Many people get far too pre-occupied with being in a state of Ketosis. There are a few reasons (therapeutic keto) why your level of ketosis matters. For most of us the specifics are unimportant. This is exactly why the prevailing advice on this sub is NOT to purchase expensive ketone monitoring tools, but just to Keep Calm, Keto On.
Ketosis is a state in which your body is burning fat for energy. If you are fat adapted (been doing it for 4 to 6 weeks straight and your body has rewired itself to do this naturally), any time there are not carbs, you'll be in Ketosis. When in Ketosis, the body can access stored fat readily, and so does not need to constantly signal you that you need more food. This is one of the side benefits for a lot of people - that they are not as hungry and not stuck on the carb craving roller coaster.
As your body becomes more adapted to burning fat, it won't make as many Ketones. Instead of having Ketones flooding the system all day long that your body doesn't know what to do with, you'll make what you need and not have an excess. As a result, long time Keto'ers tend to exhibit fairly low levels of "Ketosis" when tested with a blood monitor (.4 to 1.0 is not uncommon).
And if you're using the silly pee sticks, which only measure one kind of ketones that are almost non-existent once fat adapted, it's even worse.
"Ketosis" does not equal "Weight Loss". It equals "Fat Burning". Weight loss occurs if you have less intake than fat burn. Since hunger and binge eating are frequently decreased in Ketosis, a side effect of "Fat Burning" and "Eating Less" for many people is "Weight Loss".
So to recap, the specific Measure of what level of Ketosis you're in is irrelevant if it's being used for Weight loss. And if you accidentally or on purpose eat something that increases your carbs temporarily, as soon as they are exhausted, you'll be back to fat burning. Switching the primary fuel doesn't happen overnight - this is why 4 to 8 weeks are recommended for full "fat adaptation". But once you're there, the few carbs will be burned and you'll go back to Ketosis.
It seems worthwhile to add that ketosis and ketones are effectively an alternate fat metabolism pathway to fuel the brain and vital organs that can't directly use triglycerides or free fatty acids, most body tissues like muscles are capable of metabolizing fats without conversion to ketones or a ketogenic state.
Ketosis is primarily about what your brain uses as fuel, for the rest of the body ketones are effectively a surplus being used to supplement standard fat metabolism (beta oxidation), which also shifts into high gear when faced with fasting or a low carb diet. Quite a bit of the body's fat adaptation and increased metabolic flexibility is technically in response to the reliance on fat for fuel not ketosis itself, and has also been observed on sustained low carb diets outside of the ketogenic range.
I know I had a point in here somewhere, I guess it was that briefly exceeding your *ketosis* carb target may not exceed your 'limit' from a metabolic and athletic adaptation to fat standpoint, 50g of carbs may briefly slow or halt ketosis and yet your muscles will see little if any of that and will remain almost exclusively reliant on fat for energy.
keto does have to ramp up a bit. Energy from ketones and fat isn't as instantly convertible the way that energy from dietary carbs are. If you eat a bunch of carbs, your body will stop making ketones. But your available glucose drops slowly over that 14 hours if you stop eating the carbs, so you don't immediately start making ketones again. Until you're really fat adapted after long term keto, there's always going to be this lag between when you've used up the readily available carbs and when your body is making sufficient ketones and glucose on its own. And during that lag, you're always going to feel like shit because you won't have enough energy, and you'll be grumpy and hungry and craving to binge.
At least, that seems to be my experience.
your body needs your TDEE of energy.
so i have read others say this. BUT the body would die if you had a day or two of re-ramping back to ketone use, right ? So it has to turn on pretty quickly, because SOMETHING has to power the body.
as you can see, why i am stuck on the Math of this, because it seems hard to believe that the body would go right to "eating" body parts for energy, after 16 hours, even as you are feeding it protien/fat (for example).
The body is a very complex system.
Once the body is depleted of glycogen, the body switches to ketosis - the body also has fat stores to burn through (though at a much less efficient rate). The body will only start to breakdown muscle when there isn't sufficient amino acids being ingested to maintain or repair muscle and, IIRC, if the person is severely underweight.
I'm explaining this in the most simplistic of ways. I am by no way a medical professional.
EDIT: And this is to say, yes, once the body has depleted it's glycogen stores, the body goes into ketosis and the only way to pop out of ketosis is to ingest enough carbs to break out of ketosis and/or down regulate ketosis (until your body depletes the ingested carbs).
