Dietary Carbohydrates Impair Healthspan and Promote Mortality • Hacker News Board

Re: Dietary Carbohydrates Impair Healthspan and Promote Mortality

#51

Post by bitexploder » Fri, Oct 13, 2017, 1:38 PM UTC

XFrequentist wrote: post #37

fasteo wrote: post #11

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 absenc…

Anecdatum, but I play competitive basketball on a very low carbohydrate diet ( 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... ) One certainly can fuel activity with carbohydrates, but a fat-adapted person should have no trouble with…

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/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.

Re: Dietary Carbohydrates Impair Healthspan and Promote Mortality

#52

Post by iridium » Fri, Oct 13, 2017, 1:40 PM UTC

cup-of-tea wrote: post #35

I've read a lot of, often conflicting, dietry guidance. I have realised one very important thing: humans will very easily accept that something they enjoy is bad for them (see fat, sex etc.) So listening to what people say is bad for them is stupid. Instead I have taken a simpler approach: I observe the lifestyles of people who are healthy and live a long time. I have observed that eating simply "good, old-fashioned"…

Selection bias is something worth avoiding in understanding health studies. It’s quite likely that you know about these folks because they had the right genetics to be healthy outliers, and by extension, famous. It’s no different than saying I know x people who didn’t die of lung cancer due to smoking, which doesn’t change the implication that y% of smokers will always get lung cancer, we just haven’t figured out what fully constitutes your risk ( genetics etc)

Re: Dietary Carbohydrates Impair Healthspan and Promote Mortality

#53

Post by X86BSD » Fri, Oct 13, 2017, 1:40 PM UTC

philfrasty wrote: post #31

randallsquared wrote: post #25

Earlier quoted context omitted.

> 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.

„no carbohydrate intake at all for half a day before“ no way your body was in ketosis.

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.

Re: Dietary Carbohydrates Impair Healthspan and Promote Mortality

#54

Post by shlant » Fri, Oct 13, 2017, 1:40 PM UTC

I'm not surprised to see this at the top of HN considering how many people seem to be fans of the Keto Diet. I am very excited for people who find something that works for them, but I would be very wary of a study like this if you are looking for confirmation for multiple reasons:

1. The study "did not analyze which specific source of carbohydrates (e.g., sugar/refined carbs versus whole-grain products) may contribute to the detrimental effects of carbs observed, especially since income and wealth do impact the quality of dietary choices significantly."

This is HUGE. Any study or person that attempts to label an entire macronutrient as "bad" or "evil" is not helping anyone understand the whole picture. The most nutritious foods in the world are carbs. Many of the least nutritious foods are also carbs. Not distinguishing the two gets us nowhere.

2. With this study and most high fat/keto diet studies as well, the timeline is not long enough to tell us about true "lifespan" impact. This one is over 7.4 years. I know it's more difficult to do 10, 20, 30 year studies, but until something can be correlated over those timespans, I would not bet everything on that diet for longevity. There are a handful of generational studies, and almost all have shown that "high carb" or more specifically "plant based" ARE good for longevity. Not saying high fat aren't good for longevity as well, but we have yet to really see examples yet.

3. As many who have tried Keto specifically will tell you (as some have mentioned in the comments), it is very difficult to maintain a ketogenic state. You have to be very disciplined, and this is made harder when you are a social person. This is a big problem when talking about diet and longevity. If it's not fairly easy to maintain, then it's not a feasible diet for longevity where the average person is concerned.

4. As someone else mentioned, the percentage of carbs that the studies participants were eating were not even close to the level required for a Keto Diet

Re: Dietary Carbohydrates Impair Healthspan and Promote Mortality

#55

Post by CuriouslyC » Fri, Oct 13, 2017, 1:43 PM UTC

cageface wrote: post #24

This study is highly flawed: https://www.hsph.harvard.edu/nutritionsource/2017/09/08/pure... Be careful making any changes to your diet based on these "findings". The healthiest populations on the planet eat plenty of carbs, but not refined sugars.

