Metabolic Flexibility and Fasting with Dr Mike T Nelson

Logan Christopher: 00:18 Welcome everyone. Back today with another guest, my friend, Mike T. Nelson. I haven't talked to you in a little bit, but this should be a good catch-up call for us, and diving into some very interesting things. For those of you not familiar with, has a Ph.D. in Exercise Physiology. He has spent some, was it 16 years in college, so you spent?

Dr. Mike T. Nelson: 00:40 Yeah, so I’ve been staying there for a long period of time. Yeah.

Logan: 00:44 Very dedicated to understanding science and everything involved in health and fitness. We will be diving into various different areas and topics around that today. One of the main things you're most well-known for is the idea of metabolic flexibility, but that's not really a mainstream word. Could you define that for people that aren't familiar with it?

Mike: 01:07 Yeah. In fitness we have, all these people would tend to argue about if we just look at the two main fuels, fat versus carbohydrates, kind of which is the best fuel, and there's debates and disputes and all this kind of stuff, which to me doesn't make any sense because it's all like most things you could answer with—Well, it depends, and what context are you talking about?

The metabolic flexibility is—how well does your body use fat and how well does your body use carbohydrates for fuel?

And the third part is—how well and how fast can it switch back and forth between the use of fats and the use of carbohydrates?

And what I like about it is it kind of respects the actual dynamic nature of physiology. Instead of trying to say, Oh, it's a nail, so it must be a hammer, or let's try to use a screw instead and, oh, let's get the screwdriver and try to put that with the nail.

And, yeah, some of those concepts, that once you hear it, you're just kind of like, Oh, that almost makes too much sense. This can't be real.

Logan: 02:12 Right, biology is a lot more complex than many people give it credit and they're always trying to simplify it down, which inevitably leads to dumbing it down and getting to this idea of, Oh, all carbs are bad, right? Something like that or all fat is bad when really there a nuanced understanding is going to be more accurate and actually more help.

Mike: 02:33 Yeah, and that's kind of, and I'm sure you're in the same boat of, I'm always thinking about how do I tell it in a way that it makes sense to people, but not making it so simple now that it's just not even correct. It's like how far can you push that spectrum, but yet still maintain that it's correct? Because I think, in fitness, people go, exactly what you said, a little bit too far and, ooh, this is good and this is bad. And it's hard because just crazy humans want just a simple answer, right? We want to know what is “the” answer. It's probably not quite that simple with physiology.

Logan: 03:11 Right. So, let's talk about it. Take the average standard American eating, the standard American diet. Would you say they don't really have metabolic flexibility, what's going on with their diet and how that is operating for the fuel sources for them?

Mike: 03:26 Yeah, I would say, in general, they're probably more compromised in that area. We do know that if we go to the extreme of that and we look at something that's a pathology like Type 2 diabetes. So, Type 2 diabetes is kind of classically thought of as a problem with carbohydrates, and while that is true to some degree, we see that changes in how your body can process glucose.

Insulin will then go up, so your body says, Hey, we’ve got to get all this glucose out of the bloodstream. We’ve got to stuff it in some form of tissue or transfer it around and make fat out of it, or put it in muscle or stick it in the liver as glycogen. But we can't have this high amount of blood glucose folding around the blood because at some level that becomes toxic.

But most healthy people will never get to that point. They'll have other issues before that. But if you have a Type 2 diabetic, and especially if they're uncontrolled, you can see super high levels of blood glucose.

So, it is true that they do have a problem with the glucose, kind of carbohydrate end of the spectrum for many reasons, but as the disease progresses, what people may not realize is they actually started having issues with the fat end of the spectrum also. So, insulin itself can be thought of as a fuel-selector switch, which I stole from Dr. Jeff Bullock—when we have high amounts of insulin, that actually pushes your body to use more carbohydrates or increase carbohydrate oxidation. When we have lower levels of insulin, that actually pushes the body to use fats primarily as the fuel.

So, if you go back to our Type 2 diabetes friend, they start having issues with glucose, so the body says, Ha, I have a solution. No worries. We'll just keep putting out more insulin, right? We need a bigger signal, a bigger stimulus driver to get that glucose out of the bloodstream and we'll just start jamming it into a bunch of other tissue. If you do blood levels, you'll see over time as the disease progresses, they need more and more insulin to do the same job. But now because that insulin is higher, it actually prevents them or reduces their capacity to use fatty acids as a fuel.

