Some questions about intermittent fasting - help?
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As to breaking the fast - who cares? What is the downside of breaking the fast?
because while some people use IF only to restrict calories, others are interested in the added health benefits that might occur after fasting for 12 hrs...
"The metabolic switch occurs when glycogen stores in the liver are depleted, generally 12 h after the cessation of food intake, and adipose tissue lipolysis increases to produce more fatty acids and glycerol."
"In those regimens that do not involve true fasting (see Table 1), the “metabolic switch” mechanism would not engage and presumably the mechanism of action is simply decreased caloric intake. Other potential mechanisms of health benefits from fasting are under study currently. These include the potential impact of intermittent fasting on inflammation, reactive oxygen species, blood pressure, and cholesterol levels [13,16], some of whose changes may occur simply due to weight loss but that may potentially also be impacted through mechanisms that are independent of weight change."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6521152/Erythritol is a pentose-phosphate pathway metabolite and associated with adiposity gain
in young adults
Author(s): Katie C. Hootman, Jean-Pierre Trezzi, Lisa Kraemer, Lindsay S. Burwell,
Xiangyi Dong, Kristin A. Guertin, Christian Jaeger, Patrick J. Stover, Karsten Hiller
and Patricia A. Cassano
Source: Proceedings of the National Academy of Sciences of the United States of
America , Vol. 114, No. 21 (May 23, 2017), pp. E4233-E4240
Published by: National Academy of Sciences
Stable URL: https://www.jstor.org/stable/10.2307/26483334
That study does not say what you seem to be implying. First, the study that you are pointing to has nothing to do with consumption of erythritol - it has to with the body producing erythritol as a byproduct of glucose metabolism. Second, it was an observational study that did not measure the amount of erythritol that the study participants consumed - the only thing that they did was take a blood sample to measure the levels of serum erythritol (as a metabolite) at the start and end of the semester and then measure the differences in the levels.
But to your original point, yes, some people do have increased appetite as a result of consuming artificial sweeteners, but the number of people who do is very small compared to the number of people who regularly consume the artificial sweeteners.
As to breaking the fast - who cares? What is the downside of breaking the fast?
0 -
As to breaking the fast - who cares? What is the downside of breaking the fast?
because while some people use IF only to restrict calories, others are interested in the added health benefits that occur after fasting for 12 hrs...
"The metabolic switch occurs when glycogen stores in the liver are depleted, generally 12 h after the cessation of food intake, and adipose tissue lipolysis increases to produce more fatty acids and glycerol."
"In those regimens that do not involve true fasting (see Table 1), the “metabolic switch” mechanism would not engage and presumably the mechanism of action is simply decreased caloric intake. Other potential mechanisms of health benefits from fasting are under study currently. These include the potential impact of intermittent fasting on inflammation, reactive oxygen species, blood pressure, and cholesterol levels [13,16], some of whose changes may occur simply due to weight loss but that may potentially also be impacted through mechanisms that are independent of weight change."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6521152/Erythritol is a pentose-phosphate pathway metabolite and associated with adiposity gain
in young adults
Author(s): Katie C. Hootman, Jean-Pierre Trezzi, Lisa Kraemer, Lindsay S. Burwell,
Xiangyi Dong, Kristin A. Guertin, Christian Jaeger, Patrick J. Stover, Karsten Hiller
and Patricia A. Cassano
Source: Proceedings of the National Academy of Sciences of the United States of
America , Vol. 114, No. 21 (May 23, 2017), pp. E4233-E4240
Published by: National Academy of Sciences
Stable URL: https://www.jstor.org/stable/10.2307/26483334
That study does not say what you seem to be implying. First, the study that you are pointing to has nothing to do with consumption of erythritol - it has to with the body producing erythritol as a byproduct of glucose metabolism. Second, it was an observational study that did not measure the amount of erythritol that the study participants consumed - the only thing that they did was take a blood sample to measure the levels of serum erythritol (as a metabolite) at the start and end of the semester and then measure the differences in the levels.
