A (4:22)

Yeah, it was really interesting there. You mentioned that we have this 247 access now to light and food. And there's quite a beautiful contrast there between, you know, constant access and the rhythmical nature of our bodies. Right. We're not meant to have that constancy of access to these things. Right. We're meant to eat at certain times, we're meant to see light at certain times. And until very recently, that is what we would have done. And it's this kind of mismatch, isn't there? And it's, you know. Are you saying that everyone has an internal rhythm that, that has presumably been set in some way based upon their lifestyle and the way they're living, but ultimately it is internal. And our job, therefore, is to have external behaviors in our life that match that internal rhythm as much as we possibly can?

B (5:23)

Yeah, that's exactly right. And so circadian rhythms, very simply are the physical, mental and behavioral processes that are happening over a 24 hour cycle. And when we are viewing light at a phase of the natural light dark cycle, that puts enormous stress on our body. So we know this as, you know, viewing Light at night, for example, after the sun sets. Right. We're not getting enough light in the morning as the sun is coming up. So this basically confuses our system in that our internal clocks are become disorganized or don't quite know what to do. And this creates misalignment. And I think where we go a little wrong is I think we believe that there is enormous variability talking about the general healthy population in terms of our internal preferences. And indeed, when you put folks like us on a mountain with no electricity, we're all going to fall asleep within a half an hour of each other. And modernity has created an opportunity for us to be awake at 2am but it doesn't mean just because our system has adapted to it does not mean it's good for us.

A (6:45)

Yeah, what you said about we're not as varied as we might think. I'm so happy to hear you say that. Night owl, morning lark. I know they talk about chronotypes. It just doesn't fit with what I've seen. I've had patients who swear to me that they're night owls swear to me and say, okay, look, this is the consequence at the moment of you being a night owl. You know, would you like to change that? A lot of them will say okay, but is it possible? I said, okay, well, let's just try for a couple of weeks, you know, changing a few things. Light exposure in the evening being a huge one. Let's cut that out as much as we can. Let's get your dinner a bit earlier. Let's get you up early and get you outside. Right. It is amazing how many night owls suddenly say, oh, I'm doing really well as a morning lark. Now, I can't say that that's for every single person. Right. And I recognize that many sleep experts are saying that there are these chronotypes. But as you say, those studies where you go out camping or they go out to the mountains, when that happens and we're removed from artificial light, it all starts to sync up a bit better.

B (7:55)

Doesn't really does. And when people are trying to kind of incorporate a more stable sleep wake time, the most important thing is to wake up at the same time every day and view light, even if it means potentially having a bit of a shorter sleep. That same wake up time is absolutely critical for setting your circadian rhythm. Right. And dropping that melatonin at the time that you need to. Right. To fall asleep and stay asleep. That's like when we talk about the coaching piece of Circadian alignment, that's where you start. You wake up if you know, all right, I want to wake up at seven, literally, as soon as you wake up, get yourself out of bed and get out into the morning sunlight or the morning natural light. It doesn't have to be sunny out, but just you want to get out in natural light. You want to look up at the sky for at least five to 10 minutes and then go about your day, right? That's going to help set your circadian rhythm. Now, there are other behaviors that help entrain our circadian rhythm. So the timing of our meals. So when we're eating our food, when we are active and social, when we go to bed, when we wake up, we want to try to align these behaviors with the natural light dark cycle. So when we're supposed to be active in eating and sleeping, we want to try to do that in a way that's aligned with kind of these natural environmental cues.

A (9:22)

And when our circadian rhythms are disrupted, as they are for so many people these days, just shed a light on some of those consequences so that everyone listening can really understand. It's not just about feeling good in the moment. Of course it will help you feel good and give you more energy and more focus. But there are some quite serious long term consequences, aren't there, when we have misaligned circadian rhythms?

B (9:48)

There are. We know that there's an increased risk of metabolic disorders and metabolic dysfunction. We know that there is not a single mental health disorder that circadian rhythm disruption doesn't touch. So if we are chronically misaligned, our internal system becomes very confused. And this cellular miscommunication is really, I think, the basis of most disease and frankly, aging. And so the behaviors that have transformed my life are democratically available and free. I personally have been able to shift my circadian rhythm to, to an optimal kind of zone. And I have seen in my own experience, you know, as a coach, I was, you know, very much a night owl. You know, like, I was cutting film, like late into the night, I was sending emails, I was doing all sorts of stuff during the night. And, and, and I, I can see now that I had just literally adapted to a lower level of functioning. And I know this because, like, I didn't even know what I was leaving on the table. Like, it was just like, it's one of those moments where you're like, you know, I thought I was being so productive and I was, by all intents and purposes, very successful, you know, but when I look back on, like, my Health, I was a mess. It's completely transformed my life. Aligning my circadian rhythms.

A (11:17)

That is really empowering for people who think that the way that they feel right now is the way they have to stay. And it is simply not true.

B (11:26)

You can change.

