Organizm nie wytwarza węglowodanów z białka ?

[Waldek]

Znalazłem coś takiego w necie. Wg Owsleya (typ od diety "zero-roślinnej") organizm, któremu nie dostarczamy żadnego pokarmu roślinnego przestawia się całkowicie na ketony. Bzdury?

Bear basically believes that ongoing gluconeogenesis does not occur, rather, on a high fat, low protein, zero carb diet the body will switch to using ketones (made from fat) instead of glucose, for those cells that cannot use fat (a minority of them). Therefore, he feels that muscle wasting will only occur on long term fasting (starvation), as the body would attempt to hold onto the last bit of fat stores, because they are so vital in protecting the body (insulation, cushioning, etc.).

Bear believes while proteins are constantly being recycled and the body is extremely conservative in their use, muscle is never broken down for energy metabolism, except in extreme cases like starvation. He believes that glycogen stores have a very slow turnover, due to the large use of ketones instead of glucose. Bear's message is to eat lots of animal fat, and keep the protein intake low, even while body building.

Bear wrote:
Actually, Dean, the brain's requirement for glucose is nearly 100% covered by the 'ketone bodies' which are produced during fat metabolism, and NO gluconeogenesis will take place on a high fat diet... period. Gluconeogenesis is a fasting process that only begins after the point where there are NO more ketones OR glycogen available. The body always spares protein, and it is only under severe conditions that protein is ripped apart for the glucose spine it contains.


Bear wrote:
An all meat diet is actually a 'low protein' diet. It is high in fat, not protein. High protein diets are bad for your body.


Bear wrote:
Rats 'fed a high protein low carb diet' is an oxymoron, there is no 'high protein' diet that an animal can live on. There are two types of extreme diet- high fat and high carb. Protein requirement is around 15 - 25%. More is not necessary or good and sustained values of less than ~15 may incur a reduction in overall health if maintained for a long enough period. In an emergency, any animal can survive on 100% fat for weeks, even months.


Bear wrote:
Basically you have to be doing something very wrong to experience this process. This is bourne out by the lack of muscle loss on a 100% fat diet- the body can strictly conserve protein.


Bear wrote:
The all meat diet is NOT in strict terms a 'low carb diet', it is a high FAT diet. It is possible to survive a verylong period on not pretein as well as not carbs, in other words on fat alone- many months can go by. In a shortage of dietary protein the body becomes very conserving of amino acids and if not damaged, does not break them down, but recycles them


Bear wrote:
I thought I had already covered this misconception: You CANNOT raise your blood glucose level above your normal fasting level by gluconeogenesis, no matter what. Gluconeogenesis cannot and will not even take place so long as there is enough fat intake, period. 'Excess' dietary protein is broken down and discarded, never converted to glucose except in an emergency- such as under heavy and extensive fasting- and then only after all the stored glycogen in liver and muscle has been converted first. The liver under these circumstances only produces from protein the exact amount necessary to maintain the normal level. Only dietary intake can drive the blood glucose level above your baseline.


Bear wrote:
So long as your body has retained any level of glycogen (the liver usually is about 40% glycogen, plus some is stored in muscles) you will not tear apart proteins for glucose- a simple and rapid enzymatic process cuts the the poly-sacccarhide glygocen into its constitutent mono-saccarhide units, i.e., glucose. Long, severe fasting is necessary for all glycogen to be depleted, not 48 hrs, let alone 24.


Bear wrote:
There are no 'unique nutrients' required for humans which can be found in vegetables. Humans live very well indeed on just muscle tissue with sufficient fat. This is a fact and is history, so all the conjecture and theorising in the world will not change it. If the body was able to create glucose on demand from ripping he core out of protein, then why is 100% protein so deadly it can kill you in about a week to ten days? Adding dietary fat or carbs prevents this poisoning. The fact is gluconeogenesis is rare except under two conditions, severe fasting and recovery from starvation-induced bodyfat depletion on a zero carb diet. Then the adipose tissues are re-built by diverting a small amount of blood sugar which stimulates mild gluconeogenesis.