But to your original point, yes, some people do have increased appetite as a result of consuming artificial sweeteners, but the number of people who do is very small compared to the number of people who regularly consume the artificial sweeteners.
As to breaking the fast - who cares? What is the downside of breaking the fast?
I think the issue is that there isn't much research that triggering this "metabolic switch" is necessary or required for weight management or good health in general. So even it it was true that a packet of Equal in your coffee or a splash of milk in your tea stopped it from happening, what's the downside?3 -
Rannoch3908 wrote: »So is this not true from Harvard?
IF makes intuitive sense. The food we eat is broken down by enzymes in our gut and eventually ends up as molecules in our bloodstream. Carbohydrates, particularly sugars and refined grains (think white flours and rice), are quickly broken down into sugar, which our cells use for energy. If our cells don’t use it all, we store it in our fat cells as, well, fat. But sugar can only enter our cells with insulin, a hormone made in the pancreas. Insulin brings sugar into the fat cells and keeps it there.
Between meals, as long as we don’t snack, our insulin levels will go down and our fat cells can then release their stored sugar, to be used as energy. We lose weight if we let our insulin levels go down. The entire idea of IF is to allow the insulin levels to go down far enough and for long enough that we burn off our fat.
The thing is, anyone that's been doing IF for a long time and tried both IF and non IF knows that IF doesn't really have an impact on weight loss, separate from caloric intake.
I've been doing IF for almost two years. During that time, though, I've had periods when I wasn't doing IF, like a week here, a few weeks there, and last summer I took about 6 weeks off. Also I had a blood glucose scare and did serious low carb for a while, so I've got some n=1 data on that too (my BG has since dropped back below 100 and now I'm back on carbs, because they taste good).
Anyway, I think it's possible that IF has a tiny, tiny, TINY impact on the rate of weight loss, in a positive way, but we're talking like "a little". So instead of losing 6 lbs in a month, maybe I lost 6.25 lbs in an IF month. Could just be margin of error. Could be real but nearly immaterial. And low carb made absolutely no difference at all in my weight loss. My spreadsheet could just as well not include macros for all the difference carbs make to my weight loss, which is to say "none".
I don't think anyone who's done IF or Keto for a long time has experienced something different. These techniques do not impact weight loss except - and this is the important part - insofar as they help you control your calories.
And so, the question becomes, since, in the real world, people on IF or low carb schemes lose weight almost precisely in accordance with their calories in and out, then what is all that mumbo jumbo about insulin and fat stores and cells releasing this and hormones doing that even mean? Pretty much nothing.2 -
That's interesting! I've been looking into why so many people regain weight back after a calorie restrictive diet, and one study showed, among other things, that the glucose and leptin levels were lower( after the diet) in those that didn't regain. And so that's one reason I'm interested in IF having the potential for lowering insulin and glucose levels. I do agree that there's not enough research yet. My specialty is anthropology not nutrition, though, so take what I think about it with a grain of salt!:)Rannoch3908 wrote: »So is this not true from Harvard?
IF makes intuitive sense. The food we eat is broken down by enzymes in our gut and eventually ends up as molecules in our bloodstream. Carbohydrates, particularly sugars and refined grains (think white flours and rice), are quickly broken down into sugar, which our cells use for energy. If our cells don’t use it all, we store it in our fat cells as, well, fat. But sugar can only enter our cells with insulin, a hormone made in the pancreas. Insulin brings sugar into the fat cells and keeps it there.
Between meals, as long as we don’t snack, our insulin levels will go down and our fat cells can then release their stored sugar, to be used as energy. We lose weight if we let our insulin levels go down. The entire idea of IF is to allow the insulin levels to go down far enough and for long enough that we burn off our fat.
The thing is, anyone that's been doing IF for a long time and tried both IF and non IF knows that IF doesn't really have an impact on weight loss, separate from caloric intake.
