For those of you going for extra credit check out this amazing exchange between Lex Rooker and Dr. Kurt Harris. This exchange happened in the comments of Kurt's PaNu Weblog and would be a shame if it wasn't viewed by everyone.

Lex to Kurt

I have been eating one single meal per day of 1 ½ to 2 lbs of raw grass fed beef, bison, elk, or deer for several years now. I’ve experienced major health benefits and that is what keeps me on track. I’ve kept careful records of the changes that have occurred (blood glucose, weight, blood pressure, cholesterol, triglycerides etc) and there are some interesting issues that have appeared that are counter intuitive and rather puzzling. (my annual blood lab tests since I started this adventure are posted here if you are interested)
http://www.rawpaleoforum.com/journals/lex's-journal/

First, I initially believed that this way of eating would keep blood glucose low. This seemed to be true in the beginning, but after 18 to 24 months, blood glucose started creeping up to about 100 mg/dl and it pretty much stays at that level all the time. I’ve measured it every hour for days at a time (when awake & also if I awake during the night) and it no longer varies more than about 10 points one way or the other – even after meals. It just stays rock solid right around 100. With almost no carb intake whatsoever for over 3 years, what keeps fasting levels (I only eat once per day so I’m technically fasting for 23 hours per day) of blood glucose at the high end of the 'normal' range?

Second is the weight loss myth. I did initially loose lots of weight no matter how much I ate and independent of the fat/protein ratio of the food I ate. But then again after 18 to 24 months, I found I had to severely limit my food intake to keep my weight in check. I seem to do best when fat is between 60% and 70% of calories. At 80% of calories, I start to gain significant weight on the same amount of food and feel sluggish.

Short term results as far as weight and BG are concerned are far different than long term results. It also seems to take the body a good while to fully adapt to a high fat zero carb diet, but once it does, calories (or something) start to count again. Others that have tired a meat and fat centric diet for an exteneded peroid of time have had almost the exact same results. Thoughts? BTW, I'm 58, 6'1'' and weigh 160.

Kurt To Lex

Hello Lex and welcome

"I have been eating one single meal per day of 1 ½ to 2 lbs of raw grass fed beef, bison, elk, or deer for several years now."

Go here for my thoughts on Raw:

http://www.paleonu.com/panu-weblog/2009/8/16/raw-paleo-and-zero-carb-right-for-the-wrong-reasons.html

"First, I initially believed that this way of eating would keep blood glucose low. This seemed to be true in the beginning, but after 18 to 24 months, blood glucose started creeping up to about 100 mg/dl and it pretty much stays at that level all the time."

This sounds like physiologic insulin resistance. This is well described by Peter at hyperlipid - search his site for "physiologic insulin resistance". If you are VLC, fasting BG can be high as your muscles will reject glucose especially with morning hormonal changes - usually BG will drop later on - "area under the curve" should still be low for both BG and insulin. Have your fasting insulin level and your HBA1c levels checked - if these are good there is nothing to worry about.

"Second is the weight loss myth. I did initially loose lots of weight no matter how much I ate and independent of the fat/protein ratio of the food I ate. But then again after 18 to 24 months, I found I had to severely limit my food intake to keep my weight in check. I seem to do best when fat is between 60% and 70% of calories. At 80% of calories, I start to gain significant weight on the same amount of food and feel sluggish.

Short term results as far as weight and BG are concerned are far different than long term results. It also seems to take the body a good while to fully adapt to a high fat zero carb diet, but once it does, calories (or something) start to count again. Others that have tired a meat and fat centric diet for an exteneded peroid of time have had almost the exact same results. Thoughts? BTW, I'm 58, 6'1'' and weigh 160."

The very high protein intake of all-meat diets is often not considered. I have never heard of this phenomenon (starting to gain weight again) with lower protein intakes a la Optimal Diet (Kwasniewski) or PaNu which is similar in emphasizing fat over protein. If you are at 40% protein, up to 3/4 of that is being converted to glucose which requires insulin to handle - this is one reason PaNu is high animal fat and not "100% meat" - that may well be to much protein.