The statement that glycogen is depleted in 3 days is simple nonsense, the liver holds a vast supply of glycogen and a person who is fully keto-adapted uses so little glucose that glycogen will last for a week or more.


Bear wrote:
You cannot eat 'straight protein'- it is more than constipating, it is dangerously toxic. Dietary protein content should never go above 40 or so percent and 20% is quite a good percentage, even for a bodybuilder. The diet should include 60-80% fat. Calling any workable diet 'high protein' is misleading.


Bear wrote:
The body does do a bit of glucose-making to stabilise glycogen/glucose when needed, just as it will if you are below your native 'fatostat' setting, say you have dropped to around 5%, like a competing body builder- to say at that low fat level requires exact matching of caloric intake to calories burned, coupled with exercise. It is important the the diet supply sufficient protein, of course to spare incorporated protein. In dealing with protein in the muscles etc, one should be aware that the body is constantly breaking down and rebuilding the various protein structures anyway- like a mad mob of tiny housebuilders who dismantle the brick walls and pass the bricks around, rebuilding them as fast as they are taken apart- I have no idea why, but this is how it works. I think this is why you lose muscle mass you gain from exercising, if you don't continue to exercise. The body is very conservative relative to carrying mass, and does not maintain structures like muscle size and strength at levels beyond perceived current 'need'.


Bear wrote:
What made the 'high protein' dieters sick? That's dead simple- lack of adequate fat intake. There is actually no such thing as a 'high protein' diet, Protein does not need to be higher than 20% for health and must never go above 50%. There are, therefore, only high-carb and high-fat diets.


Bear wrote:
Protein cannot and must not be the 'major macro nutrient', fat must be. High protein intake is very toxic.


Bear wrote:
Yes, any and all 'excess' protein is indeed excreted. Protein is constantly being used, to build up, tear down, recycle- and any excess is then excreted, you only really need a few grams- (max of ~30 if you are a 200 pound pro), a day even if you are building massive musculature (Mr Olympia). You cannot/will not make ANY glucose from it unless you are fasting for a long time, or starving. All-meat eaters do not need much glucose- other than amount easily furnished by glycogen- ketones replace glucose.


Bear wrote:
Anyone who doesn't drink coffee and 'experiences' hyper- or hypo-glycemia, is NOT on a zero carb diet, simple as that. Give away this 'protein makes glucose' nonsense, it is false and makes you appear just plain stupid.

Protein only is toxic, will make you very sick if done for a period, but does NOT initiate gluconeogenesis after a single meal. Give it away, please. You simply don't know what you are talking about.


Bear wrote:
Protein NEVER raises insulin and does not form blood sugar. Your statements to the contrary are both false.


Bear wrote:
If additional glucose is needed in a fat-fed person, it is obtained from glycerol- not protein.


Bear wrote:
Lipolysis is stimulated by dietary fat when, and only when- you are carrying more body fat than your body 'wants' or needs, a level I have called your 'fatostat'. Your metabolism prefers to use dietary-sourced fat, remember bodyfat comes from glucose conversion only so your body will conserve it if it can, and will replace it if it goes 'too low'- this is the one stimulus for glucose-from-protein- i.e., recovery from severely low levels of body fat from fasting or starvation, on an all meat regime with adequate fat and protein intake, but no carbs.


Bear wrote:
Paleo people hunted many kinds of animals, some were high in body fat, some very lean. In the situation of low fat, they discarded much of the lean. You CANNOT live on high protein and a 'low to moderate' level of fat. I don't care what anyone wrote, it is a myth: 11% of calories with no carbs will kill you dead in a few weeks, that is DEAD, you know, 'no longer alive'. Protein levels above 50% do not leave enough room for the fat that you have to have. Very little protein is necessary for health, as little as 5% will do for a very long period, it willnot help build more mass, however it will maintain what you have.


Bear wrote:
How much protein is immaterial. I ate, and still eat- enough. Eat what it takes to satisfy on 80/20, don't worry about numbers. I usually liked around a couple of pounds(1 kg)/day of beef. That works out to about 150-200 gm. You need very little 'extra' protein- (or calories) - to build muscle mass, contrary to what you will read in the supplement-owned mags.


