The Wellness Scoop - Bite-Sized: How Your Diet Affects Sleep

Episode Date: February 9, 2022

We’re joined by Guy Meadows, physiologist and leading sleep expert, to discuss why what we eat and drink has a profound impact on the quality of our sleep, and which aspects of our diet to focus on to support better sleep.   Here’s a short recap: The connection between diet and sleep Why a healthy diet supports better sleep The impact of caffeine, sugar, and alcohol on sleep Why when we eat affects sleep How sleep influences our appetite The importance of focusing on a healthy, balanced diet over specific nutrients   Guy Meadows: ‘The Sleep Book: How to Sleep Well Every Night’ https://sleepschool.org See acast.com/privacy for privacy and opt-out information. Learn more about your ad choices. Visit podcastchoices.com/adchoices

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Visit BetterHelp.com today to get 10% off your first month. That's betterhelp, H-E-L-P.com. Hi, I'm Ella Mills, the founder of Deliciously Ella, and this is our podcast, Delicious Ways to Feel Better. This year we've launched a new format with these short 10 to 15 minute bite-sized episodes which will hopefully give you everything you need to know in a really digestible practical format and each month we're going to be having a resident expert join us to delve deeper into one topic and the topic for February is sleep. So during February we're going

to be joined by Dr Guy Meadows, a physiologist who is a leading expert in the space of sleep. Guy founded the Sleep School which is a team of global sleep experts with over 10 years of experience. They use evidence-based and clinically proven education and tools to help everyone with chronic sleep issues to sleep better every day. Guy is also a published author and in his book, The Sleep Book, How to Sleep Well Every Night, he shares his method, blending mindfulness and cognitive behavioral therapy techniques to help readers sleep better naturally. So last week with Guy, we looked at why sleep is so important for our mental health, our emotional health and our physical health. And this week, Guy, I would love to delve into the links between diet and sleep. Could we start with the connection between the two and why what we eat could impact on our sleep?

Absolutely. So I think, you know, in the simplest terms, good sleep promotes, you know, sort of a healthy diet and a healthy diet, you know, promotes good sleep. It's a beautiful relationship, you know, very similar to the other sort of pillars of health as well. And so where does that sit? What is it that promotes better sleep? Whenever I start to be asked around, you know, sort of nutrition, I have to put my hand up and say, I'm not a nutritionist, because we get lots of people who come to our clinic, where they might need nutritional help. And I always, you know, I'm the first person to say, go and see a professional. But if we look at it from a simple perspective, what we can see is that any sort of food type, which is going to increase our level of arousal or stimulation, alertness. So, you know, caffeine, sugar, alcohol, etc.

Those are going to promote more sort of fragmentation, lower sleep quality, for example. If we have a diet which is going to promote, you know, sort of sounder sleep, then that's going to be more beneficial for us. So can we pick up on, because I feel that they're two of the most obvious questions that I'm sure people will be linking, the stimulants like caffeine. What is the link there between that and sleep? Are there any sort of, not necessarily rules, but guidance that we should have in terms of when to consume them and how they might impact on our sleep? Yeah, so caffeine is a great one because so many of us consume it every day. And it's, you know, I think a really important point about where we sit, you know, with sleep score is that we're, we're definitely not anti caffeine,

you know, it's because everyone goes, Oh, you must say, you know, don't drink any coffee, etc. Now, it's about just understanding the the science and having a bit of balance. So the thing about caffeine is that caffeine is the antagonist to adenosine. So adenosine is the sleepy brain chemical which builds up during the day. And so what we need to do is sort of accrue enough adenosine in our brain in order to be able to push us into sleep. Now, the reason why we like a nice cup of coffee is because caffeine masks the effect of adenosine, thus sort of giving us that boosted level of alertness. And so what we have to be aware of is that how much caffeine do we have in the system and how much, you know, sort of is that

going to affect our sleep? And so if we look at the half-life of caffeine, caffeine has a half-life of about six hours. That's the time it takes to remove half of the caffeine from the system. It has a quarter-life of 12 hours. So if we have a cup of coffee at midday, a quarter of that caffeine will still be in our system at midnight. And so that's a really sort of simple way of going, okay, you know, I need to ensure that I don't have too much caffeine in my system because that will impact my sleep drive, i.e. that lovely sleepiness that overcomes us and helps us to fall asleep. So as a simple rule, I will always say, you know, have maybe two or three cups of caffeinated beverage, whatever you like, but try to avoid it from midday onwards, switching to decaf or herbal alternatives. Now, some people listening, they might go, that just sounds ridiculous. I'm not