I've been doing IF for almost two years. During that time, though, I've had periods when I wasn't doing IF, like a week here, a few weeks there, and last summer I took about 6 weeks off. Also I had a blood glucose scare and did serious low carb for a while, so I've got some n=1 data on that too (my BG has since dropped back below 100 and now I'm back on carbs, because they taste good).
Anyway, I think it's possible that IF has a tiny, tiny, TINY impact on the rate of weight loss, in a positive way, but we're talking like "a little". So instead of losing 6 lbs in a month, maybe I lost 6.25 lbs in an IF month. Could just be margin of error. Could be real but nearly immaterial. And low carb made absolutely no difference at all in my weight loss. My spreadsheet could just as well not include macros for all the difference carbs make to my weight loss, which is to say "none".
I don't think anyone who's done IF or Keto for a long time has experienced something different. These techniques do not impact weight loss except - and this is the important part - insofar as they help you control your calories.
And so, the question becomes, since, in the real world, people on IF or low carb schemes lose weight almost precisely in accordance with their calories in and out, then what is all that mumbo jumbo about insulin and fat stores and cells releasing this and hormones doing that even mean? Pretty much nothing.janejellyroll wrote: »As to breaking the fast - who cares? What is the downside of breaking the fast?
because while some people use IF only to restrict calories, others are interested in the added health benefits that occur after fasting for 12 hrs...
"The metabolic switch occurs when glycogen stores in the liver are depleted, generally 12 h after the cessation of food intake, and adipose tissue lipolysis increases to produce more fatty acids and glycerol."
"In those regimens that do not involve true fasting (see Table 1), the “metabolic switch” mechanism would not engage and presumably the mechanism of action is simply decreased caloric intake. Other potential mechanisms of health benefits from fasting are under study currently. These include the potential impact of intermittent fasting on inflammation, reactive oxygen species, blood pressure, and cholesterol levels [13,16], some of whose changes may occur simply due to weight loss but that may potentially also be impacted through mechanisms that are independent of weight change."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6521152/Erythritol is a pentose-phosphate pathway metabolite and associated with adiposity gain
in young adults
Author(s): Katie C. Hootman, Jean-Pierre Trezzi, Lisa Kraemer, Lindsay S. Burwell,
Xiangyi Dong, Kristin A. Guertin, Christian Jaeger, Patrick J. Stover, Karsten Hiller
and Patricia A. Cassano
Source: Proceedings of the National Academy of Sciences of the United States of
America , Vol. 114, No. 21 (May 23, 2017), pp. E4233-E4240
Published by: National Academy of Sciences
Stable URL: https://www.jstor.org/stable/10.2307/26483334
That study does not say what you seem to be implying. First, the study that you are pointing to has nothing to do with consumption of erythritol - it has to with the body producing erythritol as a byproduct of glucose metabolism. Second, it was an observational study that did not measure the amount of erythritol that the study participants consumed - the only thing that they did was take a blood sample to measure the levels of serum erythritol (as a metabolite) at the start and end of the semester and then measure the differences in the levels.
But to your original point, yes, some people do have increased appetite as a result of consuming artificial sweeteners, but the number of people who do is very small compared to the number of people who regularly consume the artificial sweeteners.
As to breaking the fast - who cares? What is the downside of breaking the fast?
I think the issue is that there isn't much research that triggering this "metabolic switch" is necessary or required for weight management or good health in general. So even it it was true that a packet of Equal in your coffee or a splash of milk in your tea stopped it from happening, what's the downside?
1 -
As to breaking the fast - who cares? What is the downside of breaking the fast?
because while some people use IF only to restrict calories, others are interested in the added health benefits that might occur after fasting for 12 hrs...
"The metabolic switch occurs when glycogen stores in the liver are depleted, generally 12 h after the cessation of food intake, and adipose tissue lipolysis increases to produce more fatty acids and glycerol."
