6 ms·

Note that this is probably not what you are thinking (low-carb, very-low carb or even keto diets are good for your healthspan). The lowest quintile in this stu

by fasteo 9y ago

Note that this is probably not what you are thinking (low-carb, very-low carb or even keto diets are good for your healthspan). The lowest quintile in this study were consuming 46,4% of kcal from carbs (that's about 230 gram of carbs for a 2000 kcal total intake). Not even close to low carb by today's standard in the health blogosphere. The authors make this explicit in the discussion section: >>> However, the absence of association between low carbohydrate intake (eg, <50% of energy) and health outcomes does not provide support for very low carbohydrate diets. Importantly, a certain amount of carbohydrate is necessary to meet short-term energy demands during physical activity and so moderate intakes (eg, 50–55% of energy) are likely to be more appropriate than either very high or very low carbohydrate intakes.

internetman55 9y ago
That is about what I have been eating naturally (~150-250g carbs daily, pretty much from oats, potatoes, sweet potatoes, dairy, and 1-2 servings of fruit per day).
smn1234 9y ago
I think the assumption there is very-low carb (as a macro-nutrient, not "healthy" v "unhealthy") can be better if _lower_ carb demonstrates improved outcomes... ?
randallsquared 9y ago
> Importantly, a certain amount of carbohydrate is necessary to meet short-term energy demands during physical activity [...] Why would they make such a claim? Anyone who has done keto and worked out has probably had the experience of doing quite a lot of physical activity while having had no carbohydrate intake at all for half a day before, or more.
- mkrecny 9y ago
  Half a day of carb restriction wouldn't meaningfully deplete glycogen stores.
  - didgeoridoo 9y ago
    I’ve been <20g of carbs per day since February 2016. My athletic performance was impaired for the first 6-8 weeks, but has since increased dramatically. At low circulating insulin levels, most cells in your body can efficiently metabolize fatty acids. For the minority of cells that cannot, your liver converts protein into sugar by a process known as gluconeogenesis. It’s very possible to be a performance athlete and eat very low carb.
  - arkades 9y ago
    80m of exercise is enough to deplete muscle glycogen to as-near-zero as makes no difference. In a sessile starvation state glycogen stops being a meaningful energy source after 2 days, with the majority of it depleted in approximately 8-12 hrs (it's non-linear). Depending on one's baseline physical activity and what they mean by "half a day," sure, glycogen stores can be reasonably depleted. That said, glucogenic amino acids can replenish glucose stores, which can ultimately become glycogen. Glycogen remains low only in the context of low-carb and low-total calories, so what glycogen is replenished is soon exhausted.
  - randallsquared 9y ago
    ...even if you'd already been doing keto on an ongoing basis?
- philfrasty 9y ago
  „no carbohydrate intake at all for half a day before“ no way your body was in ketosis.
  - X86BSD 9y ago
    It takes about a week of < 20g/carbs a day for the body to go into ketosis. This is born out by buying keto strips and testing your urine.
    - rblatz 9y ago
      It takes 3 days for me to hit ketosis at that carb level.
    - gebeeson 9y ago
      I can achieve 'dark purple' on strips in two to three days without drastic dietary or exercise extremes. This is one of my biggest sticking points with articles that make generalizations about body functions. There are always outlying examples and exceptions.
      - corry 9y ago
        You probably already know this, but in case other readers don't, the depth of color on keto sticks is NOT a measure of "how deeply in ketosis" you are. The depth of color indicates how concentrated ketones are in your urine, which is impacted by (1) the amount of ketones your body is producing, and, very importantly, (2) your hydration level (i.e. how diluted your urine is). For newbies, if the stick is pink AT ALL, congrats, you're in ketosis. Don't make the depth of color a big goal.
    - SiddarthaBuddha 9y ago
      this is not true for all people and urine tests are not considered reliable. I can get into ketosis in a single day of fasting
    - fasteo 9y ago
      A little known fact is that you can induce ketosis while eating carbs. The biochemistry here is clear: You get into ketosis when you oversupply acetyl groups to the TCA cycle. Adding MCT (Medium Chain triglycerides) to your diet will do this.
- fasteo 9y ago
  At most, your brain can run with 75% ketones/25% glucose. Other organs (kidneys, red blood cells, cornea) need about 15-25 grams/carb per day. If you do not get glucose from diet, your body will build it (gluconeogenesis). Must see if you want to understand/practice keto right: https://www.youtube.com/user/chrismasterjohn/videos https://www.youtube.com/user/chrismasterjohn/videos
  - GreaterFool 9y ago
    I started a keto diet 2 weeks ago. As far as my research into keto goes eating too much carbs kicks you out of ketosis (duh!) and eating too much protein triggers gluconeogenesis which also kicks you out of ketosis. Which is a shame because I'd be happy to eat fatty steak and fatty pork all the time! Keto guidelines generally say 30g carbs per day and that's what I'm going to stick to (net carbs; I want to eat avocados!). So typical keto diet should work fine with what you say about carb requirement. I don't have any particular desire to go all the way to 0 (or some really low number) and if I have some carb budget left I'm happy to get a latte. Starbucks says grande almond latte has 9g carbs (5g sugars). Perfect to tidy it up to just below 30g/day.
