Shireen: In today’s episode, we are in conversation with Dr. Steven K. Malin to explore how your sleep cycle may contribute to a likely increased risk in the development of chronic conditions such as heart disease and type two diabetes. We learn how fat burns differently for early sleepers compared to night owls. And Dr. Malin walks us through how we can rewire our bodies through better sleep, hygiene, exercise, and even general lifestyle modifications. Stay tuned.

Dr. Steven Malin is currently an associate professor of kinesiology and Health at Rutgers University. The primary focus of his clinical translational research is to improve the wellbeing of people through preventing type two diabetes and cardiovascular disease. Dr. Malin views exercise as a drug that when prescribed in an appropriate way, can optimize wellbeing. Welcome Dr. Malin.

Dr. Malin: Thanks for having me.

Shireen: An absolute pleasure. Dr. Malin, can you share a little bit with us of what inspired you to specialize in endocrinology, kinesiology, and work within that and how you see your work contributing to this field?

Dr. Malin: Yeah, I think like a lot of people in the field of kinesiology it’s probably a little cliche to say, but I love sports.

I played sports as a kid. I’ve always been involved in a variety of activities ranging from football to soccer, to baseball and so forth. And as I was growing up, my mother also had type two diabetes. So, I was very familiar with seeing medications in the house, my mom taking them, and really even the hormone insulin taking shots.

So, I just always was intrigued by what’s going on with her? Why is she needing this stuff as a kid? And then as I got older, I think just a natural passion for biochemistry came about and how things like carbohydrates, fats, and proteins that we eat on a daily basis actually impact our body. And really just opened up the whole world of thinking, wow, how are those foods even regulated?

And before I really could learn more, I was just so appreciative of faculty members that I worked with, and hormones just kept coming up and it became a natural link. Then in thinking between biochemistry and these hormones, endocrinology and coupling that with a passion for exercise. It became the best of both worlds.

Here I can actually study how something like exercise impacts these hormones to actually control some of those foods that we’re eating. And the linkage then to type two diabetes and cardiovascular disease just became like shunning spotlight on this situation. And for me, I suppose I hope that the information that we’re seeking can just provide new knowledge to individuals to better their own lives. And also provide information the practitioners to have evidence for what to do and then how they work. And hopefully then what that’ll do is impact the next generation of researchers to try and continue finding new ways to treat and prevent diabetes.

Shireen: I love that. You know, speaking of some of the research that you have done, you did a study back in 2022. Observing the relationship between different chronotypes and metabolic syndrome. Can you explain to our listeners exactly what that is and what that relationship looks like?

Dr. Malin: Sure. Yeah. So chronotype is a really interesting term. A lot of us may not hear it all the time, but we might be more familiar with the idea of being an early bird or a night owl, and a lot of us tend to associate it with that.

I know for me, when I was growing up, sort of everybody functioned later at night. It was just a family activity and learning about it that’s really just what your chronotype is. It’s actually strongly connected to our genetics. So, it’s something that we’re all ingrained with, so to speak, and we tend to have this propensity or this desire, do we like to do things more in the morning or the afternoon or the evening time?

So chronotype is getting at that very idea just when do you prefer to do things. When do you feel your most optimal? And there are different ways to test that. But for us, that became an interesting way to start thinking about things because even when we say someone is living with type two diabetes and we want to improve treatments, that sort of implies maybe there’s one way to go.

But the reality is, if somebody, even with diabetes or pre-diabetes or other risk factors are varying in their chronotype, that might actually imply something about how their body is naturally linked to daily function. And that gets into concepts known as circadian rhythm. And that becomes a really interesting phenomenon tying back to endocrinology. There’s no hormones changed throughout the day. So, we’ve got really intrigued by all this thinking. What does one’s chronotype do to their physiology? How does their body act under different states of life, so to speak. And that really prompted this starting point of different studies we were doing.