A (11:27)

You can change anytime you want. Yes, for some people, it's harder than others. It can be challenging for people in different jobs and different points in their life. But if possible, you're saying, you know, what can I do? What choices can I make to harmonize my circadian rhythm in the context of my life as much as I can? And with shift workers, it can be more challenging. I know you did a series of beautiful Instagram videos which I would direct people to if they want to know your views on this. Right. And I think that's something we really need to look at as societies. Is there a way to change that? What can we do to help them? So we'll come back to that. But actually, a lot of the time it's not as hard as we think. We don't necessarily need a huge lifestyle overhaul. A few simple things done consistently, really very quickly start to move the needle. So understanding that we're all different, you're pretty confident that you can make a recommendation about sleep, wake time, about eating windows, about alcohol, like some universal recommendations for people. Yes, let's talk about alcohol. What have you seen in the data? Did you say food was worse than alcohol for impacting our circadian rhythms?

B (12:41)

It's second.

A (12:42)

Second to alcohol.

B (12:43)

Yeah. And I think like, what's tough about alcohol is like, it's not just impacting you the day after. It has like a five day tail.

A (12:55)

Wow.

B (12:56)

Yeah.

A (12:57)

So, okay, you're saying from the data you've seen and you're measuring people's heart rate variability and their load and their

B (13:04)

recovery, their respiratory rate, their activity levels, their. Yeah, so heart rate variability is an incredible proxy for just our mental and physical health resilience. Incredible proxy for that.

A (13:14)

Okay, so you know, what are we talking here? Because let's say someone has two glasses of wine, okay. And they feel that they were up a few times at night, they have a bit of a headache. The next day they're craving a bit more caffeine, they're extra hungry, but they decide to compensate. You know what? Today wasn't good. I'm going to go to bed early tonight, eat early, not have any alcohol, and they then get a good night's sleep the following day. I think most people would feel that they're back to normal the next day. It sounds like you're saying from the data that that's simply not the case for most people.

B (13:51)

Right. They probably feel better, but physiologically they're not back to their baseline.

A (13:58)

Wow.

B (13:59)

So if they're reporting drinking two plus drinks. Okay, so two or more drinks, it takes on average, five days to return to your baseline.

A (14:14)

Wow.

B (14:15)

I know.

A (14:16)

On average, of course, means that for some people that may be six or seven days, and someone else it could be three days.

B (14:21)

But that is exactly just average across hundreds of thousands. I mean, at this point, millions of data sets over the course of the time folks have been on the platform. Yeah, it's the average 2 drinks averages 5 days to return to baseline. And again, yeah, it could be two days for some, seven days for others. But this is where the problem lies. Right. Like you basically inside that window of five days, you could be having more drinks. Right. And so you just keep pushing then. That's basically what we see is, you know, folks who have, you know, history of, you know, pretty, you know, lots of alcohol consumption, they come onto the platform with very low heart rate variability.

A (15:08)

Wow. Yeah, we've all got a different tolerance level to alcohol. Okay, so from the data that you've seen, are there people out there who can maybe have a small glass of wine or half a beer in the evening and it not impact their sleep?

B (15:32)

Yeah, I mean, I think the key is to make it as far away from the time you intend to sleep as possible. That's where it just kind of seems to wash away and not impact your sleep. But I can say that from what I've seen in our data, which is massive amounts of data at this point, it appears that no amount of alcohol is good for your resting physiology.

A (16:03)

Okay, thank you for sharing that. Okay, so, I mean, that's pretty clear on your view on alcohol and what it's doing to us.

B (16:09)

It's so hard seeing the data. It's really striking. It's very hard for me to have any other point of view because I see it so black and white, clear as day.

A (16:22)

I think I saw that also when I was wearing a tracker, and I think I also, from recollection saw that. Wow, this is what a glass of wine is doing to your sleep. And once you've seen it, and I guess some people need to see it over and over again, but for me, I saw it to go, okay, I get it now. I can see what's happening. I can feel it subjectively and I can see it in the data objectively. So both of those things Together are sending me a strong signal. Now, I believe that you think a close second to sleep wake time is a regular eating window. Is that still the case? And if so, what is your advice or what are your recommendations?

B (17:00)

Right. Okay. So there's a couple things with the timing of your eating. So we see at population level, it is second only to alcohol in terms of its ability to disrupt our sleep and markers of recovery. So when we look at. When I say markers of recovery, I'm referring to heart rate variability, I'm referring to resting heart rate, respiratory rate. These are kind of our markers of recovery. And then sleep, referring to our ability to get into these deeper stages of sleep. So REM and slowly sleep and minimizing our awake time, we're going to have light sleep that's totally normal and desirable. It's important. There are really important things happening during light sleep. But we want to have about 40% of the time that we're spending in bed. We want to be in these deeper stages to restore. So the only thing that moves around our sleep more than alcohol is a late meal. And there's just no question that it has a negative impact on recovery and sleep.

A (17:56)

So for someone who, let's say, can't afford whoop and is like, okay, I want to implement stuff from what you have learned from all that data, but I can't go on that platform myself. Are there any consistencies as to food timing in the evening and its impact on sleep? Right. Some people are going to be more tolerable to a late meal than others. But, yeah. Can you make a generalized recommendation based upon what you've seen?