    - have_faith 9y ago
      What was your motivation for starting the keto diet?
      - benballjr 9y ago
        Not sure what this other guy will say, but for the vast majority of people it is for major weight loss, not necessarily lifestyle or belief that it is a "superior" health approach. This is my experience from Reddit's keto and loseit communities anyway.
      - GreaterFool 9y ago
        I've been weightlifting for a while and got fitter and stronger but the progress has been slow so I decided to change things up. I read about keto and the more I read the more awesome it seemed. Since I switched to keto I have an amazing mental clarity. Literally from the moment I open my eyes in the morning I feel lucid (before I'd take me maybe 30 min and maybe a coffee to "wake up"). And I feel lucid all the way until I fall asleep (I don't get tired before falling asleep. Just go to bed, sleep). Nice and steady energy throughout the day. Also, I feel noticeably better overall. My max strength suffered a little bit (keto can take 1-3 months to adjust) but I'm more energetic throughout the day, mind and body.
rhinoceraptor 9y ago
There’s no such thing as necessary carbohydrates. The body is capable of producing all the glucose it needs.
- fasteo 9y ago
  True, but think about non-necessary vs beneficial vs optimal. "Gluconeogenesis is extremely expensive" [1] [1] https://www.youtube.com/watch?v=Og8PTdjVAWE https://www.youtube.com/watch?v=Og8PTdjVAWE
  - dualogy 9y ago
    The key to cheap and non-harmful GNG is to have copious amounts of fats circulating, at a keto-typical low weight that means copious intakes of fats too. GNG ideally shouldn't/wouldn't happen from proteins (unless intake is very high) but from other metabolic byproducts and the glycerol backbones of triglycerides. Then this process typically accompanies ketosis in which ketones (endogenously produced-from-fat-burning types-of-carbohydrate but not from GNG) power most (not all) glucose-but-not-fat-burning-capable cells. Fat-adapted where possible, ketone-adapted elsewhere, and lots of byproducts that ordinarily would be "useless and to be excreted" (not just glycerol but also lactate, pyruvate etc) can now feed into (non-protein) GNG without the complications and expenses and downsides of protein-to-glucose GNG.
XFrequentist 9y ago
Anecdatum, but I play competitive basketball on a very low carbohydrate diet (<20g/day), and feel just fine, so necessary seems necessarily false. The missing concept (in the brief quote in your comment) might be "fat adaptation", which takes (in my experience) 2-4 weeks (details: http://www.artandscienceoflowcarb.com/the-art-and-science-of-low-carbohydrate-performance/ http://www.artandscienceoflowcarb.com/the-art-and-science-of... ) One certainly can fuel activity with carbohydrates, but a fat-adapted person should have no trouble with physical activity on a (very) low carbohydrate diet. Interestingly, a fat-adapted athlete can still use carbohydrates for supplemental fuel before, during, or immediately following extreme exertion (no adaptation is required for short-term use of carbohydrates).
- fasteo 9y ago
  OP here. Fully agree. I do 2-3 keto cycles (5 weeks) per year. Not against keto diet. But note that the context of this study is healthspan and mortality, not athletic performance, weight loss, etc. It was just warning that this study does not warrant that keto diet is good for your health in the long term. The title is a bit misleading.
  - XFrequentist 9y ago
    Fair to say the study results themselves (as opposed to the authors' assertion quoted in the gp) don't really pertain to the health effect of low carb/keto, at all (ie null rather than evidence for or against)?
- bitexploder 9y ago
  The book The Lore of Running covers this as well. For normal day to day things this is fine. However, it is extremely understudied with minimal evidence it works for everyone. https://www.google.com/amp/s/www.runnersworld.com/newswire/do-low-carb-diets-improve-endurance-performance%3Famp https://www.google.com/amp/s/www.runnersworld.com/newswire/d... It is still unclear, and dubious to claim, that you can operate at 80+ percent VO2 max on hard work outs. Maybe for short workouts or workouts with bursts of activity e.g. basketball. You can also undo fat adaptation pretty easily. The answer is it depends, but there is little evidence it has any large negative effects. Questions on peak performance vs "feeling fine" will be interesting to see in studies.
roystonvassey 9y ago
>during physical activity As someone who has been on a low-carb diet for 3 years, on and off, I definitely don't notice any difference in performance, mood or productivity while on a low-carb diet. Too many people (esp. those in a desk job) over estimate their physical activity levels and think they need more carbs. Sure, if you're an athlete, all this doesn't apply to you. But, for the vast majority (who in the present day) lead highly sedentary lifestyles, it's about time we encourage them to get off carbs as much as possible.
deleted 9y ago
[deleted]

by fasteo 9y ago

internetman55 9y ago

That is about what I have been eating naturally (~150-250g carbs daily, pretty much from oats, potatoes, sweet potatoes, dairy, and 1-2 servings of fruit per day).

