hey guys back with another educational

video and this week we’re gonna do

something a little bit different we’re

not reviewing a study or or a group of

studies or anything like that we’re

talking about a product this week now I

know this product has been popping up in

a lot of your social media feeds because

you guys send it to me and you must

think it’s BS castella you’re like hey

do you bunk this first off I never like

to like set out to just debunk something

I like to make sure that like whatever

I’m looking at you know does it have

validity or not before I just go

attacking because that’s a very

dangerous mindset to get into and the

products actually been popping up in my

social media feed as well it’s called

lumen the claims I saw initially were

that basically find out what fuel your

body is using right now and it can it’s

kind of triggering triggering word for

me but heck your metabolism to know

whether or not you’re burning carbs or

fats well I figured pretty early on it

must be using an R er or respite or E

exchange ratio R er refers to the amount

of co2 produced by metabolism versus how

much oxygen is being used by metabolism

basically the way you do this is you

breathe into something and it measures

like what gases are being expelled from

your body versus what’s in the room and

essentially it can tell you based on

that ratio whether or not you’re

predominantly burning carbohydrates or

fats or a mix of both so an re R of 1

for example means you’re almost

exclusively burning carbohydrate and re

are of 0.7 is nearly exclusively fat and

anything in between there is a mix I did

see a video and apparently there’s an

app that goes along with this I don’t

know if the device has been validated

but if it’s been validated re R is a

completely reasonable measure it does

measure what fuel you’re utilizing now

before you go out and buy one wait till

the end of the video because I’m going

to explain why fuel being utilized is

not the same thing as fat loss or fat

gain the app is also giving you

nutritional and workout instruction

based on what your AR AR is and some of

the screens I saw and I don’t know how

the backend works or anything like that

so I can only make opinions based off

what I’ve seen but some of the screens I

saw were for example you’re doing great

looks like you’re burning a lot of fat

have a high carb day today and then

when hey looks like you’re burning too

many carbs let’s have a low carb day

today and that sort of thing which hey

that seems reasonable but you have to

understand fuel being oxidized is not

the same thing as fat loss so for

example just because you’re burning a

lot of fat doesn’t mean you’re losing a

lot of fat fat loss or gain is

determined by the equation of fat

balance equals fat stored minus fat

burned or fat oxidized now if you eating

really high fat very low carb diet you

will burn a lot of fat you also store a

lot of fat because the body doesn’t

really store carbohydrate as fat there’s

been several studies on overfeeding

showing that basically of the fat you

store approximately 98% of it to 99% of

it is from dietary fat only one to two

percent of the fat you store in your fat

cells is from carbohydrate so carbs

aren’t really stored as fat it’s mostly

dietary fat stored as fat so if you eat

a lot of dietary fat and low

carbohydrate you’ll burn a lot of

dietary fat but you’ll also store a lot

of dietary fat so whether or not you

lose fat or gain fat will be determined

by your energy balance not how much fat

you’re burning now if you’re eating a

high carb diet for example you won’t

burn very much fat but you also won’t

store very much fat

once again the balance of fat loss or

fat gain will be determined by your

energy balance which is how many

calories are you taking in vs. how many

you’re expending this device isn’t

telling you how many calories you’re

expending it’s just telling you what

your body’s preferred fuel source is and

that can also be deceiving in of itself

for example you cannot change your diet

at all but if you start doing really

really high-intensity exercise you’re

RER will go up you’ll be using much more

carbohydrate but that doesn’t mean that

you’re not losing fat it just means that

that fuel at that particular time is

predominantly carbohydrate now what

we’ve seen in exercise studies is that

if you burn a lot of carbohydrate during

your workout you end up burning more fat

throughout the rest of the day if you

end up burning a lot of fat during your

workout you burn more

bow hydrate throughout the rest of the

day okay your body balance is this very

well so the problem that I could foresee

is if this app is using how much fat

you’re burning is kind of being

indicative of whether or not you’re

losing fat and telling you hey you need

to have a high carb day today because

you’ve been burning a lot of fat you’re

doing a great job well if you then have

a high carb day guess what’s gonna

happen to your RER it’s gonna go up and

now it’s gonna tell you you’re burning a

lot of carbs so guess what’s gonna

happen the next day it’s gonna tell you

to have a low carb day and you’re gonna

oscillate back and forth like that and

it’s giving no consideration to what

your energy balance is now I don’t know

if there’s like a calorie tracker in the

app or anything like that that could be

there that could be something but if

it’s only operating off of RER it’s not

really giving you useable data in so far

as body composition now maybe you’re an

athlete I would argue then that there’s

still limited data than it provides but

maybe you just really care about what

your fuel selection is I personally

don’t because again at the end of the

day it’s gonna boil down to energy

balance and how many calories you’re

consuming versus your energy expenditure

based on your BMR and meet TEF and your

exercise energy expenditure so I think

the tool itself may be reliable I think

making determinations on your diet based

on the fuel that your body is using at

the time it’s probably very unreliable

in terms of trying to get yourself

consistent results that’s my take on it

personally I’m not gonna buy it and I’m

not gonna recommend my clients buy it

and I don’t really know what data that’s

really helpful for body composition it’s

going to provide but if you really care

about whether or not you’re burning

carbohydrate or oxidizing fat in

regardless of whether or not you’re

gaining or losing fat then maybe it’s

helpful alright guys hope you enjoyed

this video if you enjoy the video give

it a thumbs up subscribe to the channel

and I’ll catch you next week