"In those regimens that do not involve true fasting (see Table 1), the “metabolic switch” mechanism would not engage and presumably the mechanism of action is simply decreased caloric intake. Other potential mechanisms of health benefits from fasting are under study currently. These include the potential impact of intermittent fasting on inflammation, reactive oxygen species, blood pressure, and cholesterol levels [13,16], some of whose changes may occur simply due to weight loss but that may potentially also be impacted through mechanisms that are independent of weight change."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6521152/
First off, your body continually switches between fat burning and sugar burning throughout the day - it's not an either/or situation.
Of the listed benefits (in your paragraph and else where in the paper), the only one fasting has been proven as a benefit in humans is for decreasing insulin resistance and that can also be ameliorated thru losing weight (thru any means). As far as I have been able to find in the literature, there is not a single other benefit to IF that has been demonstrated in humans.5 -
Rannoch3908 wrote: »So is this not true from Harvard?
IF makes intuitive sense. The food we eat is broken down by enzymes in our gut and eventually ends up as molecules in our bloodstream. Carbohydrates, particularly sugars and refined grains (think white flours and rice), are quickly broken down into sugar, which our cells use for energy. If our cells don’t use it all, we store it in our fat cells as, well, fat. But sugar can only enter our cells with insulin, a hormone made in the pancreas. Insulin brings sugar into the fat cells and keeps it there.
Between meals, as long as we don’t snack, our insulin levels will go down and our fat cells can then release their stored sugar, to be used as energy. We lose weight if we let our insulin levels go down. The entire idea of IF is to allow the insulin levels to go down far enough and for long enough that we burn off our fat.
Fat cells release their stored sugar....
Huh?
Also - muscle and liver also store glycogen/sugar.
That's not using it as energy, he misses that usage.
They are literally just stored.
Now from there they are released and used as energy when the body needs it.
So after eating while insulin elevated - carbs you've eaten stored as glycogen in liver and muscles, where it's been used since last time topped off, so could be a lot stored there.
Used as immediate energy needs right then since fat isn't being released.
If after a while blood sugar still elevated then energy heavy conversion to fat to be stored in fat cells - that's the one to read up on as to how often does that actually get to that point?
Allow insulin to go down far enough .... - author sounds like they copied this from somewhere, or used exact phrases used elsewhere.
3 things said incorrectly in 2 simple paragraphs - that says - nope, that's enough.
Next you'll find something in there that says sugar is burned first until it's gone no fat is burned.5 -
Rannoch3908 wrote: »So is this not true from Harvard?
IF makes intuitive sense. The food we eat is broken down by enzymes in our gut and eventually ends up as molecules in our bloodstream. Carbohydrates, particularly sugars and refined grains (think white flours and rice), are quickly broken down into sugar, which our cells use for energy. If our cells don’t use it all, we store it in our fat cells as, well, fat. But sugar can only enter our cells with insulin, a hormone made in the pancreas. Insulin brings sugar into the fat cells and keeps it there.
Between meals, as long as we don’t snack, our insulin levels will go down and our fat cells can then release their stored sugar, to be used as energy. We lose weight if we let our insulin levels go down. The entire idea of IF is to allow the insulin levels to go down far enough and for long enough that we burn off our fat.
We lose weight by being in an energy deficit, period, end of story...
5 -
I have used IF as a part of my overall plan and it has helped. I do mine a bit differently than most. I do not keep to a regimented schedule as it impacts the family. Rather I start my fast after dinner whenever that may be then eat nothing for the next 16 to 18 hours. It may not be as productive as other methods but still helps1
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I have used IF as a part of my overall plan and it has helped. I do mine a bit differently than most. I do not keep to a regimented schedule as it impacts the family. Rather I start my fast after dinner whenever that may be then eat nothing for the next 16 to 18 hours. It may not be as productive as other methods but still helps
That's the "kitchen is closed" strategy. As in "after dinner, the kitchen is closed." For me, that's been 99 % of the benefit of IF right there. In fact I really don't care about the morning part anymore.3
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