I actually said, if we want to use fats more as a fuel, all things being equal, we actually want insulin to be lower. This high baseline level of insulin is actually preventing them from using fats as well as they could, so our Type 2 diabetes friend actually becomes very metabolically inflexible. They have a hard time at the carbohydrate end of the spectrum. They have a hard time overtime on the fat end of the spectrum, so they're getting kind of crunched from both ends. And the average American is probably somewhere on that spectrum also.

The literature is kind of across the board as to what they have a bigger issue with, but what I've seen just from testing and my view of the literature is that they're kind of coming closer and closer to becoming a Type 2 diabetic. The cutoff for that is kind of a weird arbitrary thing and I think it's better thought of more of a spectrum. Right? I tell clients it's a dimmer switch, not an on and off switch, although for some point we need a line in the sand for a diagnosis that says, Oh, yeah, you hit these markers. Now your blood glucose is 130. You definitely are a diabetic. But the reality is it's much more of a slow progression of kind of slowly turning that dimmer switch in the wrong direction.

Logan: 06:54 Yeah and they call that like syndrome X or metabolic disorder, various names over the years to indicate kind of that spectrum or that pathway that's leading to diabetes, correct?

Mike: 07:06 Yeah, and that's kind of a mess from a research standpoint. If you look back at the original proposer of that, so Gerald Reaven’s original idea was that it's primarily based off glucose and insulin, and over time you basically have to meet these five separate criteria in order to kind of, quote-unquote, “qualify” for that disease. So, by definition, yeah, if you have, I think it's three out of the five markers, yeah, you definitely have a metabolic disorder.

However, when we try to look at it from a research standpoint, we've kind of lumped up a whole bunch of stuff together, right? Which three of the five did you have? What is the main driver? It's like, in my biased opinion, I think from a research standpoint, trying to get to a better answer, it's just made a mess out of everything. But from an actual progression of these things, yep, we, unfortunately, are seen more these people in the U.S. headed in that direction.

Logan: 08:01 And one of the things that seem clear to me and I’d like your thoughts on that, carbohydrates aren't bad, but there does seem to be when you're combining high carbohydrates and high fats as we'll often find in many dessert items, that's where things can be especially problematic.

Mike: 08:17 Yeah. I would say, maybe. I mean, I guess if you would have asked me this five or seven years ago, I probably would’ve said yeah. But looking at the research, I think if you wanted to create the worst possible potential metabolic issue, I would agree that potentially very high fat and very high levels of glucose would be the route to go, and there's a very interesting study that they tried to replicate this and they compared trained individuals to untrained individuals.

And so, at first, they gave them an IV, I think, of around 80 grams of glucose, so kind of what's called an IV glucose tolerance test if you give bolus dose of 80 grams, so pretty big whopping dose of carbohydrates.

And then, they made it even more complicated. They did an infusion of what's called intralipid, which is literally just a large infusion of fat, right into the vessel, so they're purposely bypassing the oral absorption through digestion because they want to try to make this worst-case scenario and just jack up both of these to sky-high levels.

What you found was that if you were a healthy person and had done a fair amount of exercise training, your body could buffer that to a pretty good degree. And if you were untrained or the average kind of person that's attached to their couch cushion, oh boy, you were a metabolic train wreck because now you've got high levels of potentially insulin; you've got all kinds of screwed up dynamics.

To me, the biggest problem is that not only are your mechanics of the hormones and all that kind of stuff, as you just don't have a big enough engine or a big enough sink to dispose any of it, you basically just kind of overrode the whole entire system, where if you're an athlete and you've got a much bigger sink, be it muscle or liver glycogen, different places that you can actually take these things and kind of safely store them away so they don't kind of back up into the system.

The little bit related to that is that there's an old, and it’s probably five years old now, a mouse study, because I thought for a year as I'm like, Hey, we're trying to get athletes leaner. Could we change the sensitivity of insulin in the fat cell, right, in theory, to try to redirect this substrate so it doesn't get stored as body fat?

I did find eventually that they did a knockout study in mice, so they genetically engineered these mice so that they could not traffic, in this case, fat, directly into the fat cell. What they found was that these mice had horrible damage to their liver, their blood levels of triglycerides, so basically the fat backed up in the blood and caused all sorts of just horrible things to happen to the poor little guys.