OTOH, you say you are 6'1" and weigh 160 -your BMI is 21.1 which is lower than mine at 21.8 ( 5'11'' and 156). Unless you have no muscles, you are pretty thin. If you are well muscled, and trying to keep your body fat percentage unnaturally low (below your set point) that would be another reason you have to consciously restrict your intake. Why are you picking a particular weight? When you get up to the new undesired heavier weight are you at a new equilibrium or do you continue to gain if eating ad lib? Trying to stay below your genetic setpoint will be difficult.

I have to say I have never seen the "calories start to count again" with my approach. Not saying it can't, just hasn't

My weight has been steady at 156 lbs for 18 months and never deviates more than a pound even if my caloric intake deviates by 20% or more. Carb intake 5% is the same weight for me as about 15% - if i went to 20-25% carbs i would probably add 2 or 3 lbs.

Lex to Kurt

I read Peter's blog on Physicological insulin resistance (thanks for pointing it out), and it seems FBG in the higer range is normal for VLC and ZC dietary protocols. Peter states his FBG is even higher than mine but his A1c is lower. I've only had one A1c test and that was this year. It came in at 6% which is at the very high end the medically 'acceptable" range. I've asked to have this test added to my annual blood tests so it will be interesting to see what it does over the long term.

As for my total consumption of food, I eat until I'm staisfied and just don't want any more. Most of the time I eat around 2 lbs of meat that is around 70% calories from fat. This works out to about 2,200 calories per day and 150g protein. If I'm physically working hard (digging trenches for srpinklers and clearing trash etc) I'll get hungry again and eat another pound or so (whatever it takes to fully satisfy my hunger) early in the evening, but this happens only a few times per month.

I assure you that the weight gain issue is real. As an experiment I spent 5 months eating a diet of 85%+ calories as fat. Again, the same 2 lbs per day and it was difficult eating that much. This provided about 125g protein and 3,500 calories per day. The first couple of weeks I lost weight but then slowly over a 2 month period I put on over 10 lbs and kept gaining. I finally cut my food intake down (which was more enjoyable as I didn't feel so stuffed), and the weight dropped off.

I use an FA73 commercial fat analyzer so I do know fairly accurately how much fat I'm truly eating.

I eat my meat raw becasue I prefer it that way. I have nothing against cooked meat and when eating out or with friends will gladly eat meat however they have prepared it. I ususally ask for it rare, but if it comes well done, so be it. Life is much to short to agonize over trivialities. I dropped all carbs as I either don't like them (most vegetabales) or they are sugars bombs (fruit). I dropped dairy years ago due to acne and other allergies, so it's pretty much just fatty red meat with the occasional fish or fowel when eating out and nothing better is available. I feel wonderful and enjoy my meals so have little incentive to change.

Wonderful blog,

Kurt to Lex

Thanks for sharing your experience here.

I hope you didn't think the new rant was directed at you - I have a had a few contacts with ZC and raw paleo and just wanted to let everyone know my editorial take on those concepts

I am glad you are not 100% raw meat out of dogma- it's a bit weird to mainstream society but so is my cream consumption. I have no issue with raw meat if you are confident of the source.

My vegetable consumption is pretty limited - mostly mushrooms and onions which I find I digest well and taste great. Too many tomatoes gives me some IBS symptoms but I eat a few anyway. Green beans are way too much fiber - I overcook them to a partially carmelized state - that helps a lot. All vegetables are used to soak up butter.

I am concerned about your HBA1c. ALthough a level of 6.0 on the SAD would not be alarming, there is a big difference in risk between 5.0 and 6.0. 6.0 means you have a bit of excess glycosylation going on in your body more than we would expect on VLC.

Here is what Kwasnwiewski and probably Peter would say: When you are VLC, your enzymatic protein needs are much lower than on the SAD. 10% of calories perhaps. In your case, you are really eating closer 15-20% carbs.