doing that. You know, and if that's the case, then look at where you are right now and go, as an absolute minimum, you've got to have six hours without caffeine between, you know, sort of stopping caffeine and sleep. But then ideally, if you can titrate it back, so if it's, you know, maybe if it was 5pm, make it 4pm, make it 3pm and see if you can just get a little bit earlier and that's going to help. Yeah, so that double espresso after dinner is not the one then? It definitely isn't. And there will be some people who are listening and, you know, a very short anecdote from when I used to work in research labs. We had someone come in. They weren't meant to be consuming caffeine. He snuck out to have a double espresso, came back in. We needed him in deep sleep to be able to conduct our research. He didn't get into deep sleep all night.

What he did was he just bounced around in light sleep. And when I woke up, I quizzed him, you know, sort of said, because obviously I've been awake for a long time now, waiting for this deep sleep to arrive. And he, you know, sort of confessed, oh yes, I had a double espresso. And so it really highlighted, he fell asleep, you know, which many people go, oh, I can fall asleep. He fell asleep fine, but he just didn't get deep sleep. So consequently, he woke up feeling unrefreshed and obviously went straight to the coffee shop again for another double and presumably that's not just specific to him that's what we see generally if you've got too much caffeine in your system you you might say oh well it doesn't affect me but even if you can fall asleep it is affecting your ability to get into those different stages of sleep and for

anyone who listened to our first episode those different stages of sleep where you're having a deep sleep are absolutely essential to various different biological processes that regulate a huge amount of your physical health, but also your emotional health. Exactly. Yeah. So we often say that the nighttime is a reflection of your daytime. And so, you know, what you have consumed, you know, from on a dietary basis will affect your sleep architecture. So how much time you spend in light, deep and rapid eye movement sleep. And so, yeah, you will be suppressing the amount of time you're spending in really restorative deep sleep or, you know, sort of psychological repair based REM sleep, etc. So yeah, it makes sense. sense and what about alcohol is that quite similar

alcohol unfortunately is definitely not a friend of sleep as a rule of thumb these days based on the wealth of research I say look if you want good sleep don't drink alcohol and so the balance I would give is well if you do like drinking alcohol you know for every night that you drink it have two nights off so that you're getting that good restorative sleep. And what we see is when alcohol is still in the system as we're sleeping, it's disturbing the quality of our sleep. Like you were just saying, alcohol inhibits your ability to get into rapid eye movement sleep, for example, and it leads to more sleep fragmentation. And so it just lowers the quality, reduces morning refreshment, etc. but the research is very clear even just a small amount of alcohol can have a large impact on our sleep quality so enjoy it but if you do drink try to leave at least

a few hours between drinking alcohol and sleeping consume water for example just to sort of you know dilute it down etc absolutely fascinating and are there any other things that we drink that we consume that have similar effect what about some people say you know having really really heavy meals just before you go to sleep does that affect your sleep absolutely this and these are these what i love about these these are all the kind of basics and yet you know the way most of us eat our food is we have the smallest portion in the day at the beginning and then we have a slightly big one then we have our biggest meal sort of before we're going to sleep. And actually, it should be the sort of other way around. Our evening meal should be the lightest and healthiest. And ideally, as a minimum, we want to leave at least a couple of hours between eating and sleeping. But you know,

it could be up to four hours, we want that sort of stomach emptying to occur to ensure that because you've got these two colossal biological systems, you've got digestion and you've got sleep and they're not friends. And if you've got a stomach full of food and you're trying to sleep, one of the things that one of the byproducts of digestion is obviously elevates our metabolism. Elevated metabolism increases our core body temperature. And we need a one degree reduction in core body temperature to fall asleep. So instantly having a stomach full of food can make delay sleep onset but then once the stuff the food is in the stomach as well then that increases the proportion of food which is converted to fat etc all round it's not good for our sleep it's not good for you know that our diet and we're going to wake up you

know more unrefreshed which as you sort of touched on before, will lower our willpower. And we know that if we're experiencing poor sleep, we're likely more likely to consume more calories. So it has a bit of a vicious cycle. And why is that? Why does poor sleep drive that increase in desire to eat more unhealthy foods and therefore end up eating more calories? Well, I mean, there's some absolutely beautiful science in this because sleep is responsible for managing our appetite hormones, leptin and ghrelin. And ghrelin is responsible for that sense of hunger. And leptin is responsible for our sense of satiety. So that sense of satisfaction and fullness.

