Comments on: Running from the proof: correlation does not mean causation

By: David MacPhail

David MacPhail — Fri, 22 Aug 2008 22:09:15 +0000

ME: I guess I need to do a post on this at some point because it�s a question I get constantly. The short answer is that insulin doesn�t operate in a vacuum. It operates in tandem with its counterregulatory hormone glucagon (also produced in the pancreas). It�s not the amounts of either that count, but the ratio of the two.

I think it would be very helpful if you did a post on this with perhaps some sort of graph showing how the ratio of insulin to glucagon is affected by protein and carbohydrate. To the best of my knowledge, fat does not provoke any insulin or glucagon response which is why I eat fat if I get hungry between meals (which only seems to happen if I don’t consume enough fat with a meal).

If you read books on the glycemic index the authors typically stress that protein should always be consumed with carbohydrate. I think it probable that they know this will favourably improve the insulin to glucagon ratio. The lack of general knowledge of the existence of an insulin/glucagon ratio has been used by some anti low carb authors to argue in favour of a high carbohydrate diet by stating that protein is worse than carbohydrate because of the amount of insulin secreted. Either these authors are abysmally ignorant or they are engaging in deception.

The idea that protein should be consumed with carbohydrate is idiotic or. at best, demonstrates a total lack of understanding of the insulin to glucagon ratio. Both protein and carbohydrate increase insulin. Protein increases glucagon while carbohyhdrate decreases glucagon. With a mixed meal of protein and carbohydrate the insulin levels soar and the glucagon level falls, giving a greatly increased insulin to glucagon ratio, which is unfavorable to health.

By: Francis St-Pierre

Francis St-Pierre — Wed, 20 Aug 2008 20:27:48 +0000

“We might have studies showing that men who have mistresses (and keep them well occupied) live longer than men who don’t. So therefore having a mistress leads to longevity…?”

Well well, what do we have here?

Want to live a little longer? Get a second wife. New research suggests that men from polygamous cultures outlive those from monogamous ones.

After accounting for socioeconomic differences, men aged over 60 from 140 countries that practice polygamy to varying degrees lived on average 12% longer than men from 49 mostly monogamous nations, says Virpi Lummaa, an ecologist at the University of Sheffield, UK.

http://www.newscientist.com/article/dn14564-polygamy-is-the-key-to-a-long-life.html?DCMP=ILC-hmts&nsref=news6_head_dn14564

I love these kinds of studies. And believe them whether the data is valid or not.

By: kevinoneall

kevinoneall — Wed, 20 Aug 2008 15:38:17 +0000

Years of attempting to run while in ketosis told me I can’t do it. I’ve done marathons, double marathons and one 24 hour race while in ketosis. In each case I was reduced to a walk after four or five hours. My understanding of the Krebs cycle is that a small amount of glucose is needed. Hence, the “Fat burns in a carb flame” idea. In ketosis, the body catabolizes muscle protein to make the necessary sugar to feed into the Krebs cycle. These days I f0llow a low carb diet but in the days leading up to a race I fill up on carbs to reload my muscles with glycogen. I tried eating fat while running but that never worked. I tried drinking olive oil while running: big mistake. I tried eating peanut butter while running: bigger mistake. For marathon-length runs I rely on whatever carbs are available at the aid stations, usually M&Ms or cookies. For 50 milers or longer, I add some sort of protein.

By: ItsTheWooo

ItsTheWooo — Tue, 19 Aug 2008 19:28:42 +0000

My father held jobs that had him walk often. Ever since he was a young man, he was employed in a position where he had to stand and walk, often with heavy loads. At 60, the osteoarthritis in his right hip became so severe he could only limp to get around. The hip was unstable and he would often fall. He had no choice but a hip replacement.
Ironically, at the time his OA was diagnosed I started having some right hip discomfort myself. I was 23 at the time. At first I thought it was psychological. Now it it’s like 2 years later and I still have it (whereas my father’s hip pain has been gone the past year, because of his hip replacement).
I do enjoy walking frequently, I avoid public transportation or cars as much as I can get away with. I partially attribute this to my frequent walking habit. I am not able to walk as much as I would like to because it invariably triggers the pain, sometimes it gets so bad that the whole leg is in pain, even down to the knee. It seems to be getting worse, lately my lower back has been a bit stiff and sore.

