87 replies to this topic

[Bron]

Google "calorie restriction" and you'll find plenty of studies that support that. If you want to reduce inflammation and improve your health nothing comes close to CR.

That's a very strong claim, and I can't find anything supporting it.

It's an easy claim to make. Google it.

If you'd like to run a little experiment try this.

Step 1) Check your blood pressure and write it down.
Step 2) Eat 1500 calories per day for a week.
Step 3) Check your blood pressure again.

Compare your results and decide for yourself.

My blood pressure was exactly the same before I started CR, two months into CR, and now almost 5 months into CR (just had it taken again the other day), 120/80. Every once and a while it is 118, or 121. Most of the time, 120/80 however.

However I do have low CRP levels. Sadly, I cannot tell you this is directly attributable to CR or not.

I am 25 years old. I doubt I will ever stop CR. Although, with what my exercise routine used to be, I would never be able to do that on a CR diet.

Edited by Bron, 01 March 2013 - 11:35 PM.

[xEva]

Bron, your blood pressure is fine, which is expected in your age. There is no need to change it. DR01D is ~20 years older and had highish blood pressure before he started CR.

Lower protein 2 days a week does mean lower total protein consumption for the week. Theoretically speaking lower overall protein consumption means lower IGF-1.

I believe there is a certain distinct level of protein consumption, above which IGF-1 will be upregulated and below which it will be low. Otherwise it's like argueing that fasting blood glucose of 90 is better than 100 -- yes sure it is better, still both are considered too high for optimal health. How much protein do you comsume?

In the BBC program Michael Mosely fasted for 3 days and it significantly lowered his IGF-1. I wish the show was still on YouTube so I could check his results but I think he said his IGF-1 dropped by half or a third or something along those lines.

Yes, I remember that he fasted for 3 days. I don't quite recall which parameter he measured and how much exactly it dropped (and promptly went back to baseline when he resumed eating). I remember very well though that his was a 3-day water only fast, while for you 'fast' means eating twice a day instead of 3.

A human goes into ketosis on starvation on the 3rd day of a water-only fast (some do it sooner). This involves significant hormonal and metabolic changes from a mere CR state. These are very different things and are best not to be confused.

Edited by xEva, 02 March 2013 - 12:36 AM.

[DR01D]

xEVA

I think we are talking about two different things.

I'm interested in...

A) Calorie restriction
B) Reducing or eliminating the processed foods in my diet
C) Eating less protein
D) Using a narrow feeding window as often as possible (6 hours per day would be perfect)
E) Exercise and activity
F) Strength training

I'm doing that to increase the odds that I can live a healthy, long life to 100. To me it's about healthy living, not increasing my maximum potential lifespan to 110, 120+.

I think you are interested CR as a way to increase maximum, potential lifespan. That's not what I'm talking about.

Edited by DR01D, 02 March 2013 - 02:26 AM.

[Bron]

Bron, your blood pressure is fine, which is expected in your age. There is no need to change it. DR01D is ~20 years older and had highish blood pressure before he started CR.

Makes sense, will only see a drop to healthy levels from unhealthy levels? Thanks.

Also explains why I haven't seen other drops as well like hemoglobin A1c: 4.8

Only thing is my cholesterol stayed exactly the same as well LDL122, HDL 33, trigycerides 153, total 186. I was hoping to see improvement.

I did see a large drop in total testosterone 334 ng/dl. That was more than halved from 700. Doctor was worried but since I still have the same sexual appetite and energy levels he said I should be fine since it is still technically in a "healthy range". Maybe I should look more into it. Sorry for derailing at all but we are talking CR.

Weight loss has been safe, average about a 1lb a week.

Edited by Bron, 02 March 2013 - 03:40 AM.

[xEva]

DR01Dm I am not trying to sway you into anything. I am only pointing out common misconceptions about CR and expectations people have about it based on rodents studies. This is a widespread problem.

For example, the study I talked about above, where they fasted mice for 48h in order to induce autophagy in neurons, was titled Short-term fasting induces profound neuronal autophagy. And that's how it was reported in popular press. This is very misleading. 48h may be short in human terms, but it is a serious fast for mice, who by then were in deep ketosis having lost 20% of body weight. They had to fast them for 48h, because 24h, while being plenty to induce autophagy in hepatocytes, was not quite enough for neurons.