Bear wrote:
Protein in any amount does not damage the kidneys. You need to drink an adequate amount of water. The kidneys WILL suffer on any diet, if you get dehydrated. Bodybuilder.com is as full of dietary myth as Joe Weider's Muscle and Fitness, Flex, Ironman, Musclemag or that awful GNC rag. Yes indeed, high carbs are absolutely great at building intramuscular fat,looks good, big and meaty, but carbs strongly limit any addition of larger muscle fibres (real muscle size).


Bear wrote:
Protein are degraded ONLY under circumstances related to severe fasting and starvation. The claim that insulin is a 'growth factor' is incorrect. There is an 'insulin-like' growth factor, however even it has been shown to be ineffective in stimulating skeletal muscle growth, something it was heavily tauted for by the bodybuilding community.


Bear wrote:
At 5gm/day of glucose turnover, I usually get that amount in cream etc. Otherwise from glycerol. No protein is used , period- GNG of protein simply does not, and cannot occur on this diet- ever. And, please note- any research that says it does is bogus, so curb your indignation, if any.

Many attempts have been made, feeding a normal intake of food on a zerocarb regime to elicit tagged glucose made from tagged proteins in the diet, hence proof of GNG- with zero results. All the theoretical dissertations and bogus research in the world cannot over-ride this sort of evidence, let alone all the rest of the published data disproving its existence. So if 'constant gluconeogenesis' is a part of your 'belief system', and thinking that way does not cause you any problems, then it is perfectly ok for you (the black box), however it is not a based on fact anymore than a belief in 'walking on water' can be shown to be based on fact.


Bear wrote:
Basically gluconeogenesis is a destructive process in which the body rips the poly-glucose core out of protein molecules (glucose forms the support structure for strings of amino acids) in starvation. These sacrificial proteins are usually sourced from the muscle tissues. This process is very destructive to the tissues and is only resorted to under extreme circumstances while in a fed state, such as on a no carb intake combined/coupled with insufficient fat intake as well. Starvation and long term fasting brings it on, bigtime.

A zero-carb all meat, 80/20 (by calories: fat/protein) diet delivers the necessary small amounts of glucose from glycerol- while most of the daily glucose requirement (as seen in a mixed diet) is replaced by ketones, which- like glycerol- are by-products of fat metabolism. If you are properly using the ketones in your body as food (glucose replacement) - you will not see them spilling in your urine. Dietary protein is never used to make glucose in a fat-sufficient dietary situation.

Basically you have to be doing something very wrong to experience this process. This is bourne out by the lack of muscle loss on a 100% fat diet- the body can strictly conserve protein.


Bear wrote:
What does it take to stop the mindless prattle and nonsense about protein turning into glucose?


And, I love this one on rubbish...

Bear wrote:
All vegetable carbs other than cellulose (they ALL convert to glucose), once set free of the cell by processing or cooking are absorbable by the human gut. The residue of indigestible vegetable protein and any unabsorbed carbs feed a massive bacterial colony in the large intestines (80+% of feces on a mixed or vegetable diet is dead bacteria). The bacteria may excrete toxins which enter your blood stream. The residue from vegetation a fibrous, rough material which scratches the sensitive lining of you small intestines and causes a callus to form over time as a defensive reaction. Calluses on the lining of the small intestine interfere with the extraction of nutrients. Vegetables of any sort have nothing whatsoever to recommend them, other than as dire emergency survival fare- to temporarily stave off death from acute starvation.

zródło >> http://magicbus.myfreeforum.org/Bear_s_take_on_macro_ratios_ketones_and_gluconeogenesis_about1014.html

http://forum.lowcarber.org/showthread.php?t=287013&page=1&pp=15

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[Goska999]

Co wiem - jeśli  nie dostarczymy odpowiedniej ilości węgli, oorganizm wytwarza je z białka.
A może coś pomyliłam?