Hey everyone, welcome to a sneak peek ask me anything or am a episode of the drive podcast. I'm your host Peter Atia at the end of this short episode. I'll explain how you can access the AMA episodes in full along with a ton of other membership benefits. We've created or you can learn more now by going to Peter Atia m.com forward slash subscribe.
So without further delay, here's today's sneak peek of the ask me anything episode. Welcome to another ask me anything episode. This is am a number 17. I'm once again joined by Bob Kaplan and he goes by little Alias on this episode in this episode. We dive pretty deep into body composition. The question actually stemmed from hey, what's the best way to measure body composition but it digressed into
What I think is a very comprehensive discussion of all the different ways that you can measure body fat and there are more than you probably realize along with what it means. What's the difference in subcutaneous? Fat visceral fat? What's the optimal body fat? What are the strategies around improving your health? Is it better to do it through a gain in muscle mass versus a loss in body fat Etc that takes up a heck of a lot of time and it really only leaves time for one other major topic which is one around insulin resistance question basically being hey is insulin.
It's reversible which of course becomes a very long discussion and an opportunity frankly to Showcase a cool little case study, which I do we close this one out with a little bit of a discussion on Topo Chico. So if my recent email on Topo Chico piqued your curiosity including my decision-making around it and what my potential call it substitute agent is that I'm now mixing in with my Topo Chico and alternating with we talk a little bit about that. So without further delay. I hope you enjoy
Am a number 17 is going to be pretty cool am a but I actually thought I was doing it with Bob Kaplan didn't realize I was going to be doing it with Mike Lee you'd what's going on here
donning. The Whalers caps I figured that would be my Alias today. That's usually when I check into hotels because my popularity my celebrity. I usually check in as Mike Lee out.
There's bonus points to anybody listening to this.
Who knows who might glued is but the fact that you and I both immediately. No, well, you know, of course because it's your Alias but I immediately recognized it. I don't know is that sad or
it's impressive I'm wondering how many people will know who the Hartford Whalers are
it's been a while let alone who their goalie was Circa
1984. Yes, and who they are now, they still exist, but they moved and they change their name. Yes indeed.
So what do we have on the agenda Mike or should?
I say Bob for today.
We've got a bunch of questions and I batch them. I think that's as per usual into a few but we've got some stuff on body fat measurements. There's so many out there. What's the best type to use? And do you have to buy your own dexa or can you get away with some of the handheld or the stand up scales that do the will get into that questions around insulin and glucose and insulin resistance and whether you can reverse it, and then we got a bunch of questions around Zone 2.
And then maybe more of a well not a rapid fire, but there are a lot of questions recently about Topo Chico think more people will know when Topo Chico is than the Hartford Whalers and Michael Ute and then a couple other questions, one of the reason weekly emails was about colorectal cancer screening and there are a lot of questions that you could Grill your GI doc or your personal care physician. A lot of people are wondering how do I do that? Delicately without them getting upset? I think we should just dig in from the top which is
Body fat measurements,
I mean I think for context it's worth explaining why one would even care about that. We have a very crude measurement by which we can assess a person's health and it's called wait so you could stand on a scale you can measure a person's weight. And if you juxtapose that with their height, you can calculate something called a body mass index and certainly the body mass index is proportionate to Health in some way shape or form. So we
We generally know that people with a body mass index in the vicinity of 20 to 25 are healthier than people with a body mass index say between 35 and 40 that would be a relatively easy statement to make but it doesn't really tell us a whole heck of a lot between the difference body mass index of 22 versus 26. For example. Do you know your BMI Bob?
I do it's probably I am
you got to be 2728.
Yeah.
That's right. Probably around twenty seven twenty
eight. Yeah, so technically you're you're overweight, aren't you?
I am technically. Yes. I
am you are technically overweight. But as I look at you here on this screen today, you're a staggering specimen of muscle mass.
It helps the my shirts off,
right? Yeah. Yeah, of course, we always topless podcasting family. So how do we capture that? Right? So, how is it that we've got Kaplan?
Over here at a BMI of 27 to 28 who if you just went off an Actuarial Table you'd say. Oh my God, we got to do something about this and I've got patients who have a BMI of 22 and you'd say well fantastic high-five keep it up. But the reality of it is I'd much rather be in your shoes than theirs. What's that difference while obviously a big part of that difference is a muscle mass and your muscle mass is such that your fat free Mass. I guess is a better way to describe it.
Is the dominant part of what you are and so your fat mass is actually very low. So most people now I think by having this discussion have a sense of what we're talking about, which is what percentage body fat. Are you that becomes a much more interesting measurement? So to have a BMI of 27 at you're probably at about 8% body fat is a far healthier place to be and to be at a BMI of 22 with 24 percent body fat the sort of skinny fat phenotype. So will refrain from
I'm digressing into all the nuances of what all that means from a metabolic perspective because I think your question was just how do you do this? And the point here is you have to be able to measure body fat somewhat accurately if you want to get to this next level of thinking so there are lots of ways to do this. Let's go through many of them including ones that are really not necessarily things. I'd recommend for
people think about doing the best one that you probably wouldn't recommend which I think
A ver analysis. That's the most precise
the most precise would be burned calorimetry where you would come bust an individual after they were deceased and by measuring the constitutive amounts of oxygen consumed and CO2 released. Yes, you could get a pretty good guess of their body fat. So shy of that amongst the living magnetic resonance, imaging or MRI would probably produce the most accurate results. I have only had one
If a test in my life done via MRI or two, but it was part of an experiment. I was participating in so this is not something that is a typical indication for MRI. It's usually done in the research setting did we ever do an AMA on how MRI
works? I think Raj was on the podcast. So that's right. That's right. He dug into it. This is probably getting ahead of myself. But one of the things we're going to look at is dexa, which is an x-ray, but people
I can get that to look at their bone mineral density and you can also get body fat. I think a lot of people will go in for the bone mineral density in the software package will spit out and we'll tell them what their body fat percentage is and all that other stuff we can get into that but I'm curious with an MRI when you get into an MRI, if you go in for an MRI, and for another reason, you're not also going to get as part of that package. Oh, by the way, here's your body fat percentage.
