[Toshi]

This is a thread regarding intermittent and extended fasting. Come hither skeptics and converts and let's discuss the evidence.

Envisioned topics:

• intermittent fasting
• extended fasting
• intersection of dietary habits when feeding with fasting
• sorting out the wheat from the chaff in the various and sundry claims about fasting, both good and bad

Teaser, noting that I didn't create this image and don't vouch for it personally:

Also, some reasons to NOT fast:

• Pregnancy
• Breast feeding (at least for extended fasts)
• Diabetic AND on medication for it (if diet controlled/"controlled" should be free and clear)
• Body dysmorphic disorder as a baseline or without significant body fat to begin with (for extended fasts)

 

[Toshi]

Some trivia to start with:

Angus Barbieri's fast - Wikipedia

en.wikipedia.org

Starting in June 1965, Angus Barbieri (1939 – 7 September 1990) fasted for 382 days. He lived on tea, coffee, soda water and vitamins, living at home in Tayport, Scotland, and frequently visiting Maryfield Hospital for medical evaluation. He lost 276 pounds (125 kg) and set a record for the length of a fast.

Before and after. That's him seated.

 

[Toshi]

Next up: Why oh why? I think this is the best video that sums it up:

But if you don't want to watch, here's my synopsis, more or less:

- every country that has adopted a modern Western diet has seen an increase in overweight, obesity, and metabolic syndrome (which ultimately results in type 2 diabeetus)
- in the US this trend started in the 1970s, coincident with the USDA food pyramid (low fat, high carbs) and the advent of snacking all the time (similarly low or no fat, high carbs, and vegetable oils since they're cheap)
- what we are doing is clearly wrong, and the advice that @Nick likes to offer of "eat less move more" doesn't lead to long term weight loss for the vast majority of people
- why that doesn't work in the 6 mo onward period is that the body adjusts metabolic rate to match food intake if one engages on a typical caloric restriction type diet--makes sense as an evolutionary mechanism
- the underlying cause for all of this, from the phenomenon of people being skinny-fat through morbidly obese people with full blown type 2 DM, is posited to be insulin resistance, in turn caused by the carb overload in our snack-filled diet and resultant permanently high insulin levels

Whew. So that's the overview of the problem. Why would fasting work? During fasting there's no food inputs by its definition, thus no insulin spikes. Insulin blocks the mobilization of fat, basically. Give the body a period with low insulin and then fatty acids from within fat cells can be brought out, changed back to triglycerides, and then oxidized into ketone bodies. This is the natural way to burn fat, and again insulin being present stops this regardless of how much or little fat one might have on their own frame.

It's all about the insulin, basically. (There are many other players, ghrelin, leptin, etc. but insulin is the biggest by far.)

 

[Toshi]

I sent @Nick a copy of The Obesity Code by the same dude as in the video (nephrologist at University of Toronto). It goes into much more depth, explores alternate theories and shows why they don't explain the data as well (e.g. thrifty gene).

What it comes down to in his view, and he treats people with kidney disease that's most often caused by type 2 DM, is that just about anyone can benefit from prolonged periods of low insulin. I saw in one video of his where he quoted that 72% (iirc) of the low-insulin effect can be accomplished by ketogenic diets, in which carbs are radically restricted (like what @stoney does). But nothing can top the full 100% achieved by... not eating.

For tons of details on how to not eat he has another book, The Complete Guide to Intermittent and Extended Fasting, I believe it's called. If a monkey is interested but doesn't have a local library that has it I'd send them a copy gladly. But it's not that complicated:

Step 1) Don't eat.
Step 2) ...
Step 3) Profit!

 

[Toshi]

There are many fasting regimens that people have proposed. There are limited data in humans to suggest which ones are best, but as per the chart in the first post there are a few generally accepted things:

1) If fasting for weight loss then what works for you is what matters.

That may be something like 16:8 intermittent fasting, aka time restricted eating. 16 refers to the length of the non-eating time, 8 the eating. So one might eat from 12 noon-8 pm, and nothing with calories outside of that (tea and coffee without cream or sugar ok).

It may be OMAD, one meal a day: 1-4 hours per day to eat one large meal of a normal day's calories, then 23-20 hours not eating.

