Best Diet & Time to Eat for Increasing Deep Sleep | Dr. Marie-Pierre St-Onge & Dr. Andrew Huberman

Diet & Sleep Relationship

00:00How does what we eat impact our sleep? This is something that I think most people have heard about in the context of try not to eat too close to bedtime. Um, this is an active debate in many households. Actually, some people seem to be fine eating close to bedtime and sleeping and even if they track their sleep, other people it really disrupts their sleep.

00:19I'm interested in both the timing of food intake relative to sleep, but also the content of the food and how it impacts sleep. what's known about that either from your work or from other work. When we started this conversation, I was telling you about these population based studies, you know, cross-sectional data where two things happen at the same time and you, you know, you you don't really know causality, they happen at the same time.

00:43And I think early on uh in this field we started thinking about sleep as the promoter of food intake or as a sleepcausing changes in diet exercise but didn't really think that maybe it's the other way around or maybe the other way around is just as plausible.

01:06So I started thinking about that and said well what what if we took the other approach? What if we looked at diet and examined how diet influenced future sleep? And my first paper in this field was using data from the multi-ethnic study of atheroscerosis.

01:25It's actually kind of [clears throat] hard to find good cohorts that have good nutrition data, good sleep data, and data over over years. Right? So MESA multi-thnics of study of atheroscerosis is one of those great cohorts that we have in here in the US that has all of the above.

01:44So I

Mediterranean Diet

01:48paired up with a colleague of mine Susan Redline in Boston and uh she's a principal investigator on their sleep ancillary study and we asked the question of diet quality and its impact on sleep duration, insomnia symptoms and we found that having a diet that more closely aligns with the Mediterranean diet was associated with better uh probability of having adequate sleep and reduced um insomnia symptoms in this cohort.

02:16So then it launched a whole field of study really to to keep looking at this and we've looked at this in different studies and different cohorts actually uh earlier this year we published data from the women's health initiative another large large cohort with good diet data and and sleep information.

02:35We took a really really nice approach in this uh longitudinal analysis. I don't know. Usually when we do longitudinal studies, we exclude people who have the condition at baseline, right? So if you're trying to see this factor at baseline, how does it influence hypertension 10 years later, you usually exclude people who have hypertension at baseline?

02:58Because you want to see the development of hypertension. In this case, we're looking at insomnia symptoms. But insomnia is one of those conditions that's not necessarily static. It resolves, right? So you can have insomnia and then a few years later not have insomnia or you can not have insomnia now and develop insomnia.

03:22And so what we did is we broke our down our participants into two groups. the people who had no insomnia at baseline and at three years follow-up participants who had insomnia at baseline but not at 3 years followup. So they were in the healthful sleep improving sleep and then the other group was all those women who had insomnia at baseline and at three years and no insomnia at baseline but insomnia at three years.

03:55So they were the persistent insomnia progressing towards poor sleep group. And we found that the women who had a diet that was more closely aligned to the Mediterranean diet. But we also looked at uh an American type of diet profile called the DASH diet.

04:13The dietary approaches to stop hypertension. Women who had a dietary profile closer to those two types of diets, healthful diets were less likely to have hypertension uh insomnia at three years. And the DASH diet is what?

DASH Diet Explained

04:30Dietary approaches to stop hypert hypertension was developed to uh reduce prevent hypertension, reduce blood pressure in people by increasing intakes of fruits and vegetables, nuts and seeds, consuming low-fat dairy, more plant-based types of uh diet and and can be has been tested in a low salt or regular salt profile.

04:53How did those work out? I'm just curious. Do you recall if the low salt high salt um condition? There is salt sensitivity. So there are some people who are very sensitive to salt and so having a reduced salt diet will really improve their blood pressure, others not so much.

05:06But the DASH diet regardless of its salt content did better than the equivalent non-dash which would be your average you know American diet whatever that is. Yeah. Higher insaturated fat and sugars and which seems to be changing now because of the GLPS.

05:22I I feel like that's, you

GLP-1s & Changing Appetites

05:25know, uh maybe that's a skewed perspective, but I feel like the the typical American diet is it might not be changing so much in content, but in volume it seems like people are eating less. Certainly the snack food companies, from what I understand, are struggling.

