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

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• Length: 24:12
• Interviewee: Dr. David Sinclair
• Interviewer: Serena Poon

Transcript

Intro

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