It may be 5:2, where one eats 3 normal meals per day for 5 days, then on the 2 other days eats 500 calories max, so a "fasting lite" kind of thing.

2) If fasting for longevity or other health benefits then longer fasts are probably more beneficial, extrapolating from mouse data. Yes, there are many other health benefits as shown in models from yeast through mice: mice fed every other day live 30% longer, yeast live longer, incidences of mouse model Parkinson's and Alzheimer's disease are reduced, and in one mouse trial alternate day fasting was as effective as chemotherapy in treating glioma (!) of the brain.

Anyway, if this is your goal, if you don't want or need to defatten, then longer is thought better, again based on measurements of autophagosomes in mice--we can't measure these in people non-invasively. Longer in this setting means something on the order of 24-120 hours, probably more on the 48 hour order. Again see the dude who fasted for 382 days--you'll be fine for 48 hours.

 

[Toshi]

Finally, before responding to the peanut gallery that I hope will see this tomorrow and chime in with their questions, a few thoughts of my own:

1) Hunger isn't something that is consistent and gets worse over time. It is cyclic (for me normal mealtimes + 9-10 pm) and the sensation goes away on its own in an hour or so whether or not I eat.

2) I've done several longer fasts: multiple 42 hours, several 66 hours or so, one for 98 hours. Day 2 has less hunger than Day 1, and Days 3 and 4 less yet. (This is as ketosis ramps up.) Day 2 is weird because noradrenaline and cortisol levels are high so one feels kind of buzzed. Day 3 and 4 are very calm feeling.

3) I have been bike commuting and mountain biking fasted. I like this. My head feels clear and I feel fine. I make sure to not do any extended anaerobic efforts, though.

4) Fasting longer than 16-18 hours is definitely easier when one starts out from a baseline of at least a moderately low carb diet. I define this is maybe 100g carbs/day or less. People say one is carb adapted or fat adapted. @stoney is fat adapted as he eats basically no carbs, and I effectively run on no carbs whenever I'm long enough in the fast for glycogen to be depleted in my liver and muscles.

5) Fasting doesn't decrease the metabolic rate. Indeed it actually increases it, at least on the order of 4 days for extended fasts and periods of weeks to months for alternate day fasting. See "day 2" phenomenon under point 2 above.

6) Fasting doesn't cause protein wasting. This is addressed in the video in the first few posts, but the long and short of it is lean mass is better preserved than with other ways of decreasing fat, and periodic growth hormone spikes are increased so the body is better set to rebuild what may be lost or turned over once one eats again.

 

[Toshi]

@Sandwich any input? @SkaredShtles how long has it been since you last ate? 2 hours?

 

[Kevin]

Ive tried a couple of times but couldnt do it.
I absolutely believe in the benefits.
Bu I think Intermitted fasting is a really good id if youre working a desk job or something.

 

[Toshi]

Ive tried a couple of times but couldnt do it.
I absolutely believe in the benefits.
Bu I think Intermitted fasting is a really good id if youre working a desk job or something.

What did you try, 16:8? Just got hungry?

 

[Sandwich]

I've been doing IF in the format of 5:2 fasting since January. I've dropped 27.8lb. Two days a week, usually Monday and Thursday, I eat 600 calories or less. It was really hard at first, I'm not going to lie. The first two months were a giant challenge, but I also saw pretty incredible weight loss during that time period. I lost about 1.5lb per week, then that figure reduced, then I hit a pretty constant plateau for a while. I stuck with it, and my average is now around 0.75lb a week when I have a successful 5:2 week (ie no illness or vacation or anything else). I have purposefully not maintained my diet on the off days. I didn't want to not be able to drink beer or eat tacos.

Currently, I don't really have any issues not eating. I used to be one of those people that was wondering when lunch was at 9:15. I still love food, but I can just work from 9-1 without stopping to eat and be OK with it, which is not something I could do in January. A side benefit has been that I'm pretty satisfied with like 1/2-3/4 of the food I used to eat. I'd always go back for seconds or have a huge bowl (one chipotle burrito was never enough) but now I'm struggling to finish. At part of the quest to lose weight, I've become more active in general, starting spinning classes 3 days a week and usually getting 20-30mi on the road bike each weekend.