That HBA1c level indicates 1) excess glucose production via gluconeogenesis, 2) elevated insulin resistance (beyond physiologic)or 3) inadequate insulin production. How long have you been on the diet? Were you obese with signs of metabolic syndrome before?

Some folks with type II DM or who had some type I DM going on would have impaired insulin secretion ability and would be healthier on VLC but still might need to limit glucose more. I recommend Bernstein's book ( see my book section). Optimal diet ratios of 85% fat, 5% carbs and 10% protein (like Peter's) might work better in that case.

I would suggest seeing a physician and gettiing fasting insulin and c-peptide levels drawn to sort out what your insulin levels are doing.

To my recollection, Peter's BG is high in the AM but lower postprandially -being in the 100s around the clock is not what I would expect as normal physiology on VLC or ZC

Lex To Kurt

You asked how long I have been on an all meat diet and if I previously had any metebolic symdrome.

I've been on all meat for almost 4 years now. When I started I weighed 215 (40" waist), and blood pressure was slowly climbing (145/95), FBG was beginning to climb (120+), cholesterol was climbing (250+), triglycerides were high (500), and I had little energy as well as suffering from 3 or 4 killer migraine headaches per month.

Today my weight is stable between 160 and165 (33" wasit), blood pressure has dropped to 110/65, FBG runs right at 100 and is stable, choelsterol is now 175, riglycerides are 50, and I feel great. I haven't had a migrane headache in over 3 years now which is worth the price of admission by itself.

I was diagnosed with BPH about 5 years ago and take 2mg Doxazosen per day. It hasn't gotten any worse and I haven't had to increase the meds in 5 years so though VLC hasn't cured it, my doctor is surprised that it hasn't gotten worse. If you have any advice on this I'll try anything to get off this last medication.

Per your suggestion, I'll try dropping protein intake to 10% of calories while keeping calorie intake in the 2,500 range and see what happens to FBG. This would provide 60 to 65 grams of protein and about 250 grams of fat. Does this seem reasonable? Protein intake seems rather low.

Kurt to Lex

Sounds good. I would still suspect, especially given the signs of metabolic syndrome you started with, that your pancreas may be a little burnt out or that you are still a little pathologically insulin resistant. In either case, limiting your protein might help - see if your post prandial BG comes down.

I still suggest fasting insulin and c-peptide levels working with your local MD - remember I can't give medical advice, just general nutrition ideas.

I'll have to look into the Doxazosen for other metabolic affects.

Lex to Kurt

I’ve been reading Peter’s blog and found the “What I eat” post. The example he gave showed 245g fat, 65g protein, and 44g carbohydrate for a typical day. I’m assuming that all 44g carbohydrate turn into glucose, and if 60% of the protein is converted to glucose as well, this would be a total potential glucose load of 83g per day.

For a typical day I eat about 150g of fat, 150g of protein, and 0g of carbohydrate. Using the same 60% conversion rate of protein to glucose I get a potential glucose load of 90g per day. This isn’t a whole lot different that what Peter gets on a typical day (assuming my assumptions are reasonable), yet his A1c is 5% and mine is 6%. Also my BG usually varies between 95 and 105 and Peter says his is usually varies between 100 and 120.

Any thoughts on why my A1c is significantly higher than Peter’s while potential glucose is similar and my average BG tends to be lower? Very puzzling.

Peter also states he eats 'just enough carbs to stay out of ketosis'. Why is staying out of ketosis important? I'm constatly spilling a very small amount of ketones (between Zero and Trace) all the time. Is this a problem?

Kurt to Lex

If you are ZC, you can assume that you are ketoadapted and efficient at burning fatty acids and ketone bodies maximally by now. Your glucose requirement (unavoidable) is therefore about 50 g/day. Note that I am using 2000 kcal /day as an assumption. You need 50g or 10% carbs however you get them.

