2023-05-03 - Interview Dr. David Sinclair - Optimize Longevity - Personalizing Your Fasting Window

    From Longevity Wiki



    0:00 how does fasting work
    0:02 how is it how does it fit into different
    0:04 people's Lifestyles when should you
    0:06 start does it matter your sex does it
    0:09 matter if you work out these kind of
    0:11 things I think most people they don't
    0:12 want just one size fits all because they
    0:14 know that right fasting isn't for
    0:16 everybody and it's different for
    0:17 everybody to be affected
    0:21 [Music]
    0:41 okay great okay so I I've already uh
    0:44 I've already sort of you know reminded
    0:46 everybody about what we're talking about
    0:47 today
    0:48 uh and that we're going to try and focus
    0:50 the next 20 to 30 minutes on just
    0:54 fasting in their questions specifically
    0:55 about fasting I know that there are
    0:57 questions about everything else that you
    0:59 talk about
    1:01 um
    1:01 and a man and you know all the things
    1:03 but we're really going to try and focus
    1:05 on fasting today so that uh we can give
    1:08 you guys a handful of takeaways that you
    1:12 can you know leave this with and then I
    1:14 have a little surprise for you guys at
    1:16 the end
    1:18 um but oh it's then so to show you guys
    1:20 so should you why don't you start
    1:23 because obviously you're the expert here
    1:25 I will address some things about fasting
    1:27 and uh female health and fertility but
    1:30 uh we can get to that
    1:32 um you know towards the latter half
    1:34 great well it's great to be back on hi
    1:37 everyone thanks for joining
    1:40 it's nice to see you and uh yeah so
    1:42 today we're going to have a pretty quick
    1:44 uh session about fasting you and I uh
    1:47 have been talking about fasting for a
    1:48 long time
    1:49 um
    1:50 we talk about it a lot and we have
    1:52 actually we have we have some different
    1:54 views I'm I'm a male
    1:56 um sometimes I work out
    1:58 with different ages and so really the
    2:00 question I think we should talk about is
    2:03 uh how does fasting work
    2:06 how is it how does it fit into different
    2:08 people's Lifestyles when should you
    2:10 start does it matter your sex does it
    2:13 matter if you work out these kind of
    2:14 things I think most people they don't
    2:16 want just one size fits all because they
    2:18 know that right fasting isn't for
    2:20 everybody and it's different for
    2:21 everybody to be affected
    2:23 and actually I'd like to really
    2:24 emphasize that because some people don't
    2:26 actually know that so and that's
    2:28 definitely what we're here to sort of
    2:30 highlight that it isn't one size of it

    When should you start fasting?

    2:33 all
    2:34 at all keep that in mind
    2:36 well yeah so I started
    2:39 um skipping meals when I was in my 20s
    2:42 actually and so often I'm asked when
    2:45 should people start and the answer I
    2:48 think is well
    2:50 in your 20s actually you can start not
    2:53 eating three full meals a day
    2:55 especially if you are a nice healthy
    2:58 weight we're not talking about of course
    3:00 today we're not talking about
    3:01 malnutrition or starvation that's very
    3:04 important to to make that point but what

    How Dr. Sinclair combats a slowing metabolism

    3:06 I like to do in my whole life is to
    3:09 gradually reduce
    3:11 um not just how much I eat because I'm
    3:14 actually slowing down my metabolism now
    3:15 53 as a a couple of days ago but I also
    3:20 think it's important to gradually
    3:21 increase the period where you don't eat
    3:24 and re shorten the period where you do
    3:27 eat and that's why I would like to cover
    3:29 today
    3:31 okay we're on the same page with that
    3:34 yeah so I've um I I started my life in
    3:38 my 20s doing a lot of exercise I was
    3:40 working out at the gym I needed a lot of
    3:42 energy so I was eating
    3:44 um regular three meals a day and then I
    3:46 decided Well you know I'm not hungry in
    3:48 the morning so let me just skip
    3:50 breakfast and see what happens and put
    3:52 my calories into the later part of the
    3:54 day
    3:55 and that worked really well for me I
    3:56 didn't have this morning fog brain fog
    3:59 and I could power through the day I
    4:01 could learn my my lectures or not fall
    4:04 asleep during lectures in college and uh
    4:07 and so I've done that most of my life I
    4:09 rarely eat a big breakfast or breakfast
    4:12 at all and I think that's a that's a
    4:14 good way to start if you're young and
    4:16 you're considering trying to reduce the
    4:18 window of when you eat you could either
    4:20 eat later in the day so start eating an
    4:24 early lunch or a a lunch only
    4:27 um and then uh or if you if you don't
    4:29 like to skip breakfast you can actually
    4:31 skip dinner or at least reduce how late
    4:35 you eat but what you want to do and
    4:38 Serena we talk about this a lot is so if
    4:39 it's a clock you want to have an
    4:42 extended period that includes sleep
    4:44 because sleep is the easiest time to
    4:45 fast by far so either try to extend the
    4:49 time in the morning when you don't eat
    4:50 or at night before you go to bed foreign
    4:54 no I I absolutely agree and you know
    4:57 there are a few other factors that I