I always wonder, when nutrition studies are usually so poorly designed and controlled, why people don't just look at the blue zone diets for nutrition guidance.

Re: Dietary Carbohydrates Impair Healthspan and Promote Mortality

#56

Post by neves » Fri, Oct 13, 2017, 1:43 PM UTC

keymone wrote: post #15

whalesalad wrote: post #2

I’ve been living a ketogenic lifestyle for a few years now. I go in and out once and a while but seeing the “fat is bad” theory thrown out the window with research like this makes it easier to remain committed. The trouble comes with the way society has been conditioned to have carbs with every meal. Like 90% of the food my peer group eats are surrounded in carbs. Even for a company-wide lunch in the office: the go-t…

totally agree. when there are no carbs around me - i have zero problems sticking to keto. whenever there's a party and some snacks - i'm in a danger zone unless i brought my own snacks in which case i'm a weirdo.

Don't bother about it. In the eyes of the others, everybody who is in a keto diet is already a weirdo :-)

Re: Dietary Carbohydrates Impair Healthspan and Promote Mortality

#57

Post by randallsquared » Fri, Oct 13, 2017, 1:44 PM UTC

philfrasty wrote: post #31

randallsquared wrote: post #25

Earlier quoted context omitted.

> 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.

„no carbohydrate intake at all for half a day before“ no way your body was in ketosis.

"Doing keto" implies less than 20g/day on an ongoing basis, at least as I understand it. On top of that, one might have eaten early in the previous day, eaten no breakfast, and be working out about lunch time, which would provide the "at least half a day without carbs of any kind".

It may be that you disagree, but I get the feeling that you ignored the "doing keto" part of my setup, and instead thought that the person in question was eating cake 12.5 hours before the workout. :)

Re: Dietary Carbohydrates Impair Healthspan and Promote Mortality

#58

Post by neves » Fri, Oct 13, 2017, 1:45 PM UTC

smn1234 wrote: post #16

trevyn wrote: post #8

I’ve found eating out socially on keto a big challenge (carbs still look delicious) until I found a hack: unreasonably large portions of salad, covered in salt. Salt is fucking delicious. Add olive oil too if you feel like it.

I drown everything in olive oil. Good, European protected designation of origin (PDO), protected geographical indication (PGI), and traditional specialities guaranteed (TSG) type olive oils. They're delicious. And you get full rather quickly. That feeling lasts. And I'm fairly certain the plant fat is not what's making us jiggly

Why so many labels in your oil? Isn't extra virgin sufficient?

Re: Dietary Carbohydrates Impair Healthspan and Promote Mortality

#59

Post by randallsquared » Fri, Oct 13, 2017, 1:45 PM UTC

mkrecny wrote: post #29

randallsquared wrote: post #25

Earlier quoted context omitted.

> 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.

Half a day of carb restriction wouldn't meaningfully deplete glycogen stores.

...even if you'd already been doing keto on an ongoing basis?

Re: Dietary Carbohydrates Impair Healthspan and Promote Mortality

#60

Post by bitexploder » Fri, Oct 13, 2017, 1:46 PM UTC

smn1234 wrote: post #16

trevyn wrote: post #8

I’ve found eating out socially on keto a big challenge (carbs still look delicious) until I found a hack: unreasonably large portions of salad, covered in salt. Salt is fucking delicious. Add olive oil too if you feel like it.

I drown everything in olive oil. Good, European protected designation of origin (PDO), protected geographical indication (PGI), and traditional specialities guaranteed (TSG) type olive oils. They're delicious. And you get full rather quickly. That feeling lasts. And I'm fairly certain the plant fat is not what's making us jiggly

Satiation from fat varies per individual. Typically it does not satiate any more than carbs (calorie for calorie) and lead to easy over consumption.