B (18:22)

100%. So, you know, there's lots of other kind of external literature that supports this as well. So this isn't, you know, just our research, but what we've seen is that. And typically, I'm not a nutritionist, I can just talk about the timing of things as someone who studies circadian rhythms. But once you fall asleep, what's happening mechanistically is you have a competition, Right, between digestion and sleep. They can't do both at the same time. Right. You're still gonna fall asleep, but you're not gonna be. It's kind of like alcohol. You're asleep, but you're not in these deeper stages of sleep. So that. And that's what we see in the data. We see that these late meals are compromising deeper stages of sleep. People are spending more time in light sleep by the tune of 30 to 50 minutes. So this is like meaningful amount of Time awake. Okay. And an average decrease in sleep efficiency by up to 17%. When folks are reporting late meals. Well, it's like wild, right? So food within two hour bedtime. So the recommendation is you want to try to back up your meal time so you're giving at least a two hour buffer from your last calorie to when you intend to sleep. So that's a really big piece to this kind of whole puzzle of also being able to maintain sleep consistency. Right. Different foods will potentially, potentially impair our ability to fall asleep. That said, I did a study with 700 collegiate athletes where we looked at pre sleep feeding and it looks like a bolus of protein that's bioavailable is not really going to impact your ability to, you know, fall asleep and stay asleep. I think it's if we're having that big Indian meal a couple hours before bed, that, that's, that's the one that's going to like kind of hit us hard. I think if people are eating, you know, low, low glycemic kind of foods, it probably is less important, right? I, I think it's really, if we're just eating really fatty, high carbohydrate kind of foods, you know, we're over fueling. I think that's when it becomes problematic eating later in the day. But I, I do think if we're eating really cleanly and we're keeping kind of our blood sugar at bay, I don't think that that's gonna have a huge impact on sleep and recovery. So I do agree that there's variability.

A (20:56)

Yeah, that's really interesting. So I agree. So on a personal level, a few years ago I did buy an OURA ring. I found that I learned within six weeks what it was gonna teach me. And one of the key things I still remember was a late dinner massively impacted the quality of my sleep. And I could see it on the data there. So here's the problem, right? Here's the problem these days is that you may want to live in perfect circadian alignment, but society isn't really set up to support that. Right. So for me, sitting down with my wife and children at the end of the day is quite an important family moment, right. So if you have a lighter meal, let's say you do eat with your family, this is what I do. Sometimes I'll have a, a soup or a bone broth in the evening. So it's a lighter meal even though I'm having it maybe closer to bedtime than I would want. So it's going to be easier to digest 100%.

B (21:58)

There's a phase relationship. And Dr. Samara Hatar, one of my. I just love him. He's done incredible research in the area of circadian physiology, circadian biology. But he says that there's a phase relationship between our activity, our meals, our sleep, you know, when we view light. And I think to ignore these relationships really comes at an enormous cost to our health and our functioning. So I think we have to respect this relationship and I don't think there's a single reason why we shouldn't try to optimize for it. And I think kind of goes back to just re configuring your family a little bit, you know, and I have a couple teenagers and we just have kind of reorientated ourself to be able to be more aligned with this natural light dark cycle. And you know, but I think we have oftentimes with our partner a lot of these like kind of hidden commitments that really I think pull us a little bit further away from maybe our ability to kind of show up in the world as, as we, as we want to. And maybe that's that glass of wine at 9 o' clock or, or 10 o' clock or you we have regularly and you know, thinking about, okay, maybe I can, knowing I want to maybe make some of these changes, maybe we can go on a walk instead. Or, you know, how do you kind of replace some of these behaviors that are getting in the way? And I, and I think so I think when folks maybe hear this conversation, like it's easy to get a little overwhelmed because they're thinking about all these commitments that they have with their partner and their family that kind of don't align with this way of living. But it's just a matter of, you know, just reconfiguring things.

A (23:48)

That's a great point. So zooming out. It's this theme throughout this conversation that we have a circadian rhythm. It's important as much as we can. And some people are going to struggle for sure that we match those external behaviors to our internal circadian rhythms. We can use a variety of different things to do that. Light exposure, food, timing, exercise, hydration, caffeine. Yeah, actually, if you can learn to master this, you kind of become a master of your physiology because you understand how to manipulate it, right?

B (24:23)

Yeah. I mean, I think that this is really, it gives us the foundation, I think, to live our values with, you know, joy and energy. I think that's kind of at a fundamental level what we're all after.

A (24:39)

Hope you enjoyed that bite sized clip. Do spread the love by sharing this episode with your friends and family. And if you want more, why not go back and listen to the original full conversation with my guest. If you enjoyed this episode, I think you will really enjoy my Bite Sized Friday email. It's called the Friday five and each week I share things that I do not share on social media. It contains five short doses of positivity, articles or books that I'm reading, quotes that I'm thinking about, exciting research I've come across, and so much more. I really think you're going to love it. The goal is for it to be a small yet powerful dose of feel good. To get you ready for the weekend, you can sign up for it free of charge@doctor chatterjee.com Friday 5 Hope you have a wonderful weekend. Make sure you have pressed subscribe and I'll be back next week with my long form conversational Wednesday and the latest episode of Bite Science next Friday.