So, it seems like the bigger sink we have, the better you can take those things and kind of let them flow into the fat cell, into the muscle cell, get them out of the bloodstream so they're not really kind of cause it and as much havoc there. And then, for the body composition standpoint, can we increase that kind of flow for the root both glucose, right, so using muscle glycogen, so replete and deplete, and then also through fat? Can we increase how much fat is being used on the other side, so increase what's called fatty acid oxidation?

So, I tell people, imagine you're going to go take a soak in your bathtub, right? Everyone gets all excited about measuring blood levels of ketones and glucose, and all that kind of stuff, and I think it's interesting and it definitely gives us some data. But just like if I turn the faucet on super high and then for some dumb reason I leave the drain open, if I can get enough water coming into that bathtub fast enough, I can get the level of water in there to rise. Right? So, blood glucose would just be looking at what is the level of water in my bathtub, but it doesn't tell me anything about how much water is going through that system. It's just a snapshot photograph in time.

There's some interesting data on this, too, that if you are basically pulling more energy through the system that everything starts to work a little bit better. Right? So, maybe if I have a really big faucet, I have a high caloric intake, I’d better match that with a high caloric expenditure of some kind, and if I do that, I can buffer a lot of stuff and I'm probably going to be pretty good.

If I do the inverse, even though I keep the water level of the bathtub at the same level, but I dramatically decrease how much is coming in and dramatically decrease how much is going out, I can be okay because I'm kind of in a caloric balance, but to me, it just seems like the system is a lot more fragile, for lack of a better word, at that point.

And, again, that's pretty out there and really pretty highly theoretical, but I think athletes, to answer your question, have pretty good buffering capacity, most of them, which we'll talk about for fat and carbohydrate use, and if you're combining things at a meal, assuming the caloric load is not just astronomically high, you can probably get away with it and do okay. If we take that same idea to an untrained population, we do see that they have a much, much harder time dealing with that.

Logan: 13:28 Yeah, that all makes sense, and to kind of sum it up, what you're saying here is that exercise, some sort of activity, in a sense, trumps diet. Obviously, both are important, but with the activity, you can handle less of a, let's say, quote-unquote, “good diet.”

Mike: 13:47 Yeah, and that’s one thing I've noticed, too, because I've always been fascinated by, so I did some work with some female, pretty high-level college sprinters, some of the top-10-rated sprinters in the U.S.—this was many years ago—and a guy referred me to them, and initially my thought was, Oh my God, these are very high-level collegian athletes and the cool part about track events is everything is timed, so it's like a legitimate thing. You know where you're ranked pretty easily, not as fuzzy a sport like football and things like that.

And my first thought was, Oh man, they're going to be so dialed in. I don't really know what I can do with them as NCAA regulations about supplement recommendations, that kind of stuff. And I'm like, Okay, cool, just go out. Just get four days of a diet log from them. Send it to me. We'll set up all the calls. We’ll get everything going.

I get the dialogues from them and I'm looking at it, and I'm like, What? Fast food for lunch. Fast food for dinner. Calories were super low. No green things other than green-colored M&Ms, you know?

My first thought was, This can’t be right. Were you on holiday? Did you go on vacation? And then, they're like, No, this is what I normally eat. I'm like, Really? And then, I'm left with, holy crap, they're eating, what I would say, very poor-quality food and probably even under-consuming that, but yet their performance is crazy.

So, I always like asking them, nutrition nerds’ hangout, Hey, when you work with elite athletes, how are you amazed at their nutritional intake? And, more often than not, they're like, Oh, this is just horrible. But if you're at that high level, Michael Phelps was a very big example of this, granted I think some of what he did was overblown because I know people that worked with him, but he did take in a massive amount of calories. They take in a massive amount of carbohydrates, things of that nature. But people forget that he was literally swimming most of the day, and you're in the water, which has a thermal load, things of that nature.

So, if you're a freak of the freaks and you're doing a lot of movement, you can probably get away with a lot of stuff. Right? And most you see are younger, earlier in their career, too, and, again, a lot of what we're looking at is more performance, not necessarily healthy either. So, I think if you have enough movement and your movement is good, I think you can get away buffering a lot more things than what people realize and that they get really worried about.

And the second component to that, too, is if you're consuming more calories, right? I remember once years ago, Neal Maddox was one of the top early CrossFit athletes. I went to the gym or he had trained. I was talking to his coaches and staff, and we had posted a picture or maybe he did of him eating donuts in the evening. This was probably six years ago now maybe. Everyone in CrossFit lost their mind like, Oh my God, how is this high-level athlete eat two--

Logan: 16:35 It’s not paleo.