Very rarely do people go in for a whole body MRI and even if they did there would be a big software.
Look that would have to look specifically at the protons within fat. It wouldn't be impossible and who knows as time goes on maybe more and more whole body. MRI centers will be spitting out that information quote-unquote for free as the way you described it in other Technologies. But again, when most people go to get an MRI, it's hey my knee my back my this my that were you wouldn't be able to capture all of those data because a whole body MRI is a stupidly time-consuming process unless you're doing it via one of the very very very
If you technologies that can do it in under an hour, most typical commercial grade scanners would take four to six hours to scan the whole body. All that said let's not get into how MRI works. It's the gold standard and the reason it's the gold standard is not just how accurate it is, but frankly that it gives a very very clear picture of where said fat is and this is a point worth mentioning not all fat is created equal. I think for the purpose of this discussion we can put fat into two buckets.
Oh, I really think there's a third we can divide it into cutaneous or subcutaneous fat fat that is beneath the faccia known as visceral fat and I think most people have heard that term because most people probably appreciate that visceral fat is the one you don't want. So it's one thing if you can't see the 6-pack of ABS, but to be clear the inability to see the 6-pack of ABS is really an issue of either too small.
Rectus abdominus muscle group and or too much subcutaneous fat surrounding the rectus abdominus muscles no six-pack equals one of those two things or a combination of them, but it doesn't tell you what's happening beneath the faccia. So you have this corset that is holding you together that is beneath your muscles and it's called fascia and it's inside that fascia that all of your organs exist and that's the place where you don't want to see any fat.
At where this fat typically shows up is around the liver around the kidneys around the spleen around the gut that fat is incredibly associated with metabolic disease. If we were going to track people by some Metric, it wouldn't be BMI. It wouldn't be weight. Frankly. It wouldn't even be body fat percent. It would be total amount of visceral fat in some normalized way if everybody walked around knowing hey, I've got six point three pounds or
Whatever of visceral fat or four point two percent of my body weight is visceral fat and we tracked and manage that holy cow. We'd be in a much better place an MRI allows that so it can very clearly distinguish between these compartments. Also something about MRI. That's fantastic. It's non-invasive produces zero radiation. So you could MRI yourself all day long and you're not going to have that issue. Of course on the flip side of that again. I just think this is a really new
new application for MRI not necessarily practical and obviously from a cost and availability perspective sort of not the way to go.
Do you ever like a ballpark of how much if I wanted to get a number like next to my Barrel son? I want to get an MRI machine how much it might cost
sure for Giggles. So if you wanted to buy so it's about a million bucks a Tesla. So if you said you wanted to slum it and get a 1 Tesla MRI, which would be a super low-end MRI today that would cost you about a million bucks plus hiring someone to run the
I don't think of it as a great investment Bob.
It would be good for dinner parties that when somebody says I have a Tesla and then I'll say well I've got a version of that too as well.
You could say Godfrey Tesla. I've got one point five tests. Yes. There you go. And which I think is The Sweet Spot. Okay. So moving down from MRI another way to measure body fat is actually to use CT scanning. So a CT scan is another type
Type of scanner that you get into just like an MRI they tend to be a heck of a lot faster so you can CT scan the whole body much quicker than you can do. So with an MRI and like the MRI the CT scan does a very good job of showing fat so you very clearly get to see where the fat lies because it's a really really good anatomic study and it basically can show you this is in trouble.
And all this is subcutaneous. And so you again have that tool to kind of quantify not just how much fat the person has but more importantly where that fat resides now here you have less of an issue on the cost side, but the far bigger problem is radiation. And in fact, I would never recommend a whole body CT scan honest. I can't think of a single indication. I would ever consider whole body CT appropriate and it's amazing because years ago, there were all these places pop.
Hang up on street corner saying hey come on in for your whole body CT scan to check if you have cancer, which is the greatest irony of all because God knows how many cancers you were predisposing people to with those things. I suspect in a whole body CT scan would be 50 millisieverts of radiation, which is about the annual allotment that is recognized for a human being and obviously, you don't want to be near the annual allotment on one day but conversely just getting a CT scan of the chest abdomen and pelvis which
Lots of hospitalized patients need it could easily expose you to tend to 20 millisieverts. I'd like to live my life in a sub 10 millisieverts per year environment if
possible. You don't want to be an astronaut Peter.
That's a good question. I mean somebody knows this and of course even though they're wearing unbelievably protective equipment. Do we know how many millisieverts someone would get a year at the
ISS? I think we do. I can look it up. We can include in the show notes. We've got that chart with a different radiation millisieverts.
Yeah,
just standing at sea level for a year. You're probably getting 224 millisieverts. And if you live at elevation, you know, if you're living in some place like Denver, you're probably almost doubling that but you're still well below 10 you want to use CT scans judiciously and there's a time and a place for them but measuring body fat ain't it? Okay you then alluded to something called dexa, which sometimes goes by DX a its dual energy.
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