For me, fasting was an essential first step. Without it I'd probably still be fat and not very excited about exercise. Now, I'm so close to the goal I set for myself in Jan (30 lb) that I can see cutting it out for a while once I'm there, provided I stick with spinning and riding. The biggest challenge now are the migraines I get all the time while fasting or after. I keep narrowing down my triggers but I just can't beat them. If I had confidence I wouldn't get a migraine, I'd be able to fast for 48h without issue at all. I just never know when one will strike. I'm going to grab some electrolyte pills today, if I make it to the drug store.

I still get a little lightheaded in the afternoon, by the way. I know you said you don't, but I always feel a little shitty by the time I get home from work (like 20h since my last real meal). I usually feel pretty sharp mentally, but I do NOT feel like running around, or chasing the kids, or doing much of anything. I pretty much want to hide until I can feel normal again.

 

[4xBoy]

I'm thinking about trying this, I can't seem to really lose weight, well, I dropped from 200 to 187 currently, but I would like to be at 175.

 

[Nick]

- what we are doing is clearly wrong, and the advice that @Nick likes to offer of "eat less move more" doesn't lead to long term weight loss for the vast majority of people

To be clear that isn't what I've said. I believe in exercising to a calorie deficit, not dieting to a calorie deficit.

Got ther book yesterday. Thanks! I'll chime in as I dive into it.

"Staying" at a healthy weight requires adaptation as you get older. I imagine statistics would show those who lose weight through fasting are likely to gain it back once they stopped the practice, much like you say those who lose weight by exercise may gain weight when they stop exercising.

Id argue It's easier to maintain exercise as your long term lifestyle than it is fasting.

 

[Sandwich]

That's pretty good dude. IF might help, sure, but it sounds like you're on the right track.

One other thing about IF is that there is plenty of scientific research out there about how caloric restriction helps significantly in a variety of diseases. I know that IF is not the same as CR, but it's not dissimilar either. I was just reading a paper about how CR mimetics can impact cancer... imagine being able to just get a patient to fast/ go on CR for a couple of days and improve his prognosis. Prior to where I am now, I was working in a metabolism startup, and a few people did IF with success, and again the process makes sense scientifically.

I'm not going to wax philosophical about diet any further, but evolutionarily it certainly doesn't make sense that we now have 24/7 access to massively sugary, fatty snacks to satiate us at a moments notice. Ditching carbs is virtually impossible with our dietary choices these days. I'm not sure that keto/paleo/whatever is the way to go, but it makes it pretty obvious how obesity is such an epidemic.

 

[4xBoy]

My sugar/corn syrup intake is crazy high.

I also really like beer.

Eating better is my big challenge, finding time to work out more is also a real problem, being perpetually broke doesn't let me work less.

 

[Toshi]

I'm thinking about trying this, I can't seem to really lose weight, well, I dropped from 200 to 187 currently, but I would like to be at 175.

My sugar/corn syrup intake is crazy high.

I also really like beer.

Eating better is my big challenge, finding time to work out more is also a real problem, being perpetually broke doesn't let me work less.

I would definitely give IF a shot! Given that you admittedly are eating a lot of carbs and sugars in particular I'd start with 16:8 as anything longer will likely be difficult with that diet.

An easy way to limit the sugar and refined carbs simultaneously would be to not eat anything made with vegetable oil (which one should limit sharply anyway, as it's high in omega-6 fats that are pro-inflammatory, like an anti-omega-3). That'll automatically cut out most things that come in foil pouches or cardboard boxes, and there ya go.

Re being broke: if you fast you'll likely end up saving money... eat the same or a bit more in an eating window but skip a whole meal (or many).

To be clear that isn't what I've said. I believe in exercising to a calorie deficit, not dieting to a calorie deficit.

Got ther book yesterday. Thanks! I'll chime in as I dive into it.

"Staying" at a healthy weight requires adaptation as you get older. I imagine statistics would show those who lose weight through fasting are likely to gain it back once they stopped the practice, much like you say those who lose weight by exercise may gain weight when they stop exercising.

Id argue It's easier to maintain exercise as your long term lifestyle than it is fasting.

Ok. In the book he cites a study that describes how ad lib eating increases after exercising, after "working up an appetite", if you will.

