Intermittent Fasting - How Many Carbs A Day To Survive?

intermittent fasting how many carbs a day do you need to survive we hear all

the time how important carbohydrates are how you will get energy from

carbohydrates how your brain can't function without the glucose from

carbohydrates but if that is true then how much do we actually have to have and

where do they come from when we're fasting today we're going to dispel the

myths we're going to give you the facts and before we're done you're going to

understand exactly how it works so that next time that someone tries to tell you

that your brain will run out of fuel if you go on a fast then you can relax

because you know exactly how it works coming right up

hi I'm dr. Ekberg I'm a holistic doctor and a former Olympic decathlete and if

you want to truly master health by understanding how the body really works

make sure you subscribe and hit that notification bell so that you don't miss

anything while all of the data that I'm going to share with you is documented

and very easily verified a lot of the conclusions and a lot of the

correlations that I'm sharing I have never seen in print or in video anywhere

else so I believe this is the first time that these correlations have been

presented this way lots of people know that glucose is a necessary fuel for the

brain so people are wondering where do we get it when we're fasting cuz we're

not taking in any glucose and when we run out of glycogen stores we can still

fast so how does that work when I set out to do this video and I did some

research I had some ideas of what I thought I would find but I was

absolutely blown away I was awestruck by how brilliant how elegant everything

about our bodies everything about our physiology is designed and I know I can

be a little bit of a geek but if you're even half the geek I am I think that

you'll be blown away as well so I think you'll like this one first I want to

dispel some myths because we've been told that carbs are the preferred fuel

so many places you look online I say oh well of course carbs are with preferred

fuel and it's just something that's been repeated so many times that a lot of

people just think that's how it is but the fact is the truth is that your body

is amazingly well adapted at using whatever fuel you give it okay it's good

with some variety over time because only fat or only protein or only carbohydrate

only works so long so it's good to know how to mix it up a bit but to say that

we have to have carbohydrate it's just plain wrong our ancestors probably

had some carbohydrates in the summer during growing season but they were

probably without carbohydrates almost entirely or mostly without carbohydrates

for long periods of the year so it's not a preferred fuel it is a fuel the reason

some people think it's preferred is that the body will burn it first and why is

that and it won't necessarily burn it first it will just take care of it first

because blood sugar is toxic to the brain that's why diabetics get these

devastating side effects they get blindness they get kidney failure they

get neuropathy with amputations because really high blood sugar destroys tissue

so it's essential for the body to bring it down that's why it handles it first

but it doesn't mean it's a preferred fuel and we'll talk about what happens

to it that it doesn't actually burn it it just takes care of it it converts it

first into glycogen and then to fat myth number two carbs are essential we're

told that because the brain has to have them they're essential because they

provide energy they're essential so essential is something that you cannot

live without it is something that your body cannot manufacture and if you don't

add it into your diet then you will die two examples are essential amino acids

amino acids are the building blocks of proteins and if you don't add them in

your diet on a regular basis you will die that's what essential mean and there

are essential amino acids there are essential fatty acids such as linoleic

acid and linoleic acid your body can't make them so they have to be added and

the diet you die without them that's what essential means but there are no

essential carbohydrates and if I have missed something I urge you to send me

the link send me the information and tell me which the essential

carbohydrates are I would just love to know myth number three the brain can

only use glucose for fuel so it is true that glucose is necessary for the brain

it is true that the brain is more limited in which fuels it can use

because of something called the blood-brain barrier proteins and long

fatty acids can't make it across so the brain is more limited but it is not true

that glucose is the only fuel when carbs are in limited supply and when the body

becomes fat adapted then a byproduct of fat metabolism is called ketones so when

we're in ketosis from a ketogenic diet or when we are fasting so we're eating

no carbohydrates then we'll burn more fat will become fat adapted and as much

as 75% of the fuel of the energy of the brain is derived from ketones so yes

glucose is necessary for the brain but it can do really really well on a mix of

about 25 percent glucose and 75 percent ketones and as a matter of fact lots of

research are showing that the brain behaves and performs a whole lot better

with a mix of ketones and glucose than on glucose alone so that was just

clearing up a few myths and you can verify those anywhere online it is

straight out of textbooks of physiology from Wikipedia there is no discussion

there is no confusion on those now how much carbohydrate does the brain need we

said it has to have some the brain uses 20% of all your calories it's a very

very active organ it's only 2% of your body weight but it uses 20%

your calories so let's assume round numbers that you're using 2,000 calories

a day for your whole body 20% of that would be 400 calories of energy that

your brain needs every day and then we know that only 25% of that has to be

glucose which makes the daily requirements a hundred calories and 1

gram of glucose is 4 calories so when we divide that out it becomes 25 grams so

that is the number when people tell you that we have to have carbohydrates that

is true because the brain needs about 25 grams of carbohydrate was not true is

that you have to add them in the diet and that you need them on a regular

basis you must have eaten food at some point in your life that the body could

convert to carbohydrates or were carbohydrates but you do not once you

have a body you do not need to add them on a regular basis and we're gonna

explain exactly why and how that works just to clarify because someone's going

to bring this up there is one other tissue that can only use glucose and

that's red blood cells they don't have a nucleus they don't have the mitochondria

