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  #1051   ^
Old Fri, Jun-14-13, 12:29
TigerLily1's Avatar
TigerLily1 TigerLily1 is offline
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Basically, without protein we will perish. Therefore, our options are only a choice of a ballast for our essential protein, which boils down to either Carbs or fat, but *not* both.


The Fruitarian community strongly disagrees with that lol, on their sites they claim we don't really need protein, same way people in the LC circles claim we don't really need carbs. There are many who lived their life on fruit and perhaps other vegan carbs as well (no grains or brans etc)

I personally don't think we will perish without protein, I do better on protein, but don't think I will perish if I don't eat it.
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  #1052   ^
Old Fri, Jun-14-13, 12:35
Liz53's Avatar
Liz53 Liz53 is offline
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Plan: Mostly Fung/IDM
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Quote:
Originally Posted by LoveMagnet
It actually depends on the particular amino acid profile. Only certain amino acids can be converted into glucose. Others are sent directly into cellular respiration for ATP production. So it does depend on the type of meat/food you eat.



This is so interesting - I'd love to know which amino acids are converted to glucose. Just so you know, I'm not struggling with carbs vs fat. I know my body works best with 65-75% fat each day and I'm almost always in the 65-68% range. In terms of carbs, I try to keep them as low as possible (20-30 per day currently) with protein as the remainder. This equates to 85-100 grams protein per day (I shoot for 90). My lean mass is ~100 lbs, according to one of those not particularly accurate fat % scales at the gym. Do you think I'm on the right track?
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  #1053   ^
Old Fri, Jun-14-13, 12:56
teaser's Avatar
teaser teaser is offline
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Plan: mostly milkfat
Stats: 190/152.4/154 Male 67inches
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Quote:
Originally Posted by Liz53
Thanks, makes sense. I'm also going to copy and paste an earlier question that you may not have seen in this volley - I wonder if you have knowledge/opinions:

Has anyone read any convincing studies or observations on when the body converts "excess" protein to glucose? Is it any time that the body ingests more protein than it needs for immediate repair? Or is it dependent on the body (or the brain, most likely) needing a bit of glucose at the moment and protein is available? If both carbs and protein were available, would it be more likely to engage in direct carb burning or gluconeogenesis? Can/will the body convert protein to fat for storage or is gluconeogenesis the only mechanism for using that excess protein?



Closest thing I've seen is this;

http://www.ketotic.org/2012/08/if-y...rn.html#⁵

But it doesn't quite address our issue; we need something specific, where levels of gluconeogenesis on a very low carb diet in response to various fat vs protein ratios are measured.

It doesn't seem to be very hard to find an expert or guru who'll take either position--extra protein will be made into glucose, or only the amount you need will be synthesized, any other extra protein simply oxidized for energy. I've seen Dr. Michael Eades take this second stance a number of times.

This bit;

Quote:
It was therefore proposed by Cahill, Felig, and Marliss and their associates (7, 12, 13, 20) that the reduced glucose production rate in starvation was due to the reduced availability of gluconeogenic substrates; hence, gluconeogenic precursor supply was rate-limiting for glucose production rate.


Which probably comes closest to the point, now that I look at it again. Think I'm switching sides here, at least when in the highly-ketogenic state that parallels fasting.

They counter this here;

Quote:
In contrast, the findings of several kinetic studies performed in human and dog do not support this proposal (1, 30, 34, 38). These studies in postabsorptive subjects employed either the isotope dilution or hepatic vein catheterization techniques and failed to show any significant change in glucose production rate in response to infusions of substantial quantities of alanine, lactate, and glycerol even when there was a fivefold increase in the hepatic uptake of the infused substrate


But here, they're just plain wrong. In starvation, most of the glucose production comes from gluconeogenesis. During a shorter term fast (postabsorptive) most of the glucose produced will come from the break down of glycogen. In the first case, gluconeogenesis may actually be rate-limiting for glucose production, in the second, it's not--so increased substrate wouldn't necessarily increase glucose appearance rate.

Quote:
Our data so far indicate that under almost any physiological situation, an increase in gluconeogenic precursor supply alone will not drive glucose production to a higher level, suggesting that factors directly regulating the activity of the rate-limiting enzyme(s) of glucose production normally are the sole determinants of the rate of production; hence, there will be no increase in glucose production if the increase in gluconeogenic precursor supply occurred in the absence of stimulation of the gluconeogenic system.


They seem to make the mistake of assuming that glucose appearance is a good proxy for gluconeogenesis, when it just plain isn't. Which I find kind of disappointing--since I love that they're at least trying to address this issue in some sort of organized way.
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  #1054   ^
Old Fri, Jun-14-13, 12:57
Nancy LC's Avatar
Nancy LC Nancy LC is offline
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Quote:
Originally Posted by TigerLily1
I personally don't think we will perish without protein, I do better on protein, but don't think I will perish if I don't eat it.

kwashiorkor
I would think a lot of vitamin deficiencies would cause issues too, like your myelin sheaths dissolving due to lack of B12.
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  #1055   ^
Old Fri, Jun-14-13, 13:01
TigerLily1's Avatar
TigerLily1 TigerLily1 is offline
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Quote:
Originally Posted by Nancy LC
kwashiorkor
I would think a lot of vitamin deficiencies would cause issues too, like your myelin sheaths dissolving due to lack of B12.