If you are 60/40 fat/pro that is a bit more than 125 g fat and 200 g protein. Your glucose requirement comes first, even at the expense of using your own muscles, so if your conversion efficiency is 60% going from protein to glu, it will take 50g /0.60 or 80 g of the protein to supply your glucose needs. This leaves 120 g of Protein. As you are not a grain eating carb burner, your protein needs are rather modest, and about .8 g/kg bodyweight should do it. For 70 kg, you only need 56 g of protein. The remaining 64 g can be burned or turned into glu or fatty acids.

So your 40% pro and 0% carbs is not necessarily creating less of an insulin requirement than 10% protein and 10% carbs. This may not take the form of an insulin spike as you are not eating carbs, but it still takes insulin to handle the glucose and even the protein

This is not exact, but the metabolic priorities are the point. If you eat no carbs, the protein you eat is converted to glucose at 60% efficiency until you have your minimum glu required. The excess protein can then be burned or turned into fatty acids or ketone bodies, but not as efficiently as stored or dietary TGs.

The point of Kwasneiwski's optimal diet is that you need the glucose anyway so why not eat it straight away at approximately the 50 g level? This is similar to what Bernstein recommends and it is what I recommend with my evolutionarily inspired reasoning. They all end up at about the same place. If you think of metabolism first, and if you believe in low insulin levels but also requiring your body to do less metabolic work, you will:

1) provide the phylogenetically oldest fuel first in as small an amount possible that allows you not to have to create it from protein inefficiently - approx 50g or 10% carbs. Eating much more than this amount is in no way necessary and a lot more is definitely bad but there is no reason to think there is any benefit to eating less than 10%.

2) Eat only the protein you really need as the rest is wasted or inefficiently converted to fat that you could more efficiently process if you just ate it directly.

3) Eat everything else as high quality animal fats - especially as saturated fats - the diesel fuel of the typical mammalian cell. No insulin response, few liver enzymes required, no inefficient conversions.

I'll cover ketosis and what I know about it in an upcoming post

Lex to Kurt

Thanks so much for the detailed reponse. It answers the protein part of my initial question but then brings up another protein related question.

Most people are under the impression, which your post seems to support, that the body only converts protein to glucose if glucose is needed. This would make your statement that I may as well eat the 50 grams of needed glucose as carbs to meet this need. My experiments don't support this view. My experience has been that 60% or so of ALL dietary protein seems to be converted to glucose. Eating 50 grams of carbs just adds an additional glucose load to the 60% of protein that will be converted to glucose anyway.

I've come to this conclusion through shredding my fingers with hundreds of BG tests after eating meals with and without carbs. My sore fingers say that carbs just add an additional higher spike in glucose early on, and gluconeogensis from protein continues over the longer term at about the same rate as without the carbs. As you say it certainly is not exact but from my personal excperince and that of several others that I know that are attempting to control BG and insulin through diet, our tests seem to support that protein will be converted to glucose at some rate regardless of the body's 'need' (as represnted by a relatively high initial before meal BG levels) for glucose.

I would also point out that in a previous post I noted that my FBG runs around 100 and if it were true that gluconeogenisis only ocurrs if the body needs glucose, then my eating a zero carb meal should not raise BG (but it does), and one would expect that FBG would hover around the lower levels of the "normal" range, only being produced when needed. My experience and even Peter's blog show that FBG hovers around the upper levels of the normal range - even for mince - when most of the source for glucose comes from protein.

All my evidence shows that some portion of all dietary protein is converted to glucose and it would seem that adding an additional 50g or so of carbs to purposely fill the body's glucose requirement just adds to the glucose load as long as protein is sufficient to meet the body's protein needs In other words, if 60% of all protein eaten is converted to glucose and my body needs about 56g of protein, then I would have to consume a minimum of about 125g of dietary protein to fulfill the body's protein requirements and this amount would also fulfill the the body's glucose requirements and any carbs eaten would just add more (unneeded?) glucose. (This is exactly what I'm doing now and my average BG is running high) To consume less protein than 125g would leave less than 56g after gluconeogenisis and muscle wasting and other signs of protein deficiency could result.