Mike: 16:36 Yeah, it’s not paleo. He’s eating two donuts for dinner. That’s horrible. But when you talk to him, he's like, Yeah, I ate literally about 3,600 calories of vegetables and fruit, and white rice and chicken, and, quote-unquote, “good clean foods,” end quotes, and he's like, I need to get my calories to at least 4,000 to 5,000 calories a day. Otherwise, my performance sucks and I just started losing too much weight. I found if I ate a few donuts and other things like that in the evening, it was very easy for me to keep in the calories that I wanted.

But he's already got probably everything else covered, especially in micro-nutrition and everything else, because his caloric, his needs are so high. If you've got a smaller person who's eating 1,200 calories a day, man, you just don't have a lot of room for a bag of Peanut M&Ms, you know? So, kind of growth factors.

Logan: 17:31 Yeah, it's interesting to think about. I've definitely seen this myself and talked about it that diet and performance, although there's some correlation that really doesn't need to be—I mean, often people end up going both ways—but then with the whole quality, so more micro-nutrient-dense foods, fewer chemicals and toxins, and all kinds of crap, you may not need that when you're young and performing even at the Olympic level, but continuing on that diet long term, we're going to see some negatives from that. So, anyone listening to this, obviously not thinking, Oh, I can just binge on fast food as long as I perform, not quite saying that. There's going to be longer-term chronic effects from such a diet.

Mike: 18:08 Yeah, I agree. I mean, it's a funny thing because I get hate mail from both sides of like, Oh, you said to eat two Pop-Tarts. How dare you tell people to eat Pop-Tarts for breakfast. Don't you know all the carbohydrates and they're processed? And I'm like, I just said if you can't handle eating two Pop-Tarts on occasion, you may have some things related to your metabolism that you need to work on. I didn't say eat two Pop-Tarts for every single meal.

Again, it also depends on what is the context, right? If that's looking at performance and ability to buffer glucose, yeah, it might be a good marker. I mean, I agree that most of the nutritional work I do with people, it's pretty basic—whole foods. Eat vegetables. Try to get as high quality of food as you can get or afford—and then if you're doing that a vast majority of the time and your movement is good, and everything else is on point, your performance, and longevity and health, and all those things are going to be probably pretty good.

And the other experiment that it's hard, I've noticed, with more elite athletes who may not have the greatest nutrition is, subconsciously, they're like, Hey, I'm already performing at this level eating what I’m eating. Why should I bother? And it's almost hard from a psychological standpoint to be like, Maybe you could be 2 percent better, which can be the difference between first place and fifth place where you're at now. We won't know until we run this experiment and try some of these other things to see if it improves.

Sometimes that's a hard sell, not always. I mean, even just the other day, a very elite athlete—I won't say his name or where he works, but he's in baseball—and we did some testing and his mercury levels were pretty crazy high. Again, I'm not trying to be his physician or anything like that. We just thought it was interesting to see.

So, I followed up. I didn't have any dietary logs at that point. I said, “Hey, here's what we found. This is kind of interesting.” His coach was like, Yeah, he eats high amounts of seafood all the time. We've had other tests in the past that have confirmed the same thing and he doesn't want to change.

But in the same athlete, in other aspects, he's very amenable to any type of change. A lot of times I think we forget, especially when we talk more about elite athletes that they're humans, too, and a lot of times are not that different from what we think they would be.

Logan: 20:31 Yeah, absolutely. I want to take this conversation into fasting. That's something I've been doing for a long time and I definitely feel it's one of the biggest keys to building this metabolic flexibility.

Mike: 20:44 I agree.

Logan: 20:45 It's interesting. There's some research, but really I don't feel like there's as much research as should be on this thing and that's probably because it's a free thing. There's no money in that I think that you can't market even supplements for fasting or whatnot, just it's a free thing anyone can do, but it's amazingly powerful.

Mike: 21:00 Yeah, I would agree with that.

Logan: 21:01 How does it play into, how do you see it helping increase our metabolic flexibility?

Mike: 21:07 Yeah, so how I got into fasting is, man, probably almost 12 years ago now, and even back then, I mean, fasting has been around for a long time. You can pull up all sorts of different religious texts of all sorts of mentions of fasting going back thousands of years. It’s not like it’s a new concept per se, but when you've been around in health and fitness for many decades now, a couple of decades, and you see the same trends kind of come and go, and fasting is one of those, other than the crazy detox things, which we'll kind of not consider, fasting for now. It hasn't really ever been that popular up until recently.