Sure, but nowadays one can have B12 without eating meat, so the statement one would perish is not true.

As you know I am a heavy meat eater, but I believe many survive and flourish without eating meat or even plant protein.
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  #1056   ^
Old Fri, Jun-14-13, 13:11
Liz53's Avatar
Liz53 Liz53 is offline
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Plan: Mostly Fung/IDM
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Quote:
Originally Posted by TigerLily1
I believe many survive and flourish without eating meat or even plant protein.


Really? You don't think we need amino acids for repair of lean tissue? Where do those amino acids come from if not from food?

And thanks, teaser, for that link and all the other excerpts. Very interesting stuff.
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  #1057   ^
Old Fri, Jun-14-13, 13:15
teaser's Avatar
teaser teaser is offline
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Plan: mostly milkfat
Stats: 190/152.4/154 Male 67inches
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Quote:
Originally Posted by TigerLily1
The Fruitarian community strongly disagrees with that lol, on their sites they claim we don't really need protein, same way people in the LC circles claim we don't really need carbs. There are many who lived their life on fruit and perhaps other vegan carbs as well (no grains or brans etc)

I personally don't think we will perish without protein, I do better on protein, but don't think I will perish if I don't eat it.


I was actually thinking about this earlier, looking at LoveMagnet's protein intake. I see a lot of arguments that we need "extra protein" on a low carb diet, to preserve lean mass etc. But... if we really need only 30 grams of glucose a day, and half of that can come from glycerol, then how much do we really need? In total starvation, I've seen studies where protein loss was only about seven percent of calories after about three weeks. And children on the ketogenic diet manage to be in positive nitrogen balance (grow) with a pretty low protein percentage (but kids can eat a lot of food).

Not sure what my point is. Maybe I just like hearing myself talk today.

Oh yeah, the fruitarians. Some long-term fruitarians really look like they're wasting away--but I'm amazed at how long this seems to take. (I tend to believe these guy's claimed diets precisely because they're wasting away).
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  #1058   ^
Old Fri, Jun-14-13, 13:23
Liz53's Avatar
Liz53 Liz53 is offline
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Posts: 6,140
 
Plan: Mostly Fung/IDM
Stats: 165/138.4/135 Female 63
BF:???/better/???
Progress: 89%
Location: Washington state
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Quote:
Originally Posted by teaser
I was actually thinking about this earlier, looking at LoveMagnet's protein intake. I see a lot of arguments that we need "extra protein" on a low carb diet, to preserve lean mass etc. But... if we really need only 30 grams of glucose a day, and half of that can come from glycerol, then how much do we really need? In total starvation, I've seen studies where protein loss was only about seven percent of calories after about three weeks. And children on the ketogenic diet manage to be in positive nitrogen balance (grow) with a pretty low protein percentage (but kids can eat a lot of food).

Not sure what my point is. Maybe I just like hearing myself talk today.

Oh yeah, the fruitarians. Some long-term fruitarians really look like they're wasting away--but I'm amazed at how long this seems to take. (I tend to believe these guy's claimed diets precisely because they're wasting away).


I've always thought satiety was the main reason for increased protein on a low carb diet (though the New Atkins authors refer to adequate protein rather than increased), rather than preservation of lean mass (I see that as more of a by-product). Of course it all comes down to the question: How much protein do we really need? And are we looking for minimal performance or optimal? And what variables can change the amount we need? I see a lot of speculation around these questions and not a lot of real research.

I do recall a study from a couple of years ago by George Bray, I believe, where he found that dieters that ate more protein than the control group had better compliance and better results. I think he proposed to be comparing low carb vs low fat, but the low carb arm was not particularly low carb, and the low fat arm was not particularly low fat, but the increased protein group did well.
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  #1059   ^
Old Fri, Jun-14-13, 13:53
Frederick's Avatar
Frederick Frederick is offline
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Plan: Atkins - Maintenance
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Quote:
Originally Posted by TigerLily1
The Fruitarian community strongly disagrees with that lol, on their sites they claim we don't really need protein, same way people in the LC circles claim we don't really need carbs. There are many who lived their life on fruit and perhaps other vegan carbs as well (no grains or brans etc)

I personally don't think we will perish without protein, I do better on protein, but don't think I will perish if I don't eat it.