    Coordinating your circadian rhythm with a fasting practice

    4:59 factor into it as well and something
    5:01 I've chatted about with a colleague of
    5:03 mine who's you know the the sleep doctor
    5:06 uh but sometimes you know the time of
    5:09 the day that you're born can affect your
    5:11 personal circadian rhythm obviously
    5:13 there is a circadian rhythm that we go
    5:14 by because of you know the sun
    5:17 um but it's really about the window that
    5:21 you eat and the window that you fast and
    5:23 so for different people it's different
    5:25 things as you said for some people it's
    5:27 easier if you skip wrappers for some
    5:29 people it's easier you skip dinner
    5:33 the hours that you allow your body to to
    5:37 just digest and rest and be in a state
    5:41 where it's not an abundance as you
    5:43 always talk about uh David where it
    5:45 feels like it's in lack and for those
    5:48 people who are jumping on for the first

    Why to fast at all

    5:50 time who don't really know why we would
    5:52 fast at all
    5:54 um you know maybe you can give like two
    5:55 or three sentences of why fasting is
    5:58 good for you why it's great for
    5:59 longevity what is happening with your
    6:02 body in your body when you're fasting
    6:04 yeah
    6:06 well it's been known for thousands of
    6:08 years that societies who have a fasting
    6:10 period are more disease resistant and
    6:13 healthier in the long run so it's a
    6:15 tradition but science over the last 70
    6:18 years has shown that reducing not just
    6:20 the number of calories but actually when
    6:23 you eat
    6:24 um is super important for longevity and
    6:26 in in rodent studies where most of these
    6:28 Studies have been done and a few in
    6:30 monkeys and a few in humans but the
    6:32 rodent studies are very clear these are
    6:34 these are the conclusions that if you
    6:37 restrict the time period during the day
    6:40 which you give an animal uh to when they
    6:43 can eat it has a huge impact on their
    6:45 health and their Longevity if you say
    6:48 okay let's take the same number of
    6:49 calories and spread it out throughout
    6:51 the entire
    6:52 waking day or for a mouse to waking
    6:54 night it doesn't work as well you get a
    6:57 little bit of Health if you reduce
    6:59 calories but it's more important when
    7:02 you eat and it's also of course it's
    7:05 important what you eat it's you can't
    7:07 just eat terrible food and expect to get
    7:09 away with it but there was an amazing
    7:11 study done by a friend of mine down at
    7:13 the National Institutes of Health
    7:14 rougher to cover
    7:16 and he thought that he could find the
    7:17 optimal diet for a mouse and he put in
    7:19 different quantities of protein and
    7:22 carbohydrates and fats and after
    7:24 studying over 10 000 Mice found that it
    7:26 really didn't matter what they ate so
    7:28 much they're all healthy relatively
    7:29 healthy diets but the combination of
    7:31 ingredients didn't matter it was
    7:33 actually when they eat and it was eight
    7:35 eight during the day and it was the the
    7:37 one hour window that they got that these
    7:39 mice lived a whopping 35 which is
    7:42 Imagine imagine we could do that
    7:44 um and so that and other studies looking
    7:46 at the amount of calories and when my
    7:50 seat typically has told us that very
    7:53 likely
    7:54 we're eating too often and that's why we
    7:57 fast we believe that when we're in a
    7:58 state of adversity or at least perceived