How I got into it was, I'm looking at metabolic flexibility and I'm like, Okay, so how do we increase the body's ability to use fat as a fuel? Of course, we can do exercise, but I'm like, But what about on the nutrition side? And the more I kept looking at stuff, the more I'm like, Hmm, I think insulin is probably one of the key hormones. Of course, it's not the only hormone, but one of the keys and insulin is nice because it's under a fair amount of dietary control. Right? Growth hormone, testosterone is very indirectly, very loosely correlated, but insulin is very much directly correlated.

Okay, so if I want to increase the use of fat, I probably want to get the low levels of insulin. Okay, I can not eat some proteins; some proteins are insulinogenic. I can reduce carbohydrates. Fat doesn't really have any insulin release per se, but no one's going to sit around and just do shots of olive oil or something like that, which just seems kind of crazy. I guess they would … now people put all sorts of stuff in their coffee, so it's close, but--

Logan: 22:45 I have drunk it straight from an olive oil bottle, so.

Mike: 22:47 Yeah, I have an occasion, too, when I was bulking once, but, yeah. So, I'm like, Oh, fasting. Oh, so what happens the longer someone's fasting? In healthy individuals, in around 12 to 18-ish hours, maybe a little longer, your basal levels, so your fasting insulin levels get to be the lowest that they're going to get, so it’s this little curve that goes down and then it just kind of flattens out. So, I'm like, Oh.

So, after that point and whatever metabolic stimulus low levels of insulin have, which is, again, debatable, but whatever they are, they would be maximized once that insulin hits that plateau at that low level. So, I started looking at fasting as a way to increase the body's ability to use fat.

Literally, right around that same time, a buddy of mine says, he's like, Hey, I've been doing intermittent fasting. I'm like, really? And at this time, I mean, 12-plus years ago, I was convinced that, oh my God, all your muscles are going to fall off your body because I've been told you needed a certain amount of protein and can cite all the protein studies. And he’s like, No, it's been good. My performance hasn't been dropping. I've been doing about one 24-hour fast per week, which was from actually Brad Pilon, Eat Stop Eat, which was the first one I read on that. He was [crosstalk]--

Logan: 23:59 Oh, it goes back further. Paul Bragg talked about that. That's how I -

Mike: 24:02 Oh, yeah.

Logan: 24:03 - originally got into and I've been doing that now a couple of years. I did it years back. But that's a good cycle.

Mike: 24:09 Yeah, I agree, and you can go back to a lot of the old-timers before that and they would do cycles of fasting and longer periods of not eating, and all sorts of stuff, so, yeah.

So, I was looking at it and he was like, Yeah, it's been good, and eventually I went back and looked at all the literature. I'm like, I should try this. I think there may be something to this. I was doing some training in Arizona and decided to do it. I made it to about noon the next day, so I went from 08:00 p.m. to about noon the next day and ran across the street to a Chinese buffet, which I was there for about two hours. I'm like, Oh, this fasting thing, this is the dumbest idea I've ever heard. I knew it was stupid, right?

And then, I tried it again at another training down in Arizona by a couple of months later. The same thing happened and then I realized, I'm like, Oh, oh, I'm such an idiot, because, at the time when I was awake, I was used to eating every two to three hours. I had been doing that for about four to five years.

And I’m like, Whoa, that would be like someone coming into my gym and being like, Oh, hey, you've never deadlifted before. Let's just put 405 on it and if it doesn't work, I'll just yell at you to try harder. Unless you're like Andy Bolton or something like that when you first started training—I think he pulled 500 or something obscene—it's probably not going to happen. Right? But I can put 95 pounds on with bumpers. I could do 135. I could do 225. I could put it to whatever I want that's scaled to whatever your capacity is.

Then I’m like, Oh, I could do the same thing with fasting and make sure you ever run-in period and it's not so hard.

So, I took six to eight weeks and basically just took one day per week, usually Monday or Tuesday, and then just extended the fast each week by about a couple of hours.

What I found was after about six to eight weeks, it was pretty easy to go 19 to 24 hours and it wasn't too bad. And I started doing it with clients and my first thought was, Oh, it’s going to be a disaster. It's not going to work, and it surprisingly worked pretty good. I found if they had a good run in period. It was fine.