Plus there's the data from The Biggest Loser study, where those super fat individuals worked out like mad both during the show and for 6 years after, and all but 1 regained much of the weight, 5 of 13 ending up higher than pre-show baseline iirc. They also had caloric restriction and the resultant unwanted metabolic adaptation so maybe that was to blame, but it also shows that the conventional caloric restriction approach still is associated with metabolic adaptation even if one exercises a ton.

That's an interesting question re long term effects of fasting if one stops it. I don't know of any good data. One possible mechanism for why your theory may not be true, though, is that fasting ultimately is seeking to address insulin resistance. If one resensitizes one's body to insulin that effect may be more persistent over months or years--I don't know but it's plausible, imo.

And re ease: Skipping breakfast and not putting sugar or cream into one's coffee is pretty damn easy...

 

[Toshi]

One other thing about IF is that there is plenty of scientific research out there about how caloric restriction helps significantly in a variety of diseases. I know that IF is not the same as CR, but it's not dissimilar either. I was just reading a paper about how CR mimetics can impact cancer... imagine being able to just get a patient to fast/ go on CR for a couple of days and improve his prognosis. Prior to where I am now, I was working in a metabolism startup, and a few people did IF with success, and again the process makes sense scientifically.

Actually I think saying CR and IF "[are] not dissimilar" is a super understatement. A lot of the nominally caloric restriction studies are accomplished using alternate day feeding/alternate day fasting, I believe! And the evidence base is indeed very impressive, with studies off the top of my head showing benefits of CR/IF in various organisms from yeast through mice for:

- longevity
- cancer (lower incidences of various and sundry cancers, and one mouse glioma model study showing equivalent efficacy of extended fasting to standard chemo regimens!)
- obesity and DM2, of course, for those organisms for which this is relevant--no fat yeast afaik
- neurological function (with decreased beta amyloid in Alzheimer's mouse models, decreased Parkinsonian symptoms in mouse models, better maze solving in mice, increased BDNF/neuroplasticity/resistance to stress)

 

[Toshi]

Anecdotal datum: Since beginning fasting I've dropped a belt notch, and am halfway to dropping a second.

:feelsgoodman:

 

[SkaredShtles]

<snip> not putting sugar or cream into one's coffee is pretty damn easy...

Oh, HELL NO!

 

[Sandwich]

I am down 4" in the waist. I barely crammed into a gap 34, or a normal 35/36. Now I'm a 32 all the way around.

Some mouse studies also use what I would consider actual caloric restriction, visavis a specified low calorie diet (8 pieces of kibble a day) or a reduced calorie chow. It's an important distinction, though there are studies that specifically look at alternate day fasting or intermittent fasting.

I never really got down on OMAD or 16:8. It works for a lot of people, and I get that this is what is essential, but it's pretty much just caloric restriction and not truly fasting at that point.

As for people gaining the weight back, my opinion is that unless you ditch the "fat culture", you'll never be rid of obesity. 9 times out of 10 it's not my body telling me I need another burrito, it's my mind. Conquering the mental aspect is what keeps the weight off. I doubt very much that these people balloon up once somebody stops yelling in their face...they simply start making bad choices that lead to more bad choices and then the pounds add up...

 

[Toshi]

I never really got down on OMAD or 16:8. It works for a lot of people, and I get that this is what is essential, but it's pretty much just caloric restriction and not truly fasting at that point.

There are very limited data out there admittedly, but there does seem to be something crucial that happens ~12 hours, at least in this one dude with regard to trigylceride levels:

Skip to about 16:00 in if the embed doesn't take you there.

 

[4xBoy]

I'm thinking I might be able to drop some pounds, will I keep them off? I don't know.

 

[Kevin]

What did you try, 16:8? Just got hungry?

Yes I tried 16:8, thats the minimum amount of time you need without calories to my understanding?
I get up at 0500h on weekdays and dont sleep till 11 usually so its just a really long haul.
Ive traded my breakfast in for coffee but I usually take my first brake around 9 because I start to get really hungry.

That would mean Id have to have dinner down before 1700h which I usually wont be able to make and I like to ride my bike or run in the evening and I definitly cant do that without eating at least some fruit or a shake afterwards.

 

[4xBoy]

The 16-8 is tough for me.

Would mean no food till 10am and no beer after 6pm

Tricky.