When we are sleep deprived, that gets turned upside down. So we end up with more ghrelin. So we're more hungry and that we have less leptin. So basically, we're more hungry and we don't know when to stop eating. But then on top of that, we also get the mental sort of aspect. So it plays a really important role in managing our mental performance. And as I mentioned in the first episode that we did, it's really important for managing our prefrontal cortex.

And when we're sleep deprived, that gets knocked out. And that means that it will reduce our willpower, for example, it affects our ability to make healthy choices, it kind of, we stray from what we, you know, might believe is morally right, or, you know, sort of what we believe in. And so, you know, if your New Year plan was to, okay, I'm going to eat a healthy diet every day. And yet yet if you're waking up unrefreshed, it's going to be much easier to sort of perhaps break that diet earlier than if you'd got better sleep. willpower is really challenging for people and actually realizing a lot of those drivers are actually biological is is incredibly forgiving and helps you have a better understanding of where you're at but then you obviously read quite a lot in the media you know these are the six foods that will help you sleep is that real are there six foods we can eat to improve our sleep or is it more perhaps that there are foods that impair our sleep versus improve our sleep?

I'm really pleased that you brought this up because this is a, in our sleep clinic, this is one of the things which we see all the time. When we're working with people who struggle to sleep, chronic insomniacs, for example, the natural tendency is to want to control their entire lifestyle in order to try and get better sleep. And, you know, the sleepy foods come up all the time. And it's like, okay, well, we need to be eating pumpkin seeds, we need to be eating turkey, bananas, you know, have some warm milk, all of this kind of stuff. And we get our clients where they're completely obsessed over it. You know, they're drinking milk, and they hate this stuff. You know, they are, you know, sort of pushing down lots of

pumpkin seeds or whatever it is. And it's the unhelpful reaction to it is, I need this, otherwise I won't sleep. The reality is, is if you just look at the basic science, you might go, okay, well, milk has calcium and magnesium in it, which kind of natures tranquilizers, that kind of makes sense. And, well, pumpkin seeds, they have tryptophan in, which is a precursor to serotonin, melatonin, which both help sleep. So that kind of makes sense. But actually, when you look at what happens when you consume these and the process that those foods go through and how much of that end product actually makes it into the bloodstream,

you'd have to be eating quite a lot of it. And actually, what I like to do is just get people to stick to the basics, you know, have a healthy relationship with food, not sort of putting all of their eggs in one basket, so to speak, and be just going, okay, well, you know, I eat a healthy, balanced diet, you know, it's light and small in the evening, I leave enough time between eating all the stuff that we spoke about, rather than sort of obsessing over individual specific nutrients or food types. Is there an ideal time between dinner and sleep? Well, so I don't know if you're familiar with the work of Dr. Sachin Panda. He speaks a lot

about time-restricted eating. And his research says that we have this kind of window of opportunity in which to sleep. And it's this, you this you know ideally we should be eating all of our food in the daytime within a 12-hour window or less so that would say if you start consuming food at seven well then you want to finish at seven you know assuming you're going to bed at 10 or 11 that leaves you with three or four hours i think you know as a minimum you want to leave two hours between eating and sleeping but if you can leave a little bit longer and if you can consume most of your calories within a 12-hour window or less then that's going to be really beneficial for you know all of the sort of physiological parameters which go into making a good night's sleep makes a lot of sense so thank you so much guy if you missed last week

last week we were talking about the foundations of sleep and why it's so important for our health and next week we're going to be talking about the link between stress and sleep, which is something I'm sure a lot of us can relate to. So thank you so, so much. And we'll be back again next Wednesday. You're a podcast listener, and this is a podcast ad heard only in Canada. Reach great Canadian listeners like yourself with podcast advertising from Libsyn Ads. Choose from hundreds of top podcasts offering host endorsements or run a pre-produced ad like this one across thousands of shows to reach your target audience with Libsyn Ads. Email bob at libsyn.com to learn more.

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