How to Use & Interpret a Continuous Glucose Monitor (CGM) | Dr. Casey Means & Dr. Andrew Huberman

the way I think about a glucose monitor first of all I'll say the purpose of the glucose monitor is not to have to game the system and get flat glucose the purpose of the glucose monitor is

curiosity it's to start to understand how it's essentially an MRI for how all of our different dietary and lifestyle strategies are creating this readout of

glucose in our body which I think can be really interesting and in a world where so many cards are stacked against us with diet and lifestyle and where there's a lot of confusion about what's right for us that can be like very

helpful in actually reducing the confusion and the cognitive load of our choices we know that keeping your blood sugar through the course of a lifetime in a low and

healthy range so I don't mean up and down spikes during the day but keeping your blood sugar healthy throughout the course of your lifetime is probably the best thing we can do for longevity

staying insulin sensitive staying out of the diabetic range and so one thing that the glucose monitor does for us is just give us more uh awareness and agency

into like what the trends of our glucose are over time as opposed to a literally one data point snapshot once a year in the doctor's office which is what the

majority of us are used to um I really love the idea that people who are able to wear glucose monitors every now and again maybe once a year maybe more than

once a year they know what their glucose is and so they're never going to walk into a doctor's office and have a bomb dropped on them about pre-diabetes or type two diabetes because you have the

data which is ultimately I hope the world that we can move towards for a lot of biomarkers so you can see Trends over time which I think is very valuable one thing that's fascinating in terms of

early prediction of metabolic disease is that you can see how long it takes your glucose to come down after a meal so in a normal healthy insulin sensitive body even if the glucose goes way up it

should come way down very quickly because the insulin is binding to insulin receptors and the glucose is getting taken up and it it'll lower what is quickly over the course of it should

be down by two hours but from what I've actually seen in our like most insulin sensitive people and also in research that looks at young healthy populations you should basically be spiking and

coming down Spike about 45 minutes and come down hour and a half 90 minutes to two hours but if this is after sorry after last bite after last bite although it's hard to

kind of exactly know but yeah meal is over I would say about 45 minutes to go up to the peak and then start coming down very quickly now if you start to

see that glucose is going up and then trailing very slowly back down to normal maybe taking more than two hours three hours that is going to be one of those

early indicators of potential insulin resistance your body's not clearing the glucose but that's not a metric that we use in standard practice at all and I've

actually seen myself very insulin sensitive my insulin is like 2.5 and you know if I don't sleep and I am stressed and I have been sitting my glucose will

take way longer to come down I have become transiently insulin resistant so I think that's just fascinating to see that so looking what that ultimately the metric that we call that is area under

the curve you want a low area under the curve Au after a glucose Spike so you want a spike and come down quickly that's going to be if you shade the area under the curve it's a small amount if

you go up and then Trail off for two to three hours um that's going to be a lot of shading under that curve and high Au is associated with insulin resistance

basically another thing that you can see um is essentially glycemic variability and glycemic variability GV is a metric of

how spiky your curves are fascina paper out of Michael Schneider's lab uh at Stanford in 2018 called

glucotype reveal new patterns of glucose disregulation totally Landmark study but basically they put continuous glucose monitors on non-diabetic individuals who

by standard criteria of diabetes do not have diabetes and he showed that on a CGM a continuous glucose monitor you have these low variability people that

are pretty much flat throughout the day with little teeny little teeny Rolling Hills after their meals you have moderately spiky people and then you have very spiky people who are going up down up down up down up down when you

correlate those different patterns of glycemic variability in non-diabetic people you find that the spikier they are the worse their biomarkers are metabolically across the board insulin

triglycerides Etc so basically they're they're showing signs through variability of underlying dysfunction that you would never know from a standard test those are the people who I

imagine are probably going to go on to develop diseases and yet based on standard criteria their doctor's telling them that they're fine that they're all the same so he also showed in that study

that non-diabetic individuals when you have a CGM on are going into the diabetic range and the pre-diabetic range a fairly significant amount and we would never know that if you weren't um

if you weren't actually tracking like a movie of the glucose so that's so gemic variability um area under the curve those are two things another really interesting thing you can know from a