The only way a "zero" carb diet would be sustainable is with adequate protein. On zero carbs, without a source of animal protein, I'm not sure how a 100% fat diet would work, since I assume the fruits and veggies aren't a preferred option on "zero" carb.
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  #1060   ^
Old Fri, Jun-14-13, 16:22
teaser's Avatar
teaser teaser is offline
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Plan: mostly milkfat
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http://jn.nutrition.org/content/136/1/319S.long

Found this interesting regarding leucine;

Quote:
In addition to the direct conversion of amino acid carbon to gluconeogenesis precursors, there is also the contribution of the BCAA to glucose recycling via the glucose-alanine cycle (15,49). There is a continuous flux of BCAA from visceral tissues through the blood to skeletal muscle where transamination of the BCAA provides the amino group for production of alanine from pyruvate with a corresponding movement of alanine from muscle to liver to support hepatic gluconeogenesis. Although the impact of the glucose-alanine cycle has been debated, Ahlborg et al. (49) reported that alanine accounted for 40% of endogenous glucose production during prolonged exercise. Under normal conditions, alanine arising from BCAA nitrogen likely accounts for ∼25% of gluconeogenesis from amino acids (8). These studies provide evidence for the linkage between dietary protein and glucose homeostasis.



There's some mouse studies out there where dietary leucine was restricted, and body fat became rapidly depleted.
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  #1061   ^
Old Fri, Jun-14-13, 16:36
Liz53's Avatar
Liz53 Liz53 is offline
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Posts: 6,140
 
Plan: Mostly Fung/IDM
Stats: 165/138.4/135 Female 63
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Location: Washington state
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Interesting article, teaser, and surprisingly easy to understand (esp. for me with no formal biochem background). I notice that one of the co-authors is Donald Layman whom Jimmy Moore interviewed here.

This must be one of the studies that Dr Layman refers to in the interview. Googling foods high in leucine, I come up with eggs, chicken, moose, but no beef. It's all coming together for me now. Thanks so much for digging that up - it gives me a clearer idea of how to proceed.
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  #1062   ^
Old Sat, Jun-15-13, 02:29
TigerLily1's Avatar
TigerLily1 TigerLily1 is offline
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Plan: No idea
Stats: 145/-/125 Female 165
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Progress: 125%
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Quote:
Originally Posted by Frederick
The only way a "zero" carb diet would be sustainable is with adequate protein. On zero carbs, without a source of animal protein, I'm not sure how a 100% fat diet would work, since I assume the fruits and veggies aren't a preferred option on "zero" carb.


Agreed, I misinterpreted your statement, I didn't realise you said it in the ZC context.
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  #1063   ^
Old Sat, Jun-15-13, 09:13
LoveMagnet LoveMagnet is offline
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Quote:
Originally Posted by Liz53
This is so interesting - I'd love to know which amino acids are converted to glucose. Just so you know, I'm not struggling with carbs vs fat. I know my body works best with 65-75% fat each day and I'm almost always in the 65-68% range. In terms of carbs, I try to keep them as low as possible (20-30 per day currently) with protein as the remainder. This equates to 85-100 grams protein per day (I shoot for 90). My lean mass is ~100 lbs, according to one of those not particularly accurate fat % scales at the gym. Do you think I'm on the right track?


Personally? No. I think everyone should be totally zero carb with about 80/20 ratio, but that's my personal opinion.

I can't completely back that up yet as I haven't done my own scientific studies to confirm this. This will be the basis of my dissertation in post-grad. school coming up. What I have studied does lead to conclude, however, that any amount of carbs (over 5 grams...the few in eggs or even lettuce aren't a big deal if you don't eat a lot of that stuff) is poison. It's like the difference between one drink of liquor and 10. 1 is still poisonous, it's just less of it.

However, you should continue to do what you think is best for you.

Amino Acid Catabolism

This shows which amino acids turn into ketones and which turn into glucose. Some are capable of both.
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  #1064   ^
Old Sat, Jun-15-13, 09:15
LoveMagnet LoveMagnet is offline
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Quote:
Originally Posted by teaser
I was actually thinking about this earlier, looking at LoveMagnet's protein intake. I see a lot of arguments that we need "extra protein" on a low carb diet, to preserve lean mass etc. But... if we really need only 30 grams of glucose a day, and half of that can come from glycerol, then how much do we really need? In total starvation, I've seen studies where protein loss was only about seven percent of calories after about three weeks. And children on the ketogenic diet manage to be in positive nitrogen balance (grow) with a pretty low protein percentage (but kids can eat a lot of food).

Not sure what my point is. Maybe I just like hearing myself talk today.

Oh yeah, the fruitarians. Some long-term fruitarians really look like they're wasting away--but I'm amazed at how long this seems to take. (I tend to believe these guy's claimed diets precisely because they're wasting away).


I think people generally need a lot less protein than even most low carb diets suggest. That's only based on my personal experience, though.

I've been eating 40-45 grams of total protein daily for several years and it does not appear that I have lost any muscle mass. But, again, I don't work out at all. If you work out you'll need more than I eat.
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  #1065   ^
Old Sat, Jun-15-13, 14:35
Frederick's Avatar
Frederick Frederick is offline
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Plan: Atkins - Maintenance
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Location: Northern California
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Quote:
Originally Posted by TigerLily1
Agreed, I misinterpreted your statement, I didn't realise you said it in the ZC context.


Sure, I meant "animal" protein on a ZERO carb diet is essential.

Are you suggesting that one can live and thrive indefinitely on a ZERO protein diet?
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