 

[Toshi]

Yes I tried 16:8, thats the minimum amount of time you need without calories to my understanding?

THere's probably benefit to even getting a solid 12 hour or 14 hour block. It's not some on-off thing.

 

[Kevin]

I do 12h pretty consistantly already I think, unfortunately Ive been out with an injury for 4 months now so I havent been working or getting any exercise so its hard to tell if its had any impact on my body.

I put on 4 or 5kg since my accident and just started doing work outs on the stationary bike at PT.
Actually did an hour and a half this morning which felt really good.

Ill try and look into the 12:12 online and see if that has benefits, but I think it can be pretty hard to quantify since theres so many factors that play into weight and energy.
I kinda thought you needed a certain amount of hours for it to be effective...

 

[Nick]

Random weigh in, down 9 lbs.
I try to not eat after 6pm, and almost never eat before 6-7am, so it looks like I get a 12:12 fast all the time!

 

[Jm_]

The key IME is staying active and doing something every day, not just going on a ride on the weekends. It doesn't have to be cross-fit every day or anything like that, but you have to make a change to an active lifestyle. If you are out on injury, find out what you can do, it may be more yoga-based or something, but in most cases someone could do something for a few hours each day. When I was recovering from foot surgery last winter, I did a bunch of research and found out what kind of exercises I could do sitting and lying down, using my knee-scooter to shuttle weights back and forth. It looked a bit comical at times, but I was able to slim down while recovering/maintain a lot of strength. Whether it's just going for a real long walk, a run, a ride, etc., if you can fit this into your schedule, IME, you reap benefits over and over.

The problem is as as society, we've let businesses, friends and family convince us that everything else is so much more important than taking care of ourselves. Gotta get married, gotta buy a house, gotta have children, gotta buy this, buy that, graduate, get a job, move to the city, blah blah blah. Many people are killing themselves to do all of this...literally.

I don't find eating to be that important...in the sense that you don't have to go to extreme measures, just avoid crazy unhealthy stuff. The problem more results from the above IMO, people cramming food down their throat to make up for the lack of action and distraction.

 

[Kevin]

The problem is as as society, we've let businesses, friends and family convince us that everything else is so much more important than taking care of ourselves. Gotta get married, gotta buy a house, gotta have children, gotta buy this, buy that, graduate, get a job, move to the city, blah blah blah. Many people are killing themselves to do all of this...literally

Nobody has ever convinced me of any of those things.

 

[Toshi]

I don't find eating to be that important...in the sense that you don't have to go to extreme measures, just avoid crazy unhealthy stuff.

You may well be of the minority (I’m guessing) that don’t have some degree of insulin resistance. But if you haven’t tried this or even thought about it with an open mind please don’t go shitting in this thread.

 

[Toshi]

Ill try and look into the 12:12 online and see if that has benefits, but I think it can be pretty hard to quantify since theres so many factors that play into weight and energy.
I kinda thought you needed a certain amount of hours for it to be effective...

looks like I get a 12:12 fast all the time!

Re 12 hours here’s a study that showed their demonstrated benefit (for breast cancer, which men can get! but rarely) had a break point at 13 hours with increasing benefits with increased length:

Prolonged Nightly Fasting and Breast Cancer Prognosis

Rodent studies demonstrate that prolonged fasting during the sleep phase positively influences carcinogenesis and metabolic processes that are putatively associated with risk and prognosis of breast cancer. To our knowledge, no studies in humans have ...

www.ncbi.nlm.nih.gov

The science is real, people. This one with questionnaires is weak evidence due to recall bias but see yeast, mice, etc.

 

[Toshi]

For Jim and other normal weight people there are potential benefits as well: mental focus, time savings with no food prep when not eating, oh and most likely lower risk of various cancers and neurological impairments. That, too.

Impact of intermittent fasting on health and disease processes

Humans in modern societies typically consume food at least three times daily, while laboratory animals are fed ad libitum. Overconsumption of food wit…

www.sciencedirect.com

 

[Jm_]

You may well be of the minority (I’m guessing) that don’t have some degree of insulin resistance. But if you haven’t tried this or even thought about it with an open mind please don’t go shitting in this thread.

I seem to do a lot of shitting.

The question I always have to ask is how many hours of exercise a day does the subject perform?