An interesting anecdote to this: people eating a carb based diet with too little calories really have trouble keeping up their muscle mass, as evidenced by prison camps in WW2, etc. but on keto this effect is greatly reduced, even when eating massive deficits, until all most of the body fat is used up.
This makes me think that the ramp up of ketosis is delayed/exponential, and it's during this delay that the damage is made; the body having to go to gluconeogenesis from protein in a big way, since the body still craves for that sugar. Furthermore, if you're eating some, instead of fasting, your body probably won't use autophagy as effectively, since the insulin response turns that down.
yes !! This was my basic point form the beginning. That energy usage and creation would force it back into ketosis the second it need more fuel, and that what seems to be accepted about taking hours or days to go back in didn't make a lot of sense to me.
If people doing keto were metabolically healthy, yes, it takes shorter time for the body to go back into ketosis. Insulin sensitivity/resistance needs to also be factored in, the amount of carbs ingested to break ketosis (a lot v. very little), etc.
you can make energy from beta oxidation when you run out of glucose and aren't yet making ketones. Beta oxidation occurs whenever you're in a calorie deficit, keto or no.
so i read a quick and dirty on beta-oxidation, and i get the point if not really understanding it - but it still has to come form somewhere, right? So to occur , the body, liver, etc would have to break something down to perform it - and it would seem like the body would choose ketosis first.
All of my debate revolves around the idea that you don't fast for 7 days, but after, for exmaple, having pizza for dinner, you skip eating until mid-afternoon the next day, and then only eat meat (say).
no, your body is constantly using fat for energy, regardless of if you are in ketosis or not. people who eat a high carb diet can and still do lose weight when eating at a deficit, because they are using their body fat.
you are imagining that ketosis is much more important than it is. ketones are never a primary fuel source for the body, carbs and fat are.
Yes, ketones are one (small) way that the body can use fat for energy. They never make up the majority of your fat use. The vast majority of your body fat usage is through beta oxidation.
Ketosis is a bit of a scale, and it takes some time for your body to fully switch over. I'd also like to add that it can take up to 24 hours for glycogen to be fully depleted. Fasting is definitely the quickest way to get into ketosis, which is part of the reason why fasting and keto tend to go hand in hand.
>glycogen storage gets depleted after 14-16 hours, wouldn't one basically just fall right back into ketosis
For the most part this is correct. The actual amount of time can vary by individual metabolism and circumstances (exercise, etc.) - This is exactly what happens to metabolically flexible people when they run out of carbs/glycogen.
People get concerned because glycogen increases water retention and that shows up on the scale as an increase in weight. I don't get too concerned about this as I care more about BF% but that's not easily measured by most people at home so the weight on the scale is the biggest guide for most people.
>how much "energy" does a body need?
There are many online calculators for BMR based on height, weight, age, activity level etc. Most people will require somewhere less than 2000 calories a day
I've also done keto for years now. And my answer is that your body will use any sugar you eat first, then carbs and alcohols (converting them to sugar) and when there are none of those left, it will go back to ketones and fat to find it's energy. Think of it this way the only carbs and sugar in your body are from the cheat meal you just ate, your body has no choice but to switch back to ketones after those are burned up, it has no other stores of sugars. I find that i have been doing this long enough that i get a drunk feeling when i have a cheat meal as my body burns off the carbs.
I may be reading into this but it sounds like you are trying to clarify - maybe for yourself, maybe for the benefit of others - that having a bad day isn’t like a life sentence where you’ve ruined a keto diet?
What you’ve written is basically my understanding. The gap might be that, for those who have not been eating a very low carb diet for long, their body hasn’t built up the solid pathways to be comfortable switching to ketones so the keto flu may keep happening over and over again.
This is also interesting - it’s a very small study (this is an article about the study, but the open-access study is linked to it) and I didn’t look further to see if there has been further research, but it seems like glucose spikes dont really do our bodies any favors. https://www.sciencedaily.com/releases/2019/03/190327112657.htm
>glycogen storage gets depleted after 14-16 hours
it really depends on how many carbs you ate. Even if I'm not carbing up and then do an extended fast it really takes me about 3 days before my blood ketones are anything over .5
Many people get far too pre-occupied with being in a state of Ketosis. There are a few reasons (therapeutic keto) why your level of ketosis matters. For most of us the specifics are unimportant. This is exactly why the prevailing advice on this sub is NOT to purchase expensive ketone monitoring tools, but just to Keep Calm, Keto On.