Shireen: The research that you did conclude that there is in fact a relationship between chronotypes and their influences on metabolism. Specifically, that people who had an early chronotype Were more likely to convert fat into energy compared to late ones. Can you provide an explanation for why that is the case? And also, you mentioned that that can change. So how does that impact the output as well?

Dr. Malin: Yeah, I mean unfortunately I probably have less of a clear answer to the why this is because to be honest with you we didn’t know what was going to happen. When we look at some of the literature, there’s epidemiological evidence, large cross-sectional studies that will identify people who tend to describe themselves as being more of a laid out or evening type.

It tends to be at higher risk for different cardiovascular disease in disease, such as type two diabetes or high blood pressure. Thinking about that, a real natural question is, well, why is that? And we wondered about that. We’ve seen this evidence out there, but really the detailed understandings of why that is isn’t known.

So, for us, thinking about just how type two diabetes comes about, some people tend to think that our mitochondria or these power grids of the cell that make lots of energy become distorted, something goes wrong in them. That’s one hypothesis and maybe in a way when something goes wrong in the mitochondria that communicates in our cells and actually impairs the ability of insulin to work well, and that then develops something known as insulin resistance.

So just thinking about those facets that tend to be associated with diabetes, we wondered could that be something, could that be something within the chronotypes? Maybe people have later chronotype who have this higher risk. Maybe there’s something different in their metabolism. Maybe there’s something in the way insulin’s working.

So, could we test that? And that’s where we got excited because we were like, yeah, we could actually do this. So that’s what the study really started to get after in thinking about metabolism on a level, it occurs at different times of the day, right? Like our metabolism’s always functioning, but it can change whether we’re rested.

It can change when we’re exercising, and it can even change in response to food. So, what we tried to do is get after all those facets in a way. And what you were describing about fat metabolism differences became quite striking. We saw the patients who described themselves as having a later chronotype compared to an earlier chronotype, right?

So again, that night owl versus morning bird, the later chronotypes metabolism looked different when they were just rested, fasted after overnight. They came into the hospital, and we performed these measurements. They didn’t use as much fat for energy compared to somebody who was a warning bird. And generally, more fat we use for energy is associated with health.

That became one quick observation. Then what we did was actually infuse the hormone insulin into people to study how does insulin actually work on the body. And when we did that, we found that insulin was not as effective in later chronotypes at actually promoting blood glucose to go into the body tissues.

So, we call that glucose uptake. So basically, what we start seeing is this phenomenon under sort of a fasted and fed state now. Since insulin’s so important for controlling, feeding, there are problems in the metabolism apparently. And what became really interesting is we thought, okay, well let’s see what exercise can do.

Is that going to be different? Maybe that’ll rescue some of this difference. And somewhat surprisingly, it was beneficial, but it was not the same benefit we thought. What I mean by that is when people of early chronotype underwent exercise, their body shifted where they were using fat for energy in the rested state, but when they exercised, they switched over and they were using more carbohydrates and fats.

But what was interesting is the later chronotype was using a lot of that carbohydrate earlier because they weren’t using fat. And then when they went to exercise, they increased their metabolism. So, they got benefits. But the amount of switching was not the same. They didn’t use as much fat for energy during exercise, and the carbohydrate levels were different.

So together, when we looked at this, we thought to ourselves, wow, some of this is really mimicking what we would see in some of the classic pathology or relations of diabetes issues. Hearing people with different chronotypes but they don’t have diabetes. So that was somewhat interesting to us to think could this tie back to the understandings of disease risk.

Shireen: And can you discuss the role of physical activity a little bit more in that relationship between the two? What would you even say to someone, or even as people sort of categorize their own cells as they’re listening to this, between being an early or a late one. And how physical activity can really influence their choices there?

Dr. Malin: Yeah, so I like to use an analogy for this. And it’s actually a sponge, so if you could indulge me for a second., I’m sure we’ve all had that experience where we have a sponge in the sink and we use it to wash our dishes, but then we might go away for a few days and we come back, and that sponge is really hard.