If my tests (run over weeks and months) are anywhere near the mark, then it would seem that eating any additional carbs is not needed at all because by fulfilling the body's minimum protein requirement we assure that the glucose requriement is met as well by the conversion of some percentage (60%?) of all protein eaten.

I understand that my reasoning is rather simplistic and the body's functions complex, but my limited knowledge of what's truly going on leaves me at a loss to explain my test resutls in any other way. Hope you can make things more clear with better information.

Kurt to Lex

"My experience has been that 60% or so of ALL dietary protein seems to be converted to glucose. Eating 50 grams of carbs just adds an additional glucose load to the 60% of protein that will be converted to glucose anyway."

I don't agree that this is what is happening. You cannot conclude that 60% of all protein gets converted to glucose. That may be close to the efficiency of conversion but all protein does not get converted.

"I've come to this conclusion through shredding my fingers with hundreds of BG tests after eating meals with and without carbs. My sore fingers say that carbs just add an additional higher spike in glucose early on, and gluconeogensis from protein continues over the longer term at about the same rate as without the carbs. As you say it certainly is not exact but from my personal excperince and that of several others that I know that are attempting to control BG and insulin through diet, our tests seem to support that protein will be converted to glucose at some rate regardless of the body's 'need' (as represnted by a relatively high initial before meal BG levels) for glucose."

It sounds like you are conflating glucose blood levels with your "glucose accounting". Glucose levels rising or falling depends on insulin, glucagon, cortisol, epinephrine, etc. It may be true that there is always *some* conversion, but I cannot imagine any mechanism that would preserve a stochiometric ratio of .60 no matter what the protien consumption. Are you claiming that eating 10 grams of protein a day only nets you 4 g amino acids? I certainly do not think that is correct.

Insulin or glucose "spikes" do not kill you - chronically elevated levels do that.

KEY CONCEPT: You have a reservoir of 300 g glucose in the form of glycogen in your liver. Glucose can go sky high in an instant without any glucose or protein consumption whatsoever, even in the fasting state with whole body glucose deficit running for many hours at a time. Transient changes in insulin resistance, including hormone mediated effects on the various glucose transporter molecules, can raise blood sugar and so can increases in glycolysis in the liver. It is erroneous to infer what is happening to consumed macronutrients based on blood glucose measurements.

"I would also point out that in a previous post I noted that my FBG runs around 100 and if it were true that gluconeogenisis only ocurrs if the body needs glucose, then my eating a zero carb meal should not raise BG (but it does),"

The glucose may coming from the glycogen stored in your liver as well, depending on when you are measuring it. Again, you cannot say that there is gluconeogenesis just becuase your BG rises. The serum level depends on uptake being enhanced or inhibited as well as glucose being released from pre-existing sotrage.

"and one would expect that FBG would hover around the lower levels of the "normal" range, only being produced when needed. My experience and even Peter's blog show that FBG hovers around the upper levels of the normal range - even for mince - when most of the source for glucose comes from protein."

As far as health effects, remember that BG can be pretty stable in someone with good insulin sensitivity but eating the SAD - they will still have bad effects from high insulin levels required to handle the glucose.

On the other hand, if you still have poor insulin sensitivity, where insulin does not work as well as normal, you coudl eat VLC and have good average insulin levels, but still have lability of BG, just like a diabetic.

If I recall correctly, Peter's BG is high only when fasting and the drops substantially after meals. This woudl have to be the case, as his HBA1 C is low and the only way to have it low is if the AUC (area under the curve) for BG is low. If your levels are still in the 100s after meals and between meals, and not just in the AM, that may explain your HBA1c -that is why I speculated you may have some IR going on.