CGM is Dawn effect so Dawn effect is basically a term in the literature for how high your glucose Rises right when you wake up in the morning I don't know if you noticed this when you were

wearing a CGM but some people notice that the second they wake up their glucose jumps up 5 10 20 30 points What's Happening Here is that the cortisol Awakening response to actually

get you to wake up and get out of bed that cortisol can cause you to dump a bunch of glucose from your liver because it's basically saying stress hormone cortisol we got to get up we need

glucose to fuel the muscles let's dump a little glucose so it's it's normal but what the research shows is that magnitude of dawn

effect is correlated with insulin resistance so the more the dawn effect you're getting I think it can signal maybe the more stress you're under the more cortisol you have floating around how big your cortisol Awakening response

is but also if you imagine if you're dump all that glucose from your liver and your cells aren't taking it up well because you're insulin resistant that that response that Dawn effect is going to be higher

so I I don't have the numbers right in front of me but typically I I would want to see a dawn effect I think of like less than 10 points so you wake up and you you may very well see a rise this is

absence of any food yet and you do not want to see that going up 20 30 40 points um some people see a little bump again with caffeine in the morning because it's more cortisol and so that's

another thing that standard stuff would never tell you so those are kind of some of the looking at early predictors of metabolic dysfunction more of the fun stuff is like actually just figuring out

like how is food affecting your body and this is where people really enjoy it and like figure out like oh my God this food that I thought was healthy is actually not you know serving me and actually a

lot of people I think who are trying to make healthy choices my boyfriend like he when we started dating he started using levels his healthy snack he worked

in Venice would be to go to Moon Juice and get oh gosh I I don't want to throw Moon Juice onto the bus here but he would get tasty stuff they do but he would get this green juice that was sweetened with dates and it was like $9

and this was like the healthy choice and he saw the second he put on levels that it was causing a huge Spike like 50 60 70 points and then he was

crashing um and he was actually trying to make a good decision so now he's swapped his snacks out for more like you know grass-fed cheese and some flax crackers and maybe like a venison stick

or something like grab and go stuff that isn't spiking as glucose but I think it can help people figure out like which foods are doing what I want them to do and which maybe aren't um and same thing

happened for so many of our members with oatmeal unfortunately oatmeal instant oatmeal is one of the biggest spikers in our data set for breakfast and a lot of people are making that choice because

they think it's heart healthy and and in many people it's actually causing a big glucose Excursion and crash and then in some other people it's not and so it's it's really helping with um what are the

sneaky spikers and then where's the biochemical individuality and there was a phenomenal paper out of um uh um

Israel that from from cell about seven years ago called uh personalized Nutrition By prediction of glycemic responses it made big waves but it basically showed that you and I

could eat the same handful of blueberries and have totally different glycemic responses so the idea of glycemic index as like a certain amount of food with a

certain amount of glucose causes a certain glucose rise it it kind of debunked that and that matters because repeated sustained glycemic variability over time is not good for our health we

want to choose the foods or balance the foods that are going to keep us relatively more stable um so that that's that's very helpful just understanding your personal response to food and then

what are the lifestyle strategies you can use sleeping better walking after meals more resistance training cold plunging breath work that can actually

serve to modulate the food environment to actually reduce the glucose spikes and people find that all of those things can positively impact glucose spikes especially the walks after the meals but

um it's fascinating to see a lot of women especially like menopausal women in our community who find that their glucose patterns are getting worse because estrogen's dropping and that's

going to you know really take a hit on insulin sensitivity they start resistance training glucose comes kind of right back down so because of the monitor they can feel more confident in

the intervention they've chose to do to help with metabolism that kind of creates a virtuous cycle thank you for tuning in to the hubman lab Clips Channel if you enjoyed the clip that you

just viewed please check out the full l length Episode by clicking here