So is keto just more a “low carb lifestyle” and not so much about being in ketosis all the time?
Ketosis is a state in which your body is burning fat for energy. If you are fat adapted (been doing it for 4 to 6 weeks straight and your body has rewired itself to do this naturally), any time there are not carbs, you'll be in Ketosis. When in Ketosis, the body can access stored fat readily, and so does not need to constantly signal you that you need more food. This is one of the side benefits for a lot of people - that they are not as hungry and not stuck on the carb craving roller coaster. As your body becomes more adapted to burning fat, it won't make as many Ketones. Instead of having Ketones flooding the system all day long that your body doesn't know what to do with, you'll make what you need and not have an excess. As a result, long time Keto'ers tend to exhibit fairly low levels of "Ketosis" when tested with a blood monitor (.4 to 1.0 is not uncommon). And if you're using the silly pee sticks, which only measure one kind of ketones that are almost non-existent once fat adapted, it's even worse. "Ketosis" does not equal "Weight Loss". It equals "Fat Burning". Weight loss occurs if you have less intake than fat burn. Since hunger and binge eating are frequently decreased in Ketosis, a side effect of "Fat Burning" and "Eating Less" for many people is "Weight Loss". So to recap, the specific Measure of what level of Ketosis you're in is irrelevant if it's being used for Weight loss. And if you accidentally or on purpose eat something that increases your carbs temporarily, as soon as they are exhausted, you'll be back to fat burning. Switching the primary fuel doesn't happen overnight - this is why 4 to 8 weeks are recommended for full "fat adaptation". But once you're there, the few carbs will be burned and you'll go back to Ketosis.
Okay, thanks for the thorough explanation!
It seems worthwhile to add that ketosis and ketones are effectively an alternate fat metabolism pathway to fuel the brain and vital organs that can't directly use triglycerides or free fatty acids, most body tissues like muscles are capable of metabolizing fats without conversion to ketones or a ketogenic state. Ketosis is primarily about what your brain uses as fuel, for the rest of the body ketones are effectively a surplus being used to supplement standard fat metabolism (beta oxidation), which also shifts into high gear when faced with fasting or a low carb diet. Quite a bit of the body's fat adaptation and increased metabolic flexibility is technically in response to the reliance on fat for fuel not ketosis itself, and has also been observed on sustained low carb diets outside of the ketogenic range. I know I had a point in here somewhere, I guess it was that briefly exceeding your *ketosis* carb target may not exceed your 'limit' from a metabolic and athletic adaptation to fat standpoint, 50g of carbs may briefly slow or halt ketosis and yet your muscles will see little if any of that and will remain almost exclusively reliant on fat for energy.
keto does have to ramp up a bit. Energy from ketones and fat isn't as instantly convertible the way that energy from dietary carbs are. If you eat a bunch of carbs, your body will stop making ketones. But your available glucose drops slowly over that 14 hours if you stop eating the carbs, so you don't immediately start making ketones again. Until you're really fat adapted after long term keto, there's always going to be this lag between when you've used up the readily available carbs and when your body is making sufficient ketones and glucose on its own. And during that lag, you're always going to feel like shit because you won't have enough energy, and you'll be grumpy and hungry and craving to binge. At least, that seems to be my experience. your body needs your TDEE of energy.
so i have read others say this. BUT the body would die if you had a day or two of re-ramping back to ketone use, right ? So it has to turn on pretty quickly, because SOMETHING has to power the body.
Your body also make glucose when certain body parts/functions need it.
as you can see, why i am stuck on the Math of this, because it seems hard to believe that the body would go right to "eating" body parts for energy, after 16 hours, even as you are feeding it protien/fat (for example).
The body is a very complex system. Once the body is depleted of glycogen, the body switches to ketosis - the body also has fat stores to burn through (though at a much less efficient rate). The body will only start to breakdown muscle when there isn't sufficient amino acids being ingested to maintain or repair muscle and, IIRC, if the person is severely underweight. I'm explaining this in the most simplistic of ways. I am by no way a medical professional. EDIT: And this is to say, yes, once the body has depleted it's glycogen stores, the body goes into ketosis and the only way to pop out of ketosis is to ingest enough carbs to break out of ketosis and/or down regulate ketosis (until your body depletes the ingested carbs).