    How fasting effects longevity genes

    8:01 adversity our bodies turn on protective
    8:03 genes they turn on the sotoan genes that
    8:06 we've worked on for 20 something years
    8:09 and there are other genes such as mtor
    8:11 gets down regulated ampk gets
    8:13 upregulated and these are longevity
    8:15 genes that protect the body we know this
    8:17 from from many many studies over the
    8:20 years in animals and in humans that
    8:22 there are longevity genes that protect
    8:24 us and if we sit around and we're always
    8:26 full or at least we're snacking on bars
    8:29 during the day and we're not moving our
    8:31 bodies say that's great we don't need to
    8:32 worry we can exhaust our our uh our
    8:37 bodies early our reproductive systems
    8:39 will actually age more prematurely
    8:42 um someone raised the question about
    8:44 fertility and I know you'll talk about
    8:46 it later Serena the one study that was

    Studies on fertility and fasting

    8:49 fascinating was that mice that didn't
    8:51 that restricted their feeding the
    8:53 females actually even though their
    8:55 fertility was not as abundant they did
    8:59 extend the period of which they were
    9:00 fertile so it does seem like there's
    9:01 this trade-off between calories
    9:04 longevity and fertility which we'll get
    9:06 into more later but really what I'm
    9:09 saying is you just want to make your
    9:10 body have a little bit of a threat to
    9:13 survival so it fights against aging
    9:16 yeah and so for anyone who's new to our
    9:20 chats uh when Dr Sinclair says adversity
    9:24 um and threat you know what he's saying

    What is adversity?

    9:27 is when we're not putting food into our
    9:29 bodies when
    9:31 um we're restricting that kind of food
    9:33 and intake
    9:35 um our bodies feel like
    9:37 um it's it's in luck and it's it's
    9:40 inadversity and so that's for anyone
    9:43 who's new to our type of chats that's
    9:45 that's what he that's what he's
    9:47 referring to
    9:48 um and um that's you know that's why
    9:51 it's good for a long longevity
    9:53 um
    9:55 I was just going to add that um it's
    9:58 similar to the effective exercise and
    10:00 cold therapy and you know and and sauna
    10:03 these are all the types of adversity
    10:05 that we're learning uh puts the body
    10:07 into a defensive state that fights
    10:09 disease
    10:10 yeah and and um again for any any
    10:13 newbies out there and also music when
    10:15 we're stressing our bodies out when
    10:18 it's like you know how cold punch can
    10:20 feel like
    10:21 awful you know when you're in it and so
    10:23 you're out of it or uh you know the type
    10:26 of exercise that seems like a really
    10:28 taxing your bodies and of course more
    10:30 fasting and we may feel like we're
    10:32 starving ourselves it's that stress and
    10:35 that sense of adversity that we're
    10:36 giving our bodies alongside that we're
    10:39 also allowing our bodies to kind of heal
    10:42 you know giving it a break to
    10:45 um you know to kind of rest recover
    10:49 detox which supports other benefits it
    10:52 supports gut health it supports brain
    10:54 health it supports our immunity all
    10:56 which lead to
    10:58 longevity and lifespan so so so now that
    11:02 you know there's a little bit of
    11:03 background for people who maybe are
    11:05 don't know you know what we're talking
    11:07 about today and just happen to jump on
    11:08 uh let's talk a little bit about the
    11:11 windows uh I don't have my messages here
    11:14 but just you know what feels good
    11:16 um what what 12 and 12 mean what 16 and
    11:20 8 mean I know that you've also talked
    11:22 about
    11:24 um you know 20 and four even uh and so
    11:28 and so if if there are differences on
    11:30 average and I know we talked we said
    11:32 it's individualistic
    11:34 um but just to give some people some
    11:35 insight so that they can figure out what