It’s like a rock. Right? Okay. I bring that up because in this analogy, the sponges like our skeletal muscle. Now when you’re at home and you first have that sponge out, it’s pretty soft. You put some water on it, it absorbs it. But when you go away for a couple days and it becomes really hard, you put a little bit of water on it, really nothing happens to the sponge, right?

We almost have to douse it with water. We have to really pour it on, cover it up. We got to squeeze the sponge a lot to get that sponge sort of back to that newer state. Okay, well the water in this example now is insulin. Putting this together in a way, what we think is that skeletal muscle is an incredibly important tissue in our body that helps take up glucose and clear it from the blood and it can burn it up for energy, as we were just describing a little bit ago.

Well, if we don’t use that muscle a lot, so say we’re just sitting a lot or we’re busy with work travel, all kinds of things come up in life. But if we sit a lot, that muscle becomes like the sponge. When you go away for a couple days, it becomes more rocklike. It doesn’t respond really well to a little bit of insulin, and this is what gets into that pathology of insulin resistance.

And the muscle basically needs to be contracting. It needs to be moving a lot, needs to be physically inactive. So just like that sponge sitting around for a long time, it becomes like a rock. And that little bit of water that we would put on the sponge initially worked fine, but over time you have to pour more water on.

Well, the body does something similar, pours more insulin into the body and it puts it there in efforts to try and meet the muscle spongy again. But this again is part of that thinking or analogy is of the pathology of diabetes. Now to answer the question of, well, why is physical activity good? How’s it helps?

Well, it’s helping keep the muscle spongy. It’s helping keep it absorbable it, it helps the body not need as much insulin, which really taxes our pancreas, which we all know is very, very important for producing insulin in the body. And if the pancreas becomes exhausted, the thought is it becomes dysfunctional, and it may at some point just stop working as well and not make insulin any longer.

So, in this way, being physically active could directly impact the skeletal muscle, and by impacting muscle, help the pancreas, even though there’s thoughts that exercise can directly help the pancreas too. So, from our standpoint, we think exercise is a wonderful drug this way. Depending on how much movement we do throughout the day, when we do it the types of exercise, the intensity and so forth, these can keep that muscle real spongy and help it take up the glucose in response to insulin.

Shireen: It is hard to change the way that our body is wired especially when it comes to our sleep schedule and sort of making those choices in our day-to-day. As you sort of think through this, how do you advise people to change? Can they change their chronotypes?

Dr. Malin: Yeah. Well, I mean, I will say to start off that I don’t think it’s a good or bad thing, having different chronotypes. Certainly, it’s individual’s preferences and it’s a real big societal issue. If we think about this, this kind of highlights an idea of should we, by recognizing that people may have preferences towards different times of day, should this influence how social policy is? Should we be allowing people more freedoms to decide when to do things versus having, say the classic nine to five work structure?

That’s a very big issue that I can’t answer. I don’t know, but I raised that because I think some of this type of evidence goes towards building an idea that, wait, we might want to think about stuff like that to help people lead healthier lives. You couple that with challenges we have where we are constantly inundated with information.

We may be staying up later and later to watch tv. And how that influences our sleep patterns is also another challenge given that we have so many things that we’re responsible for. So, I think the information we’re getting at is helping provide insight into people why these risks may be different, or why you may be able to do one thing and your friend can do another.

Seemingly despite being similar ages or weights and all of a sudden and now, you’re on a medication and your friend’s not, it’s really frustrating to think why is that? Well, maybe again, some of this comes back to just our chronotype. Unfortunately, to my understandings and knowledge, we can’t really change our chronotype. Because again, I mentioned a part of this is it is genetically linked.

With that said, I think it’s important to recognize everybody changes chronotype essentially over their life. What I mean by that is if we think about children, they sleep a ton. From newborns to as they start becoming toddlers and so forth into adolescence, their sleep pattern changes incredibly.