I don’t think walking is the only reason I have this problem now, at a relatively young age. I know there are other factors, but it is *certainly* true that all of my walking/standing was the trigger. The pain goes away if I am sedentary.

By: steve

steve — Tue, 19 Aug 2008 19:10:22 +0000

Dr. M:

What is even more fascinating is that even among the low carb advocates there is not agreement. Some say lean meats(lower sat fat intake), and others say no worry to eat hi fat meats,etc. Does say something about state of nutritional science: There are no easy answers.

Hey Steve–

It’s important that you realize that it is the unenlightened low-carb advocates that recommend the avoidance of high-fat meats.

Cheers–

MRE

By: Dave

Dave — Tue, 19 Aug 2008 15:47:11 +0000

I’m curious as to what people think about this quote from the Phinney paper (http://www.nutritionandmetabolism.com/content/1/1/2):

“Therapeutic use of ketogenic diets should not require constraint of most forms of physical labor or recreational activity, with the one caveat that anaerobic (ie, weight lifting or sprint) performance is limited by the low muscle glycogen levels induced by a ketogenic diet, and this would strongly discourage its use under most conditions of competitive athletics.”

Is it known that muscle glycogen is systematically lower on a ketogenic diet? Or can gluconeogenesis fill up glycogen stores, given a long enough adaptation period?

I think that people on low-carb ketogenic diets can sustain a certain amount of intense anaerobic activity, but they will ultimately outrun their ability to make enough glucose via gluconeogenesis to keep up.

By: Judy B.

Judy B. — Tue, 19 Aug 2008 15:14:51 +0000

Totally OT but very funny!

http://www.pharmalot.com/2008/08/theres-no-business-like-the-healthcare-business/

Very funny indeed. Thanks for sending.

By: p.rooney

p.rooney — Tue, 19 Aug 2008 14:08:29 +0000

Long time lurker, big time fan of both you and Mr. Taubes. Thanks for giving me the science to defend myself against my “health care” providers and my foolish marathoning friends. Dragged in my copy of “Good Calories, Bad Calories” this morning to share with a co-worker. Can only try.

Thanks for being out there for us non-scientists!

I’m glad you’ve been lurking and enjoying.

Best–

MRE

By: Mike G

Mike G — Tue, 19 Aug 2008 13:04:06 +0000

Dr Eades: Very good article by Steve Phinney (above). This info has been available from experts such as Tim Noakes, MD for many years but Phinney recaps it concisely. Anyone interested in vigorous aerobic exercise and LC should read it. It�s a very persistent MYTH that running requires carbs.

By: Ebby

Ebby — Mon, 18 Aug 2008 22:03:30 +0000

A little off this specific running topic, but please comment on the insulin index. The only list that I can find online is:
http://www.mendosa.com/insulin_index.htm
I understand that high blood sugar levels are bad, high chronic insulin levels are bad, but help me understand why beef or cheese elicits a greater insulin response than pasta, and if this is true, is their (beef, cheese) insulin response a concern? Has there been more work on the insulin index? I notice that pure fat foods aren’t on the list. Is the list an “area under the curve vs peak” argument that we’re seeing with regard to the numbers?

I guess I need to do a post on this at some point because it’s a question I get constantly. The short answer is that insulin doesn’t operate in a vacuum. It operates in tandem with its counterregulatory hormone glucagon (also produced in the pancreas). It’s not the amounts of either that count, but the ratio of the two. Proteins stimulate an insulin response but they also stimulate a glucagon response. The ratio of the two doesn’t really change. Carbohydrate intake stimulates a large insulin response and a negative glucagon response, making the ratio skyrocket.