And I tried everything from a 500-calorie meal per day or just protein-only and all sorts of other different modifications, and I think, to my shock, just fasting where you're not consuming anything that has calories for a set period of time was the easiest from even a compliance standpoint, which I think some of it has to do with a little bit of black and white.

I mean, even now, as a recording, it just so happened that today was the day that I ended up doing a longer fast, so the last time I had was dinner last night, probably around 08:30 and I'm going to have dinner probably a little bit after we've finished this call in a couple of hours. But, even then, my wife asked me, “Oh, well, don't you want something to eat now before the podcast?” and I'm like, No, because one thing I did find is I like having a meal and everything already prepared of what I'm going to eat because, once I start eating, there is a tendency to just eat lots of weird things that I wouldn’t normally eat. So, as long as I sit down and have kind of a normal meal that I would have, I find that it works pretty good. Therefore, fasting was a way to increase the kind of the metabolic stimulus to upregulate the body's use of fats.

Logan: 27:22 Yeah, absolutely, because the body goes into a mode where it is using fat just because you're not eating every few hours to replenish the glucose and everything going on. Along with this, I’m curious, have you explored doing longer fasts at all as well?

Mike: 27:38 I have a little bit. I know you can comment on that because I believe you've done some of that.

Logan: 27:43 Yeah.

Mike: 27:43 It's been on my radar for a while. I mean, the longest I've ever done was almost two days and it wasn't too bad. I mean, I broke down 28 hours into it and had a fiber supplement before I went to bed because I was just really stupid hungry, but, surprisingly, the next day, once I woke up, I was pretty good.

I have on my list at some point to do a three-day just water-only fast and possibly a seven-day one. Again, if people have medical conditions, obviously, talk to their physician. All that kind of standard things apply. But I know a fair amount of people who have done it and that seems to be not too bad, and there are different versions of that—I mean, Valter Longo has his FMD version of Fasting Mimicking Diet and a bunch of other stuff in between—but there's not a lot of direct studies on it.

But I think you could make an argument that if your main goal is health and longevity, and maybe reducing your risk of cancer—again, I'm not a cancer researcher—that a three- to seven-day water fast quarterly might be useful. I think that's what Peter Attia does. I know I've talked to Dr. Dom D'Agostino about it, too.

But what was your experience?

Logan: 28:52 Yeah, I've done a few longer, my longest being about seven days and that was kind of a mixed-up plate. There really is all kinds of different fasting from water fasting, like one of the last day I ease back in with bone broth, which was really nice, so you have different types.

And it's interesting because different types are going to highlight certain benefits or downplay other ones. You see those within 24 hours or even less than that, the growth hormone spurting up, but it seems the autophagy, the recycling of the cells, that really kicks in a bit longer. It's probably starting to ramp up, but I think given that longer time period where we may see those cancer benefits. But, as you said, there's not a lot of research on this, just a lot of anecdotal evidence or people pointing to how it may be working. So, it is very fascinating.

But one of the things that's interesting is you do this for a while or you're doing some of the longer ones—it's like training, right?—so, once you've done a seven-day fast, that's the 405-pound deadlift. Then -

Mike: 29:49 Yeah.

Logan: 29:49 - lifting 95 pounds at 24-hour fast feels like nothing, and it's honestly like, oh, I'm not even hungry all day. It's so easy to slip into that, which is a good sign of metabolic flexibility having been built up.

Mike: 30:01 Yeah, I agree with that, and that's why I picked for most clients doing one 19- to 24-hour fast, working them up to that. I don't think most clients need to go much beyond that unless there are really specific things they're working on.

But even just that shorter distance, which is not a seven-day one at all, the biggest thing that was a surprise to me and clients was that, Oh, oh, you mean I don't have to eat? If I'm somewhere like the airport where the food is horrible and I have to pay through the nose at LAX for this horrible food, maybe I just won't eat. Oh, and I can function. I'm going to be okay. I'm not going to be face down on the guy in front of me on the plane, you know?

So, I think just realizing that you can do it, and obviously, you want to build up to that just like anything else, but what I’ve found is that that's kind of a very freeing thought process, too.

Logan: 30:53 Yeah, traveling is one of the extra times when I tend to fast as well for those exact reasons. It's just more convenient and it's like, Okay, what do I want to eat? This fast food or that fast food? There's no good quality food at most airports, so I find that quite useful.

Thank you for listening. We'll be back with Dr. Mike T. Nelson next week to talk about stress, adaptability, and heart-rate variability.