.. tough one, schedule wise this is a no-go for me, this also flies in the face of Ori H's take in Warrior Diet, I'v tried straight Warrior but it doesn't work for people in physical jobs (at least not for me). My breaking fast meal carries me through 5-6 hrs, after fasting this mini fast insures quick digestive processing in my case, then I'm ready to put on the feed bag in the evening.
Many variables in play here
There is some data showing increased inflammation with skipped breakfast but not with skipped dinner. This needs to be looked at some more and nobody knows yet how significant this is.

Impact of breakfast skipping compared with dinner skipping on regulation of energy balance and metabolic risk
 

LukeV

More than 300 posts
When I was a child my father worked evening shift and so we ate dinner as a family around 4pm and he would leave for work after. It always resonated with me and I largely stuck with that approach for years, until marriage and family. My wife prefers to eat later but we compromise and usually have 6.30pm dinner, occasionally I can get it at 6pm. But 4pm with a long overnight fast is still my preferred meal timing
 

Sauli

Quadruple-Digit Post Count
14-16h is seems to be good MED. 18h-20h fast is powerful, but still doable pretty much daily. OMAD gets pretty hardcore. Specially when you do it several days on row.
 

Al Ciampa

Quadruple-Digit Post Count
Certified Instructor
This needs to be looked at some more and nobody knows yet how significant this is.
“Probably” small enough to be ignored. This paper will be something to consider in a larger review, however, which you qualified in your post.

Why I comment is because on a public forum, the d and r in front of your name psychologically gives the idea in this paper far more emphasis to the average reader than if someone else posted it.

Just balancing the scale. Don’t rearrange your lives just yet. I’m my clinical experience, changing eating habits is the one positive lifestyle intervention that already has a lot of pressure against it: social, psychological, physiological, cultural, educational, etc. It is far easier to get someone to skip breakfast than supper.

Pointing out a paper like this might just add to the already overwhelming amount of pressure against change. I can hear someone coming into my office later today saying they can’t fast because a report said I need to skip dinner. And that’s the only meal my whole family sits down to.

W/r to diet and health, fasting is probably one of the most powerful and effective tools we have in behavior modification.

I know you know this Mike. As I said, just balancing out the scale for the average reader.
 

Ryan T

More than 500 posts
No sweat Al. That was entirely appropriate. Honestly, I am always surprised when someone puts too much stock in what I say. I've been wrong more times than I care to remember.
That's a great and humble thing to say.
 

Ryan T

More than 500 posts
“Probably” small enough to be ignored. This paper will be something to consider in a larger review, however, which you qualified in your post.

Why I comment is because on a public forum, the d and r in front of your name psychologically gives the idea in this paper far more emphasis to the average reader than if someone else posted it.

Just balancing the scale. Don’t rearrange your lives just yet. I’m my clinical experience, changing eating habits is the one positive lifestyle intervention that already has a lot of pressure against it: social, psychological, physiological, cultural, educational, etc. It is far easier to get someone to skip breakfast than supper.

Pointing out a paper like this might just add to the already overwhelming amount of pressure against change. I can hear someone coming into my office later today saying they can’t fast because a report said I need to skip dinner. And that’s the only meal my whole family sits down to.

W/r to diet and health, fasting is probably one of the most powerful and effective tools we have in behavior modification.

I know you know this Mike. As I said, just balancing out the scale for the average reader.
I appreciate this perspective. Maybe eating a smart, non-inflamatory diet that limits refined oils with a good balance of omega 6:3 ratio and time restricted consumption or IF (whatever...) could mitigate that risk.

EDIT: I was reading some of Jason Fung's work last night, and it seems pretty solid. I think I would need to get his book to really understand what he's saying. I am also not sure about how to fast for health and gaining strength at the same time.
 

elli

More than 2500 posts
Just a few thoughts:

- not eating for e.g. 12 hours does not mean being fasted for 12 hour.
- you digest 3-4+ hours (depending on what you have eaten) and you are not fasted - maybe 8 hours remain for a fasted state.
- having coffee for breakfast instead of real food is not fasting. coffee provokes a hormonal reaction in the body which is different from the ones in a fasting state.
- counting the time you sleep as fasting is not "real" fasting because not eating during your active time throughout the day is different from fasting during sleep for your body.

->my conclusion would be that not eating 12-X hours (ideally start counting after three hours after the last meal) during the day without any coffee (shakes, juices etc) could be called fasting.

- OMAD might be the diet which is closest to this but for the most of us pretty anti-social.
- maybe fasting for 24 hours 1/week (only water) might be better for those with a family?!

During the week I usually eat between 6.30am and 6.30 pm. At weekends I have breakfast later, no snacks and an earlier dinner -> shorter eating window.

what you eat and how much xou eat might be more important than when you eat :)


Anyways, I like these kind of threads!
 
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