    Optimizing your fasting window

    11:37 works for them and how to figure out
    11:39 what works for them mm-hmm right so if
    11:43 you hear these numbers that Serena just
    11:44 mentioned they're talking about the
    11:46 window of eating so uh for instance the
    11:49 the 16 hour window you'll hear people
    11:51 talk about that mean typically means you
    11:54 want to skip or you're skipping
    11:55 breakfast and having a late lunch which
    11:58 uh is what a lot of people can do if you
    12:01 go further you can do 18 hours a day and
    12:04 some people go to 20 hours a day and
    12:06 then you just you know four hours is
    12:08 still you know one meal and it's all
    12:10 also called omad is up one meal a day
    12:13 but importantly I I always want to put
    12:16 with adequate nutrition so if it's
    12:20 confusing 101 then the larger number is
    12:22 the number as the our the larger number
    12:26 applies to the hours that you're not
    12:27 eating so 16 over the hours that you're
    12:30 not eating and then um eight would be
    12:32 the hours that you can't eat yeah and so
    12:35 that's what we're referring to when
    12:36 we're talking about the numbers and uh
    12:39 yeah Dr Sinclair was talking about one
    12:41 meal a day we differs just slightly
    12:44 there because I'm really more about
    12:46 eating within that window and it can all
    12:49 come in one meal as David said if you
    12:53 get a nutritionally dense meal and if
    12:55 you you can't get it all in one meal
    12:57 it's okay to have more than one meal
    12:59 just as long as within the eating window
    13:01 of you know eight hours or six hours or
    13:05 four hours whatever it is that you're
    13:07 doing
    13:07 yeah you also want to match your fitting

    Coordinating your diet with your circadian rhythm, and why consistency is important

    13:10 to your circadian rhythms
    13:12 um turns out these longevity genes that
    13:14 we work on the sirtuins they actually
    13:16 control the clock and if you've ever
    13:17 heard me talk about NAD this molecule
    13:20 that is essential for life and Longevity
    13:22 it also goes up and down with the day
    13:25 and what you eat controls your NAD
    13:27 levels and if you start to eat
    13:30 fairly uh irregularly let's say one day
    13:33 at breakfast the other day you have you
    13:35 you know you skip breakfast and then you
    13:36 eat a big dinner and the next day you
    13:38 skip dinner it'll it'll make it's not as
    13:40 good as being consistent actually
    13:42 because what's going to happen is that
    13:43 your your sleep wake cycle and you're an
    13:45 NAD cycle is going to get out of whack
    13:48 and you might even feel jet lagged
    13:50 um so that that's an important thing and
    13:52 there was actually a study in mice that
    13:54 if they they fed the mice in periods
    13:57 when they would not normally eat let's
    13:58 say they only gave them some food uh
    14:00 when they're asleep and made them go and
    14:02 get that food they didn't live longer so
    14:04 timing of this is very important so I
    14:07 try most days to match it and so I like
    14:11 to eat most of my calories if I can
    14:13 around dinner time try not to go too
    14:16 late if possible uh and then fast
    14:18 through the night and have very small
    14:20 amounts of food up until then if
    14:23 possible oh and so I just want to
    14:25 mention if possible because I'm not
    14:27 perfect at this you know you've seen me
    14:28 eat before
    14:30 um I typically have a little bit of

    Is coffee going to break my fast?

    14:32 yogurt in the morning because I have
    14:34 polyphenols that are insoluble and I mix
    14:37 that so it's okay to have a little a few
    14:40 bits of calories you can have a coffee
    14:41 with a bit of milk this is not going to
    14:43 break apart terribly and your body will
    14:46 still I believe and the results say from
    14:48 the lab that you'll still still get the
    14:50 benefits but often when you're starting
    14:52 these uh how about we talk about how
    14:54 difficult this is and how to make it
    14:56 easier
    14:57 yeah that's actually that's that's great

    Making fasting easier for you

    15:00 um to kind of segue there for people who
    15:03 you know for those of you who um are
    15:05 just used to having breakfast every
    15:07 single day that's sort of how you're
    15:09 brought up how your race how what knows
    15:11 kind of part of your your rituals and
    15:14 and how you go about your day I think an
    15:16 easier way to start would be try for 12
    15:19 hours and as David said include your
    15:21 sleep time so if you're sleeping for uh
    15:25 you know eight hours or or six hours or
    15:28 seven hours all you have to do is
    15:30 bookend it so that means starting your
    15:33 fast you know plus one plus or minus one
    15:37 or two or three hours before you go to
    15:39 bed and then adding on those other hours
    15:42 plus or minus on the on the other end of
    15:44 sleeping so again if you sleep for eight
    15:48 hours and you want to try fasting for 12
    15:50 then that means you just stop eating for
    15:53 two hours before the that sleep period
    15:55 of eight hours and then you add in two
    15:58 hours when you wake up where you don't
    16:00 eat and then really that's that's 12
    16:02 hours and you really only make an effort
    16:04 for you know for those hours and then it
    16:08 becomes easier she didn't just add
    16:09 another hour and just add another hour
    16:11 and if you do it on the bookends it's
    16:13 much easier and it doesn't seem as
    16:16 stressful or as a strain so
    16:19 um
    16:20 that's an easy way to do it yeah as
    16:24 Stephanie said it's easier than she
    16:25 thought so it really can be easier than
    16:28 than it sounds
    16:29 um just to answer a couple of questions
    16:31 that have come up
    16:32 um I do occasionally have drinks in the