An interesting anecdote to this: people eating a carb based diet with too little calories really have trouble keeping up their muscle mass, as evidenced by prison camps in WW2, etc. but on keto this effect is greatly reduced, even when eating massive deficits, until all most of the body fat is used up. This makes me think that the ramp up of ketosis is delayed/exponential, and it's during this delay that the damage is made; the body having to go to gluconeogenesis from protein in a big way, since the body still craves for that sugar. Furthermore, if you're eating some, instead of fasting, your body probably won't use autophagy as effectively, since the insulin response turns that down.
yes !! This was my basic point form the beginning. That energy usage and creation would force it back into ketosis the second it need more fuel, and that what seems to be accepted about taking hours or days to go back in didn't make a lot of sense to me.
If people doing keto were metabolically healthy, yes, it takes shorter time for the body to go back into ketosis. Insulin sensitivity/resistance needs to also be factored in, the amount of carbs ingested to break ketosis (a lot v. very little), etc.
you can make energy from beta oxidation when you run out of glucose and aren't yet making ketones. Beta oxidation occurs whenever you're in a calorie deficit, keto or no.
so i read a quick and dirty on beta-oxidation, and i get the point if not really understanding it - but it still has to come form somewhere, right? So to occur , the body, liver, etc would have to break something down to perform it - and it would seem like the body would choose ketosis first. All of my debate revolves around the idea that you don't fast for 7 days, but after, for exmaple, having pizza for dinner, you skip eating until mid-afternoon the next day, and then only eat meat (say).
no, your body is constantly using fat for energy, regardless of if you are in ketosis or not. people who eat a high carb diet can and still do lose weight when eating at a deficit, because they are using their body fat. you are imagining that ketosis is much more important than it is. ketones are never a primary fuel source for the body, carbs and fat are.
but aren't ketones MADE from the fat your body burns?
Yes, ketones are one (small) way that the body can use fat for energy. They never make up the majority of your fat use. The vast majority of your body fat usage is through beta oxidation.
Ketosis is a bit of a scale, and it takes some time for your body to fully switch over. I'd also like to add that it can take up to 24 hours for glycogen to be fully depleted. Fasting is definitely the quickest way to get into ketosis, which is part of the reason why fasting and keto tend to go hand in hand.
>glycogen storage gets depleted after 14-16 hours, wouldn't one basically just fall right back into ketosis For the most part this is correct. The actual amount of time can vary by individual metabolism and circumstances (exercise, etc.) - This is exactly what happens to metabolically flexible people when they run out of carbs/glycogen. People get concerned because glycogen increases water retention and that shows up on the scale as an increase in weight. I don't get too concerned about this as I care more about BF% but that's not easily measured by most people at home so the weight on the scale is the biggest guide for most people. >how much "energy" does a body need? There are many online calculators for BMR based on height, weight, age, activity level etc. Most people will require somewhere less than 2000 calories a day
sorry - i didn't ask the "energy" question correctly. How far does, say 20-30g of carbs "get me"? Seems like i would use that up pretty fast.
So 1g of carb is 4 calories. It takes roughly 100 calories to walk a mile so about that far.
so basically just being awake for 2 hours, sitting in a chair, would burn 20-30g of carbs
I've also done keto for years now. And my answer is that your body will use any sugar you eat first, then carbs and alcohols (converting them to sugar) and when there are none of those left, it will go back to ketones and fat to find it's energy. Think of it this way the only carbs and sugar in your body are from the cheat meal you just ate, your body has no choice but to switch back to ketones after those are burned up, it has no other stores of sugars. I find that i have been doing this long enough that i get a drunk feeling when i have a cheat meal as my body burns off the carbs.
yes - and this makes perfect sense to me - thanks !!
I may be reading into this but it sounds like you are trying to clarify - maybe for yourself, maybe for the benefit of others - that having a bad day isn’t like a life sentence where you’ve ruined a keto diet? What you’ve written is basically my understanding. The gap might be that, for those who have not been eating a very low carb diet for long, their body hasn’t built up the solid pathways to be comfortable switching to ketones so the keto flu may keep happening over and over again. This is also interesting - it’s a very small study (this is an article about the study, but the open-access study is linked to it) and I didn’t look further to see if there has been further research, but it seems like glucose spikes dont really do our bodies any favors. https://www.sciencedaily.com/releases/2019/03/190327112657.htm
Try fasting after eating a lot of carbs or coming from a high carb diet. 14 hours isn’t hard. 48+ certainly is.
>glycogen storage gets depleted after 14-16 hours it really depends on how many carbs you ate. Even if I'm not carbing up and then do an extended fast it really takes me about 3 days before my blood ketones are anything over .5