As you are younger, you sleep a lot. You start sleeping a little bit less into toddler age, you start becoming more alert. Bu they generally are early birds, right? They wake up early, they’re raring to go, and then as they get into teenage years, what happens?

You can’t get them up out of bed. They won’t move out of the bed. But they’re also now starting to stay up later, right? So, when away they’ve shifted from early to evening, and then we rebound again, sort of into the twenties and thirties where we start becoming earlier and earlier to points where maybe as we get into odor age, we’re now more early birds again.

Now I say that because it’s a scale, it’s not necessarily you’re one or the other. You could be on the higher end of an early bird or a lower end, right? I say that all, not to be complex, but to help us think about this as a continuum versus some sort of just one-shop-fit all type of situation.

That said, as we are going throughout life, to your point, what can we do? Well, I think some of this information that we’re learning is the metabolisms are different. The risk factors may indeed be truly different. If that’s the case, at least this evidence would point towards earlier is associated with less risk.

So, what can we do? Well, if we tend to just think about either person, this way we know a good amount of sleep is helpful. Targeting about eight hours is very beneficial. Somewhere between the 9 to 10 is general guidelines. So, in that case, if you are someone who prefers to stay up later and do activities, okay, what can you do to accommodate these factors to help you lead a healthy life?

So, engaging in physical activity is good. We’ve seen in our own data and other people have published that people of later chronotype characterization are not active as much. So just knowing that it could be something to consider trying to get physical activity in throughout the day for the person of later chronotype to help pump up that physical activity level. That could be really beneficial.

The other thing would be eating. Given some of these metabolism differences and we have some data that we’re looking to publish in the upcoming months. Once we finish analysis, we’re learning that people of later chronotype tend to eat more of their calories later in the day than the early chronotype.

And why is that problematic? Because a lot of these hormones that we’re talking about controlling the foods we consume don’t work the same way later in the evening. The body is priming itself to get ready for sleep. But by feeding, you’re kind of saying to it, no, you need to stay awake. And it starts shifting metabolism out of the natural rhythms it wants to do.

So, another thought could be trying to minimize how much late night eating a person’s had the physical activity in eating. Just two behavioral pieces there could help people get to bed a bit earlier. So practically speaking, even if it’s something you like staying up, maybe trying to target, going to bed.

Minimizing blue lights, so looking at your iPhones, your iPads, computers, TVs, and so forth. And maybe start that idea of preparing for sleep. Don’t have to go to sleep. It’s just the idea of starting to calm the body down, get the body into a rhythm or moon, only even with say, melatonin. Getting that ready to really do its job and help you fall asleep.

And then if you can do that, maybe you start seeing that you fall asleep about 15-20 minutes earlier. In turn, if you start maybe even waking up 15-20 minutes earlier, you don’t necessarily want to force it. But that idea of if you’re earlier to bed, you’re earlier to rise by just that time. A couple things can occur.

One, maybe before consuming any food or technology in that way, get a 10–15-minute walk. It doesn’t have to be vigorous. If you can do it outside and weather permits, could be wonderful. These factors of environmental walking have been shown to be helpful. And also, then if there’s sun in that way, the sun becomes an incredibly powerful stimulator to the body.

Light in of itself helps regulate our body clocks and light is thought to be the most potent of three things. With light, diet, and exercise being kind of key clock stimulators. So, if you can think about it in that way, the sunlight, food, and exercise, all help really set our clocks. And by even thinking of just some of these things before bed, as you wake up, they can start regulating the clocks slightly differently so that you’re able to get some of these health benefits we’re describing.

Shireen: And so is it, so if I understand this correctly, is it that our chronotypes are set, it changes as it places with age, we just have to modify our behaviors around it? Or do we have any influence in changing the chronotype to switch from, in this case, late to early?