that can use oxygen so the only fuel source for red blood cells is to take a

glucose molecule and split it down the middle in something called glycolysis

which means to break glucose and in the process they get a little bit of energy

and they produce lactic acid the beauty of that though is that the lactic acid

can be recycled so the red blood cells aren't actually using up any precious

resources they're just redistributing a little bit because the liver can turn

this right back into glucose because the liver can

utilize oxygen and it can sort of use that oxygen on behalf of the red blood

cells and convert that lactic acid back and the liver makes the glucose so these

25 grams are gonna come from the process called gluconeogenesis when we don't eat

carbohydrates when we don't add them from the outside on a daily basis such

as a longer fast then gluconeogenesis meaning making glucose from scratch

making glucose from something that wasn't glucose and it's possible to do

that from amino acids and from lactic acid also known as lactate and from

something called glycerol so these are the main components that exist in the

body that when we don't eat carbs the body can turn them into glucose so that

we can construct we can manufacture those 25 grams first we have to look at

where they came from in the first place because we said that they they exist in

the body when we're fasting in some shape or form so we had to eat them at

some point and I'm going to use carbohydrates because they're the ones

who raised blood sugar carbohydrates get broken down in your digestive tract they

get absorbed into the bloodstream they become blood glucose insulin is the

hormone that opens the door into the cell and guides the glucose into the

cell now the cell has three choices the cell can use this glucose it can oxidize

the glucose with oxygen use oxygen and the mitochondria to turn it into energy

and on average if you're at rest or at very low activity you will be using

about eighty to a hundred calories per hour anything more that you ate that

gets into the bloodstream is going to have to be stored

and it will be stored either as glycogen or as fat if you eat a meal of a

thousand calories and there's some lot of carbs in there then that meal is

going to pass through the bloodstream the blood glucose in the next couple of

hours so at the end of those two hours you will have used 160 to 200 calories

the other 800 or so calories have to be stored and you can

store in the form of glycogen so glycogen is a storage form the muscles

and the liver can put away sugar in the form of glycogen and store it and you

can store about a maximum of 1500 people are little different if you're an

athlete if you do carb loading you can up this number a little bit but it is

approximately 1,500 anything more than that has to be turned into fat and that

is where the fat on your body comes from it is not from the fat that you eat it

is storage form insulin is a storage hormone insulin stores for future use

they they are reserves now next to really make these points clear I'm gonna

get just a little bit technical but don't worry it's gonna be simplified and

you're gonna get the picture you're gonna see why I'm doing this

carbohydrates the basic unit of a carbohydrate is called glucose and that

is a ring the molecule is shaped as a hexagonal as a ring with six corners and

it has six carbons it has a carbon molecule in each corner of that hexagon

the other version of storage is fat and when the body stores something as fat it

doesn't store it as pure fat it stores it at something called triglycerides and

this is not an exact conversion but just to give you an idea that triglyceride

it has three fatty acids and it has a backbone of glycerol and the glycerol is

a molecule with three carbons so the way I want to think about this is that a

glycerol molecule is basically half a glucose molecule it's not an exact

conversion but the body can go through some steps were in the end it becomes

essentially the same the body doesn't store pure fat it puts half a molecule

of sugar of carbon that can be converted into glucose via gluconeogenesis with

every triglyceride molecule so here comes a little bit of math don't worry

about the numbers I believe my math is correct and I have

not accounted for if there is a tenth of a percent of the triglyceride that's

converted differently and so forth we're going to assume that the carbons in

glycerol are worth about the same as a carbon in glucose they're really really

close so if you take glycerol and you take a really really large number of

those molecules called a mole that's basically roughly a 1 with 23 zeroes

it's like a billion billion billion billion or so molecules then those

molecules of glycerol are gonna weigh 92 grams and if we burn those at four

calories per gram we're going to get 368 calories out of that very large number

of glycerol but for every glycerol molecule there are three fatty acids

there are three fat molecules and these come in varying lengths but I try to

find the answer of how long they are on average but I couldn't find that so a

typical fatty acid molecule is 16 carbons long so that's that not the

number we're going to use so if we take three of those fatty acids they're gonna

weigh for the same really large number of molecules they're gonna weigh 769

grams and this is pure fat now so the fat is converted at 9 calories per gram

so we get six thousand nine hundred and twenty-four calories from one mole of

triglyceride molecules from the fat portion so if we add this all up one

mole of triglycerides will give us 860 that will wait 861 grams and give us

seven thousand 292 calories so now we get to the cool part why does the body

store things as fat why is that such a good way of storing energy what is that

survival value well it can only store things as triglycerides as fat or as