smn1234 9y ago

I think the assumption there is very-low carb (as a macro-nutrient, not "healthy" v "unhealthy") can be better if _lower_ carb demonstrates improved outcomes... ?

randallsquared 9y ago

> Importantly, a certain amount of carbohydrate is necessary to meet short-term energy demands during physical activity [...] Why would they make such a claim? Anyone who has done keto and worked out has probably had the experience of doing quite a lot of physical activity while having had no carbohydrate intake at all for half a day before, or more.

mkrecny 9y ago
Half a day of carb restriction wouldn't meaningfully deplete glycogen stores.
- didgeoridoo 9y ago
  I’ve been <20g of carbs per day since February 2016. My athletic performance was impaired for the first 6-8 weeks, but has since increased dramatically. At low circulating insulin levels, most cells in your body can efficiently metabolize fatty acids. For the minority of cells that cannot, your liver converts protein into sugar by a process known as gluconeogenesis. It’s very possible to be a performance athlete and eat very low carb.
- arkades 9y ago
  80m of exercise is enough to deplete muscle glycogen to as-near-zero as makes no difference. In a sessile starvation state glycogen stops being a meaningful energy source after 2 days, with the majority of it depleted in approximately 8-12 hrs (it's non-linear). Depending on one's baseline physical activity and what they mean by "half a day," sure, glycogen stores can be reasonably depleted. That said, glucogenic amino acids can replenish glucose stores, which can ultimately become glycogen. Glycogen remains low only in the context of low-carb and low-total calories, so what glycogen is replenished is soon exhausted.
- randallsquared 9y ago
  ...even if you'd already been doing keto on an ongoing basis?
philfrasty 9y ago
„no carbohydrate intake at all for half a day before“ no way your body was in ketosis.
- X86BSD 9y ago
  It takes about a week of < 20g/carbs a day for the body to go into ketosis. This is born out by buying keto strips and testing your urine.
  - rblatz 9y ago
    It takes 3 days for me to hit ketosis at that carb level.
  - gebeeson 9y ago
    I can achieve 'dark purple' on strips in two to three days without drastic dietary or exercise extremes. This is one of my biggest sticking points with articles that make generalizations about body functions. There are always outlying examples and exceptions.
    - corry 9y ago
      You probably already know this, but in case other readers don't, the depth of color on keto sticks is NOT a measure of "how deeply in ketosis" you are. The depth of color indicates how concentrated ketones are in your urine, which is impacted by (1) the amount of ketones your body is producing, and, very importantly, (2) your hydration level (i.e. how diluted your urine is). For newbies, if the stick is pink AT ALL, congrats, you're in ketosis. Don't make the depth of color a big goal.
  - SiddarthaBuddha 9y ago
    this is not true for all people and urine tests are not considered reliable. I can get into ketosis in a single day of fasting
  - fasteo 9y ago
    A little known fact is that you can induce ketosis while eating carbs. The biochemistry here is clear: You get into ketosis when you oversupply acetyl groups to the TCA cycle. Adding MCT (Medium Chain triglycerides) to your diet will do this.
fasteo 9y ago
At most, your brain can run with 75% ketones/25% glucose. Other organs (kidneys, red blood cells, cornea) need about 15-25 grams/carb per day. If you do not get glucose from diet, your body will build it (gluconeogenesis). Must see if you want to understand/practice keto right: https://www.youtube.com/user/chrismasterjohn/videos https://www.youtube.com/user/chrismasterjohn/videos
- GreaterFool 9y ago
  I started a keto diet 2 weeks ago. As far as my research into keto goes eating too much carbs kicks you out of ketosis (duh!) and eating too much protein triggers gluconeogenesis which also kicks you out of ketosis. Which is a shame because I'd be happy to eat fatty steak and fatty pork all the time! Keto guidelines generally say 30g carbs per day and that's what I'm going to stick to (net carbs; I want to eat avocados!). So typical keto diet should work fine with what you say about carb requirement. I don't have any particular desire to go all the way to 0 (or some really low number) and if I have some carb budget left I'm happy to get a latte. Starbucks says grande almond latte has 9g carbs (5g sugars). Perfect to tidy it up to just below 30g/day.
  - have_faith 9y ago
    What was your motivation for starting the keto diet?
    - benballjr 9y ago
      Not sure what this other guy will say, but for the vast majority of people it is for major weight loss, not necessarily lifestyle or belief that it is a "superior" health approach. This is my experience from Reddit's keto and loseit communities anyway.
    - GreaterFool 9y ago
      I've been weightlifting for a while and got fitter and stronger but the progress has been slow so I decided to change things up. I read about keto and the more I read the more awesome it seemed. Since I switched to keto I have an amazing mental clarity. Literally from the moment I open my eyes in the morning I feel lucid (before I'd take me maybe 30 min and maybe a coffee to "wake up"). And I feel lucid all the way until I fall asleep (I don't get tired before falling asleep. Just go to bed, sleep). Nice and steady energy throughout the day. Also, I feel noticeably better overall. My max strength suffered a little bit (keto can take 1-3 months to adjust) but I'm more energetic throughout the day, mind and body.