Not to go too far, today Reason posted a similarly misleading headline about CR. People, including many researchers, overlook the fact that CR in rodents, as it is commonly implemented, involves real fasting, while CR in humans does not. What many call a fast here has nothing to do with what rodents, with their super-fast metabolic rate undergo.

[DR01D]

DR01Dm I am not trying to sway you into anything.

If you posted a study that showed that any of my A through F were unhealthy that might dissuade me.

But I'm not trying to use any of those activities to put my body in a "special" biological state. Well... unless "healthy" is considered a special state.

If I live as long and as healthy as Jack Lalanne that will be good enough for me.

[nowayout]

I did see a large drop in total testosterone 334 ng/dl. That was more than halved from 700. Doctor was worried but since I still have the same sexual appetite and energy levels he said I should be fine since it is still technically in a "healthy range". Maybe I should look more into it.

There are a number of studies associating lower testosterone to all kinds of chronic disorders and diseases of aging, as well as earlier mortality. There are studies that indicate that this link may be causal in many cases, so I would be worried about this if I were you.

You should worry about the following: Aspects of metabolism that deteriorate with low testosterone and improve with T supplementation are inflammation markers, lipid profile, insulin sensitivity and glycemic control, bone metabolism, lean body mass to fat ratio, mood.

http://www.ncbi.nlm....pubmed/21753068

Onset of effects of testosterone treatment and time span until maximum effects are achieved.

Saad F, Aversa A, Isidori AM, Zafalon L, Zitzmann M, Gooren L.

Source

Scientific Affairs Men's Healthcare, BU General Medicine/Men's Healthcare, Bayer Pharma AG, D-13342 Berlin, Germany. farid.saad@bayer.com

Abstract


OBJECTIVE:

Testosterone has a spectrum of effects on the male organism. This review attempts to determine, from published studies, the time-course of the effects induced by testosterone replacement therapy from their first manifestation until maximum effects are attained.
DESIGN:

Literature data on testosterone replacement.
RESULTS:

Effects on sexual interest appear after 3 weeks plateauing at 6 weeks, with no further increments expected beyond. Changes in erections/ejaculations may require up to 6 months. Effects on quality of life manifest within 3-4 weeks, but maximum benefits take longer. Effects on depressive mood become detectable after 3-6 weeks with a maximum after 18-30 weeks. Effects on erythropoiesis are evident at 3 months, peaking at 9-12 months. Prostate-specific antigen and volume rise, marginally, plateauing at 12 months; further increase should be related to aging rather than therapy. Effects on lipids appear after 4 weeks, maximal after 6-12 months. Insulin sensitivity may improve within few days, but effects on glycemic control become evident only after 3-12 months. Changes in fat mass, lean body mass, and muscle strength occur within 12-16 weeks, stabilize at 6-12 months, but can marginally continue over years. Effects on inflammation occur within 3-12 weeks. Effects on bone are detectable already after 6 months while continuing at least for 3 years.
CONCLUSION:

The time-course of the spectrum of effects of testosterone shows considerable variation, probably related to pharmacodynamics of the testosterone preparation. Genomic and non-genomic effects, androgen receptor polymorphism and intracellular steroid metabolism further contribute to such diversity.

http://www.ncbi.nlm....JE110221f03.jpg

http://www.ncbi.nlm....JE110221f02.jpg

Edited by viveutvivas, 02 March 2013 - 02:31 PM.

[DR01D]

You should worry about the following: Aspects of metabolism that deteriorate with low testosterone and improve with T supplementation are inflammation markers, lipid profile, insulin sensitivity and glycemic control, bone metabolism, lean body mass to fat ratio, mood.

I wouldn't totally discount that. It could be that low testosterone is always unhealthy. But it's also possible that if a body is running efficiently it doesn't need to produce as much testosterone to get the same result.

For example...

Group 1) Low testosterone because of health problems
Group 2) Low testosterone because a healthy, lean body needs less testosterone

A lot of things could work like that.

Group 1) Short stature because of health problems during youth
Group 2) Short stature because of natural heredity

Group 1 is sickly but group 2 is healthy even though they share the same trait. Superficially it might be hard to tell the two groups apart.