"All my evidence shows that some portion of all dietary protein is converted to glucose and it would seem that adding an additional 50g or so of carbs to purposely fill the body's glucose requirement just adds to the glucose load as long as protein is sufficient to meet the body's protein needs In other words, if 60% of all protein eaten is converted to glucose and my body needs about 56g of protein, then I would have to consume a minimum of about 125g of dietary protein to fulfill the body's protein requirements and this amount would also fulfill the the body's glucose requirements and any carbs eaten would just add more (unneeded?) glucose. (This is exactly what I'm doing now and my average BG is running high) To consume less protein than 125g would leave less than 56g after gluconeogenisis and muscle wasting and other signs of protein deficiency could result."

I think there is no advantage to purposely converting your extra protein to glucose, and again I think your interpretation of this 60% conversion ratio being static is incorrect.

Read Bernstein's Diabetes Solution. If his protocol of 50g carbs divided into two or three meals works for someone with type II diabetes and even for someone with type I (Bernstein himself) who must take their own insulin because they cannot make it, then there is absolutely no reason it cannot work for anyone.

The "zero carb" faith is simply not based on science. There is no scientific reason to treat carbohydrate like an intolerable poison.

"If my tests (run over weeks and months) are anywhere near the mark, then it would seem that eating any additional carbs is not needed at all because by fulfilling the body's minimum protein requirement we assure that the glucose requriement is met as well by the conversion of some percentage (60%?) of all protein eaten."

Not needed to sustain life but in no way does that mean 50g a day would harm you.

"I understand that my reasoning is rather simplistic and the body's functions complex, but my limited knowledge of what's truly going on leaves me at a loss to explain my test resutls in any other way. Hope you can make things more clear with better information."

Lex, sincere seekers such as yourself keep me on my toes and motivate me to teach what I know. You have challenged me to plan some more posts on these issues, especially carb ratios, gluconeogenesis and ketosis. Thanks

Lex to Kurt

Thanks so much for the encouragement and your thoughts. It is clear you spent a good bit of time on your repsonse and have given me much to think about.

Rest assured that I'm not a Zero Carb zellot. I don't believe that a zero carb diet is superior to one that includes plant based carbs - only that this approach has worked well for me for the past 4 years or so. When asked my opinion, I always say that there is no 'magic' in an all meat or ZC diet, and believe that most people would be better served with a VLC diet that includes a piece of fruit or a small salad each day. I ate this way myself for a couple of years before trying the zero carb route, and gained most of the health benefits I currently enjoy from eating that way. I may return to this protocol in the future if I find that an all meat diet is no longer meeting my needs. At this point, however, I’m pleased with the simplicity and incremental improvements I’ve gained eating an all raw red meat diet and so will stick with it for the foreseeable future. (until you convince me that there is a better way!)

I certainly am open to adding a few carbs back into my diet if there are sound reasons to do so. I look forward to your future posts on this subject. I'm extremely interested in learning more about the pros and cons of constant mild ketosis, and pros and cons of depending on gluconeogenisis as the body's primary source for glucose.

It will take me a while to digest what you've put in your current reply so for now I'll sit back and try to absorb what you've said.

Thanks for taking so much time to answer my questions,

Kurt to Lex

I know you are not a zealot as I've read some of your very thoughtful journal. As the blog proprieter, my responses are often directed to the general audience as well as to the questioner.

An all raw meat diet fits as well in the PaNu tent as well as my VLC dairy-and-eggs diet. Stephan's soak-your brown-rice animal products heavy Weston Price diet fits too. So does Peter's Kwasniewski type Optimal Diet.

Rest assured I am not trying to convince you to add back carbs, just that it might not harm you to do so. Big difference.

I think in the short term it may be easier to get folks on board by telling them what to eat, but it is more scientific, and will ultimately be more socially durable and more inclusive to focus on avoiding the agents of neolithic disease.

Paleolithic man had a varied diet so modern man should be able to as well.

PaNu is a big tent. Only the neolithic agents are barred entry with a palm thrust forward.

Finally, let me say I respect what you have done for low-carb eating and I welcome your participation in my blog.