    Dr. Sinclair’s fasting secrets

    16:34 morning uh athletic greens is one I've
    16:37 checked my blood glucose levels they
    16:39 don't go up at all when I drink it so
    16:41 for me I'm getting the vitamins and it's
    16:43 very low glycemic index
    16:45 um someone asked me what about a 72 hour
    16:47 fast or ask us about it 17 or two of us

    What does a 72-hour fast look like?

    16:50 are often done by people who really want
    16:53 to get a deep cleanse 72 hours is when
    16:55 deep autophagy or recycling of proteins
    16:59 it's called Uh kicks in
    17:02 um I've never actually been able to do
    17:04 that I can only go for a day
    17:07 uh but there are some people who can do
    17:09 72 hours and I think that if you do that
    17:12 um I would say every couple of weeks I
    17:14 would or maybe a month is more more
    17:16 reasonable
    17:18 um that would be great biologically to
    17:20 be able to clear out the body
    17:21 yeah and we can actually talk a little
    17:24 bit more about that if you guys have an
    17:25 interest there are 70 you know 24 hour
    17:28 fast 72 hour fast five days seven days
    17:30 and people have done 10 and 30 days
    17:32 there are different ways to do fast like
    17:35 that
    17:36 um and different ways to support your
    17:37 body when you are doing fast like that
    17:39 and so I'd want to dive into that
    17:41 properly so that you guys have the tools
    17:44 and the information to support you
    17:46 um but yes there are obviously benefits
    17:48 so as long as you do it the right way
    17:51 um and and water and liquids are super
    17:54 important in anything yeah you have to
    17:55 stay super hydrated uh so so yes
    18:00 um okay so covered that uh I know that
    18:03 some people uh about women's health I
    18:06 know we're kind of coming up on time so
    18:08 I did want to address some of that
    18:12 um about women's health and how to fast
    18:14 and as David brought up earlier it's

    Fasting in women

    18:17 different for women and men so how a man
    18:20 can fast is definitely different than
    18:22 how a woman can and he also brought up
    18:24 how it can affect fertility so you know
    18:28 as being most we require different
    18:30 nutrients at different times of the day
    18:32 different times of the month and it does
    18:34 have to do with our hormones
    18:36 um and we kind of have to modify this
    18:39 throughout our lifespan through the
    18:41 different chapters so as people move
    18:42 into menopause pre-menopause so cycling
    18:46 is sort of the best way in terms of
    18:49 fasting for women so the first and
    18:53 second weeks of your cycle you do want
    18:55 to do some sort of fasting
    18:57 um and that's and that's sort of your
    18:59 bleed weak and bleed after and the week
    19:01 after
    19:03 um for lack of a better term sorry all
    19:06 our to our male audience
    19:08 um but during these times we're much
    19:10 more resilient to
    19:12 um carbohydrate restriction so you want
    19:15 to be eating foods that are more for
    19:17 estrogen metabolism during that time and
    19:20 you want to prioritize those type of
    19:22 carbohydrates in the form of fiber rich
    19:24 foods we've talked about that before and
    19:27 we have content on that and we can dive
    19:29 into more detail if you want on another
    19:31 time
    19:32 um but that's sort of what you should
    19:33 keep in mind when you are fasting
    19:37 um and what you're eating during the
    19:38 fast and so and in your second week
    19:42 um your anabolic hormones they go up
    19:45 which is your estrogen and your
    19:46 testosterone and so you need to increase
    19:48 your protein intake a little bit and
    19:50 that can come in the form of animal
    19:52 protein or implant protein but just to
    19:55 be more mindful of that and then in your
    19:57 third and fourth week which is your
    19:59 ovulation week
    20:01 um your ludial week your body is in sort
    20:04 of a different hormonal environment and
    20:07 so you want to kind of focus more on
    20:10 resistant starches and when so when
    20:13 you're fasting to keep those things in
    20:15 mind you can't be as aggressive we can't
    20:17 be like the boys unfortunately because
    20:19 if we're a little bit too aggressive
    20:21 we've us for too long of a period of
    20:23 time we keep our body in ketosis we can
    20:26 actually produce more reverse T3 and
    20:29 that's not what we want to do and you
    20:30 can even make yourself insulin resistant
    20:32 so as females we just have to be more
    20:34 Mindful and be a little bit more gentle
    20:37 um when we during the different weeks of
    20:40 the month
    20:41 um in our ovulation in our Cycles so
    20:43 that's what I would say and it's not a
    20:45 blanket for everyone it's just to keep
    20:47 those things in mind and to support
    20:48 yourself while you're fasting
    20:50 um with those type of foods I and I
    20:53 think we're coming up close to time so I
    20:55 know there's a lot more fasting for
    20:58 vegan women I'm vegan I fast I do
    21:01 intermittent this intermittent fasting
    21:02 that we're talking about I try to pretty
    21:05 much do it every single day it's amazing
    21:07 fall off that's okay
    21:09 um but it's pretty much a daily a daily
    21:11 thing minimum of 12. I uh I I Target 16
    21:16 and that happens most days of the week
    21:18 uh and just to make sure that I get in
    21:21 those foods during specific weeks of the
    21:24 month
    21:25 I was just called a beast I'm not sure
    21:27 if that's a complimentary or not but uh
    21:29 thank you anyway uh just a few things
    21:31 I've seen come up I'll quickly
    21:32 addressing it for lack of time uh and a