rhinoceraptor 9y ago

There’s no such thing as necessary carbohydrates. The body is capable of producing all the glucose it needs.

fasteo 9y ago
True, but think about non-necessary vs beneficial vs optimal. "Gluconeogenesis is extremely expensive" [1] [1] https://www.youtube.com/watch?v=Og8PTdjVAWE https://www.youtube.com/watch?v=Og8PTdjVAWE
- dualogy 9y ago
  The key to cheap and non-harmful GNG is to have copious amounts of fats circulating, at a keto-typical low weight that means copious intakes of fats too. GNG ideally shouldn't/wouldn't happen from proteins (unless intake is very high) but from other metabolic byproducts and the glycerol backbones of triglycerides. Then this process typically accompanies ketosis in which ketones (endogenously produced-from-fat-burning types-of-carbohydrate but not from GNG) power most (not all) glucose-but-not-fat-burning-capable cells. Fat-adapted where possible, ketone-adapted elsewhere, and lots of byproducts that ordinarily would be "useless and to be excreted" (not just glycerol but also lactate, pyruvate etc) can now feed into (non-protein) GNG without the complications and expenses and downsides of protein-to-glucose GNG.

XFrequentist 9y ago

Anecdatum, but I play competitive basketball on a very low carbohydrate diet (<20g/day), and feel just fine, so necessary seems necessarily false. The missing concept (in the brief quote in your comment) might be "fat adaptation", which takes (in my experience) 2-4 weeks (details: http://www.artandscienceoflowcarb.com/the-art-and-science-of-low-carbohydrate-performance/ http://www.artandscienceoflowcarb.com/the-art-and-science-of... ) One certainly can fuel activity with carbohydrates, but a fat-adapted person should have no trouble with physical activity on a (very) low carbohydrate diet. Interestingly, a fat-adapted athlete can still use carbohydrates for supplemental fuel before, during, or immediately following extreme exertion (no adaptation is required for short-term use of carbohydrates).

fasteo 9y ago
OP here. Fully agree. I do 2-3 keto cycles (5 weeks) per year. Not against keto diet. But note that the context of this study is healthspan and mortality, not athletic performance, weight loss, etc. It was just warning that this study does not warrant that keto diet is good for your health in the long term. The title is a bit misleading.
- XFrequentist 9y ago
  Fair to say the study results themselves (as opposed to the authors' assertion quoted in the gp) don't really pertain to the health effect of low carb/keto, at all (ie null rather than evidence for or against)?
bitexploder 9y ago
The book The Lore of Running covers this as well. For normal day to day things this is fine. However, it is extremely understudied with minimal evidence it works for everyone. https://www.google.com/amp/s/www.runnersworld.com/newswire/do-low-carb-diets-improve-endurance-performance%3Famp https://www.google.com/amp/s/www.runnersworld.com/newswire/d... It is still unclear, and dubious to claim, that you can operate at 80+ percent VO2 max on hard work outs. Maybe for short workouts or workouts with bursts of activity e.g. basketball. You can also undo fat adaptation pretty easily. The answer is it depends, but there is little evidence it has any large negative effects. Questions on peak performance vs "feeling fine" will be interesting to see in studies.

roystonvassey 9y ago

>during physical activity As someone who has been on a low-carb diet for 3 years, on and off, I definitely don't notice any difference in performance, mood or productivity while on a low-carb diet. Too many people (esp. those in a desk job) over estimate their physical activity levels and think they need more carbs. Sure, if you're an athlete, all this doesn't apply to you. But, for the vast majority (who in the present day) lead highly sedentary lifestyles, it's about time we encourage them to get off carbs as much as possible.

deleted 9y ago

[deleted]