Dr. Malin: Yeah. My guess would be more the former, the behavior piece. I don’t think it’s something we’re going to change our chronotype per se. Certainly there are people that they might become more earlier birds over time by necessity. I know I have with kids. I sort of need to get up a bit earlier, but also I find that now I engage in activities earlier before they wake up and it allows me more things to do later in the day because I have that time back.

From doing the activities earlier before they’re awake now. Now that’s just an example, that’s not something I would say everybody has to do. But that idea is more, I think it’s an awareness of how your body’s working and what are some then choices we can be making in behaviors to help our body work optimally. And still do as much as we prefer to do with keeping ultimately our mental health in check too.

Shireen: Makes sense. And then is there any other advice that you would provide to individuals who are looking to make lifestyle modifications when they’ve got other responsibilities, different job types, hours, different things influencing their lives? Any other piece of advice that you would like to give to individuals who are trying to adopt new habits or healthier habits? Perhaps move to more of the early chronotype or those types of lifestyle modifications, but just can’t?

Dr. Malin: Sure. No, I certainly appreciate a lot the work constraints become a challenge. Family dynamics can create different obstacles for us to learn how to maneuver. I think some general advice would be for starters, don’t beat yourself up too much.

Sort of appreciate that. Life is challenging and by recognizing some of these obstacles, maybe we can be gentler on ourselves in thinking, how can I still achieve, say, physical activity levels. To use physical activities as an example, we know what kind of general recommendations are to get about 30 minutes of activity a day. Maybe upwards of an hour depending on what your discussions with your doctor are.

But that’s a lot of time, whether it’s 30 minutes to 60 minutes. So, one general piece of advice that I’d love to provide is you don’t actually have to accumulate that all in one setting or one setting. So maybe, maybe loop it together with things. So even if it was a 10-minute walk in the morning, a 10-minute walk at lunch and a 10-minute walk at dinner. You could accumulate some of these very benefits we’re talking about like sunlight exposure or environmental exposures. As well as physical activity amount to keep that muscle spongy.

And that could be a way in which you accumulate that movement. The other thing is maybe even with physical activity, could you engage family in this, make it somewhat of a social event. So, I know for us, we love doing walks after dinner and that’s another thing, even when you do your activity. So, if you could decide should I do it before my meal, after my meal?

Something to consider would be doing these things breaking throughout the day, maybe having some social engagement with family or even friends at work for a lunchtime. But if you could choose with time and flexibility that way after the meal, might be a really nice way to do it. And then general diet would be just moderation.

I wouldn’t view things as good and bad. I think that can be very harmful to people. So, but rather just focus on moderations, allowing yourselves the joy of different facets, but realizing excessive consumption of anything, even too much exercise could be harmful. So, keeping that in mind would be a way to go there.

Shireen: Well, on that note, Dr. Malin, thank you so much for your time. At this point, can you tell the, our listeners how they can connect with you and just learn more about your work?

Dr. Malin: Sure. Yeah. Well, I’m a faculty member at Rutgers, so I’m always happy to communicate through email. I’m also located on Twitter, so I’m happy to dialogue and have direct messaging with people if they like through that. As well as LinkedIn, as some other options for people depending on their preference.

Shireen: Lovely. And we link all of this up in the show notes so folks can connect and carry on the conversation as well as needed. And for our listeners, you know the drill at the end of this episode we pose a question out to you to help understand how this episode impacts your choices. So, head over to our social media, to Facebook, to Instagram and tell us, do you believe you’re an early chronotype or a late chronotype?

Tell us more about that journey, how that has changed for you over time. Again, head over to our Facebook, Instagram, find this particular podcast post and comment below to let us know if you think you’re early or late? And how perhaps you would even adapt if you are late? How would you adapt and make changes in your lifestyle to perhaps make healthier choices for yourself?

So, with that, Dr. Malin, thank you so much again for your time. I really appreciate it.

Dr. Malin: Oh, it’s been my pleasure. Thank you so much for having me again.

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