05:37Alcohol companies, that's a different issue, but there certainly have uh sales are way way down, but it just seems like people's appetites are down. Well, GLP1s will do that, right? Yeah. Yeah. And we were talking about this the other day here.

05:51Uh how many Americans have tried a GLP? The estimates are anywhere from like one in seven. Some people say it's it's more which is pretty incredible. Yeah, it's pretty high. But this is interesting. So how people eat impacts their sleep. I'm sure the listeners and I also am thinking okay but people who are eating a Mediterranean diet, right?

06:12olive oils, fish, you know, fruits, vegetables, they are probably more apt to walk more, exercise more, socialize more, all the how do you separate out the variables in a study like that? Uh well, so in population based studies, we adjust for a bunch of coariants, right?

06:28We have all these questionnaires that uh that are given out to people asking them about their race, occupation, sociodemographic uh socioeconomic status and then we adjust we adjust for um different illnesses that they may have, depression, physical activity level.

06:46Um so we try to take all this in into consideration. Obviously we there's always unmeasured factors that you can't control for social interactions like you um you mentioned it's usually not captured very well.

Controlled vs Self-Selected Diets

07:04It's not something that we uh we can adjust for. But one thing that we did in my lab uh going back to that original study was to look at uh how diet influenced sleep at night in the participants in our inpatient study. So we took the 9-hour time in bed opportunity phase only that one.

07:29[snorts] In the 4-hour time in bed opportunity, participants were very efficient. There was not much variability in sleep duration in that phase. They slept as much as they could in that 4-hour opportunity. But in the 9 hours, there was variability there.

07:42Some people got more or less. So we wanted to see if food intake was related to their sleep at night. that study we had polynography assessments of sleep every single night like I mentioned we had uh controlled diet initially and then we let them self- select their food intakes so we took a very systematic approach to evaluating how diet could influence sleep in that study we said first of all was the diet that they chose different than the diet that we gave them first step right it was so they ate almost 450 calories more.

08:21They ate 33% more saturated fat. Uh a little less protein, I believe, a little more carbohydrates. Not much, but it it was different. So, like, okay. So, so there's difference between the diets. Okay. Now, was [snorts] their sleep at night different when they were eating the diet that we fed them compared to what they self- selected?

08:45And it they it was different. It wasn't different in terms of duration, but it was different in time it took them to fall asleep, which was over 70% longer to fall asleep when they self- selected their diet. And their slowwave sleep, so deep sleep was shorter.

09:04I think it was about 23 20% shorter uh when they self- selected their diet compared to what we had given them. Was timing of food intake impacted? Because when I think of uh what impacts what reduces um slowwave deep sleep, it's eating too close to bedtime.

09:22Mhm. So, we did not take that into consideration in that study. We didn't uh we didn't look at that. We had their their food intake profile and didn't specifically look in that phase when's when was their last eating period. But it could have been different than in the controlled feeding condition because in the controlled feeding condition they had set meals at specific times, but they all went to bed at 10 p.m.

09:48Then the

How Nutrients Affect Sleep Stages

09:50other question was, okay, what was it that they ate that day that impacted how they slept that night? And we found that higher intakes of fiber were associated with more deep sleep, higher intakes of saturated fat, less deep sleep, and then more refined carbohydrates, simple sugars, more arousals.

10:13So when we talk about arousals in the context of polyynography, it doesn't necessarily mean full-on waking up or awakening. It really means going from a deeper to lighter stage of sleep. So you may still be asleep throughout the night, but you're not getting deep slowwave sleep, REN sleep as much as you would uh otherwise.

10:37Do you create a buffer between your last bite of food and the time you go to sleep? You personally? Me personally, yes.

Best Time To Stop Eating

10:45Is it an hour, 2 hours, 3 hours? I personally like to eat my last meal at least 3 hours before going to bed. And I know there's variability there. Different people have different uh tolerance. You mentioned right before that uh you know some people may be later chronotypes but what we know is that eating earlier is better overall for cardio metabolic health.

11:10Eating earlier is better. Me personally I feel I feel better by eating earlier. If I eat too close to bedtime I I get hot. Right. [laughter] Yeah. It's a It's a thermic effect of food. We want to be cooling off when we go to sleep. Exactly.

11:26Exactly. [music]