 

[Toshi]

I seem to do a lot of shitting.

The question I always have to ask is how many hours of exercise a day does the subject perform?

The best evidence that your theory here is incomplete for those with insulin resistance is from The Biggest Loser.

They worked out like mad and also did standard calorie restriction… and they had metabolic adaptation at the end of the 30 week show (that being a decrease in metabolic rate beyond that expected from the weight lost in and of itself). What’s worse is that 6 years later despite still being adherent they had even more metabolic adaptation and all but 1 had regained weight, an average of over 2/3rds of what was lost. 5/13 iirc weighed more at 6 years than at the beginning of the show.

They did “eat less move more” to the T and all but one failed from my perspective.

 

[SkaredShtles]

I'm starting to wonder if perhaps my unscientific (and sometime unintentional) method of just not eating breakfast and/or missing lunch is helping maintain my svelte physique?

 

[Toshi]

I'm starting to wonder if perhaps my unscientific (and sometime unintentional) method of just not eating breakfast and/or missing lunch is helping maintain my svelte physique?

It may well be!

 

[Brian HCM#1]

I've been doing IF since last February, and its been the easiest way to loose weight over a longer period of time. I've done the South Beach and lost a lot of weight quickly, only to put it on again after a few years of getting lazy. With the IF diet, I wanted to lose 10lbs, so I have to keep my caloric intake to approx 1950 a day. I've set my eating window from 12-8pm. The only thing I have in the morning is about 3 cups of black coffee, then just try to eat healthy. The good thing is with the IF diet, you can eat carbs. Plus you don't need to include a lot of cardio. I'm in the gym 3-5 days a week only lifting weights for 1-1 1/2 hours at a time depending on my schedule. The hardest part of the diet is getting started and going through the light headed period which lasts about a week - week in a half. After that its very easy. Keeping with it, you'll lose an average of 1-11/2 pounds a week, so its a slow method of losing weight, but effective.

 

[Sandwich]

How much weight have you lost, Brian? I was dropping a pound and a half at first, but that plateaued after a while, to a more consistent 0.8lb a week. I've been in it for the long haul though.

Speaking of which, I'm down 28.8 since January, and now sit at a "normal" BMI. That was my original goal, but I'd like to get another 1.2 in order to drop an even 30lb.

 

[Toshi]

Second a series of 2 videos:

They found that coffee + MCT oil actually increases ketone levels! Most other additives including black coffee by itself (video 1) and coffee + coconut oil are basically neutral, and coffee + ghee appeared to inhibit ketosis.

Related to their techniques: I’m still not sold on ketone + glucose monitoring for my own uses, because I’m not sure how it’d cause me to change much. Maybe if I hit an extended plateau.

Based off of these data I think it might be reasonable for me to add a bit of MCT oil to my morning coffee when on routine/normal-length (14-24 hour) fasts. Its addition might kill autophagy but might actually kickstart ketosis.

For longer fasts (36-96? hours) I would avoid coffee + MCT after the first morning so as to not disrupt the autophagy effects that ramp up after 24 hours.

 

[Toshi]

and now sit at a "normal" BMI

I’m going to get a repeat DEXA (for body composition, not for bone density) and resting metabolic rate test in mid December. I had such testing a few days after starting intermittent fasting so this’ll be a nice update.

On my initial testing I had high body fat (30.5% overall) but much less than one would expect given my BMI. On this follow up I hope that my body fat will be in the normal range, although my BMI will likely still/always be at least “overweight” nominally because that assumes a normal amount of lean mass relative to height.

 

[Sandwich]

yeah I'll be clear- I know BMI is not the most useful tool, and my doctor said I could stand to lose "a few pounds" but I felt like this was a concrete goal. 30lbs is totally arbitrary, primarily so I can say "I lost 30lb", but the "normal" BMI was for me....I still have jiggle on my belly and the pinch test yields a little...it's not like I'm on the verge of death. I'm hoping to fast for a few more months and then see how I do with my peloton schedule. I'm such a fan of that program that I'd probably do it 4 or 5 days a week, which would negate the need for fasting (AND make me stronger for riding), but I still like the percieved health benefits of fasting...so maybe 36h once a month or something to cut some weight/bring on autophagy....but let's see when I get there.