glycogen but the glycogen also which is pure carbohydrate at four calories per

gram also is going to bind water at about a two to one ratio so every gram

of glycogen is going to bind to grams of water and therefore glycogen will only

give us 605 calories per pound whereas triglycerides the combination of

fat and glycerin will give us three thousand eight hundred and forty

calories that means fat is six point three times more efficient and storing

energy and if you think a hundred pounds of fat is a lot then think about what

630 pounds of glycogen would feel like to carry around and while we can only

store about 1500 calories of glycogen we can store almost unlimited amounts of

in the form of triglycerides so someone who's very lean like myself are still

gonna have about a hundred thousand calories stored as fat or triglycerides

and someone who is extremely obese someone who weighs five six hundred

pounds they could have upwards of a million

calories store so there's no limit on how much energy we can store as fat but

the cat that glycogen run runs out very very quickly all right so now we're

getting to the part that got me goose bumps when I was doing this research so

I had a drum roll but that this is so awesome so let's say that we're fasting

and we're not adding any protein or any fat or any carbohydrate we're doing a

water fast we can drink some tea and that usual stuff and let's say that we

are burning about 2,000 calories a day because the body still has to maintain

all its regular functions we still have to move we still have to think and and

do all that stuff we still have to repair stuff so we're burning about

2,000 calories but it all comes from triglycerides and if we do that we're

burning 236 grams of body fat consisting of triglycerides in a day that's about

0.5 2 pounds so if we go back and we realize that one mole of triglycerides

weighed 861 grams that's almost 2 pounds and then one pound of triglyceride is

going to give us 48 point 5 grams of glycerol or glycerin that can be turned

into carbohydrates once we do the math on that then the fats that were burning

on a fast will give us exactly 25 point 3 grams of carbohydrate of things that

can turn into blood glucose for the brain which

is the exact same number that the brain needed based on the 25% glucose that it

needs to run that's not supplied by ketones so I was always wondering where

does the 75 percent comes come from how come that the balance just happens to be

that but the body is so beautifully designed that it learned that it can use

25% glucose and 75% ketones and it needs 25 grams of fat because it can get

another 25 from the stored body fat and then I was thinking well why doesn't the

body why does it store things as triglycerides why is it that we don't

just store the fat the way it is and again it's so brilliant it just fits

right into all the math that we've been done that particular molecule is the way

of giving the body the 25 grams of carbs that it needs my mind was blown I don't

know about yours maybe I'm a little geekier than you are but it didn't end

quite there when we did a little more math and we figured out how many percent

of the calories does the glycerol represents well these 368 calories

compared to the fat is exactly five percent so your body stores five percent

carbohydrate stuff that can turn into carbohydrate with the fat because it

knows it's going to need it when we burn body fat when we have no other food it

knows that's exactly the amount that it's going to need to fuel the brain and

then it occurred to me I had seen this 5 percent someplace before if you look at

the keto recommendations the macros of fat protein and carbohydrate

that are recommended to put you in ketosis the 5% carbohydrate that's

recommended on average is exactly the same 5% that the body gets from burning

pure body fat so when your fat adapted that's exactly the ball the number that

the body needs I hope that managed to blow your way just a little bit okay I

think that stuff is so cool so now we know that we do have to have

carbohydrates we do need glucose but we don't need to eat it so the limit to how

long you can fast is really based on a few different things first how much fat

do you have on the body if you are pretty skinny hundred thousand calories

of fat then you won't last that long I would have a really hard time going for

a month or more I would get super super skinny my body would go through some

not-so-great changes after a month or so but if you have a million calories if

you have 50 70 80 hundred pounds of body fat you could go months and your

metabolism this this picture these ratios would not be stressful to you the

other factor is that you have to get enough minerals and you have to get

enough fluids so I don't recommend people going until your fat burns out

that's not necessarily the best way I'm not saying that zero carbs is the best

way for everybody I'm not saying that you should fast as long as you can but I

want you to understand where the fuel comes from that you're doing something

that is natural to the body and I would suggest that you get your body fat

adapted through a low carb and a keto diet then you start with intermittent

fasting you eat fewer meals a day you go longer between the last meal of the day

and the first meal the next so your body gets used to it it gets fat

adapted and then you get some good books on fasting you learn how this works you

watch some more videos and then you can extend the time but it's important to

know that you are safe you will not ruin your brain you will not run out of fuel

you're not doing something unnatural to your body I hope you found that almost

as fascinating as I did and if you like this video you're gonna love that one

thank you so much for watching and I'll see you next time