    When to take NMN and how

    21:35 man and a man I take it in the morning I
    21:37 don't take it at night because you want
    21:38 your NAD levels to go up in the morning
    21:40 otherwise you'll you'll probably feel
    21:42 jet lag I take it with water you don't
    21:44 need food with that I'm currently taking
    21:46 a gram at uh well half a gram a day I've
    21:49 reduced it recently but I used to take a
    21:51 gram a day
    21:52 um Resveratrol I still take that in the
    21:55 morning with my inner man uh in the
    21:56 yogurt because that gives me my my Boost
    21:59 that gives me the energy and uh matches
    22:02 this Acadian rhythms
    22:03 um so yeah this is uh I think
    22:06 unfortunately we're running out of time
    22:07 three in a week because yeah for another
    22:08 few hours I know I think we'll have to
    22:11 wrap it up know that there's been a lot
    22:13 of comments just about how much we can
    22:16 we can kind of get in into a chat and
    22:19 sometimes we don't answer all your
    22:20 questions the most helpful thing is to
    22:24 either send messages you can send it to
    22:25 the community app you can send it to uh
    22:29 two direct messages and just flag that
    22:31 these are questions that you'd like to
    22:33 have answered in the lives
    22:35 um actually the best thing you can do is
    22:37 when we share that we are doing a live
    22:39 I'm usually on stories or on a post put
    22:42 drop your questions there and then
    22:44 that's really the ones that we're going
    22:45 to pull from
    22:47 um it's sort of the easiest for us and
    22:48 that way we can address questions and
    22:50 prepare for them because we do spend
    22:52 time and energy and love preparing for
    22:55 these for you guys so we want to serve
    22:57 you guys in the best way possible uh so
    23:00 that's it time does fly we're at 30
    23:02 minutes and so we're gonna wrap it up
    23:04 but we are going to do more of these yes
    23:06 we will save this for later as always we
    23:08 edit we clean up and we re-share and we
    23:11 repost and we still have our link up if
    23:14 you guys want to sign up uh for our
    23:17 series basically and get the notes for
    23:19 more chats
    23:21 and there's a burning question I think
    23:23 that I raised that somebody posted why
    23:25 would I reduce my anime levels
    23:28 okay
    23:32 um and so the the answer to that is
    23:34 um I'm trying different things I want to
    23:36 see what might work and and I want to
    23:37 see if lower levels will make any
    23:39 difference it's an experiment and we'll
    23:41 see how things go
    23:42 okay great all right thanks so much
    23:44 David thank you guys and thank you for
    23:46 all the things that I see here and we'll
    23:48 see you guys next time
    23:50 bye everyone