Edited by DR01D, 02 March 2013 - 08:33 PM.

[Bron]

I did see a large drop in total testosterone 334 ng/dl. That was more than halved from 700. Doctor was worried but since I still have the same sexual appetite and energy levels he said I should be fine since it is still technically in a "healthy range". Maybe I should look more into it.

There are a number of studies associating lower testosterone to all kinds of chronic disorders and diseases of aging, as well as earlier mortality. There are studies that indicate that this link may be causal in many cases, so I would be worried about this if I were you.

You should worry about the following: Aspects of metabolism that deteriorate with low testosterone and improve with T supplementation are inflammation markers, lipid profile, insulin sensitivity and glycemic control, bone metabolism, lean body mass to fat ratio, mood.

http://www.ncbi.nlm....pubmed/21753068

Onset of effects of testosterone treatment and time span until maximum effects are achieved.

Saad F, Aversa A, Isidori AM, Zafalon L, Zitzmann M, Gooren L.

Source

Scientific Affairs Men's Healthcare, BU General Medicine/Men's Healthcare, Bayer Pharma AG, D-13342 Berlin, Germany. farid.saad@bayer.com

Abstract


OBJECTIVE:

Testosterone has a spectrum of effects on the male organism. This review attempts to determine, from published studies, the time-course of the effects induced by testosterone replacement therapy from their first manifestation until maximum effects are attained.
DESIGN:

Literature data on testosterone replacement.
RESULTS:

Effects on sexual interest appear after 3 weeks plateauing at 6 weeks, with no further increments expected beyond. Changes in erections/ejaculations may require up to 6 months. Effects on quality of life manifest within 3-4 weeks, but maximum benefits take longer. Effects on depressive mood become detectable after 3-6 weeks with a maximum after 18-30 weeks. Effects on erythropoiesis are evident at 3 months, peaking at 9-12 months. Prostate-specific antigen and volume rise, marginally, plateauing at 12 months; further increase should be related to aging rather than therapy. Effects on lipids appear after 4 weeks, maximal after 6-12 months. Insulin sensitivity may improve within few days, but effects on glycemic control become evident only after 3-12 months. Changes in fat mass, lean body mass, and muscle strength occur within 12-16 weeks, stabilize at 6-12 months, but can marginally continue over years. Effects on inflammation occur within 3-12 weeks. Effects on bone are detectable already after 6 months while continuing at least for 3 years.
CONCLUSION:

The time-course of the spectrum of effects of testosterone shows considerable variation, probably related to pharmacodynamics of the testosterone preparation. Genomic and non-genomic effects, androgen receptor polymorphism and intracellular steroid metabolism further contribute to such diversity.

http://www.ncbi.nlm....JE110221f03.jpg

http://www.ncbi.nlm....JE110221f02.jpg

Thanks for the information. I already made an appointment with an endocrinologist. And you are right it is not something to be taken lightly.

My estradiol levels seem fine: 34 pg/ml

Edited by Bron, 03 March 2013 - 07:05 PM.

[Chupo]

In the BBC program Michael Mosely fasted for 3 days and it significantly lowered his IGF-1. I wish the show was still on YouTube so I could check his results but I think he said his IGF-1 dropped by half or a third or something along those lines.

It's on Vimeo. He cut his IGF-1 in half by calorie-restricting twice a week.

http://vimeo.com/54089463

[DR01D]

It's on Vimeo. He cut his IGF-1 in half by calorie-restricting twice a week.

Thanks so much for posting that! Best video ever.

This quote is from the video.

Total body fat in Joseph is 11.5%

Joseph Cordell demolished Dr. Mosely on all of the tests but his body fat is 11.5% and he eats 1950 calories per day. It shows that you don't have to go crazy with CR to see major improvements in your health.

Edited by DR01D, 04 March 2013 - 08:02 PM.

[scottknl]

Luckily Dr. Mosely seems to be a serial CR experimenter who produces CR related material every few years. So we should expect another item from him in 2015 or so when he once again rejects CR as being too difficult and takes up another dietary regime that he thinks is easier and almost as effective. It'll be fun to see if he's aging too much or not.

[Chupo]

It's on Vimeo. He cut his IGF-1 in half by calorie-restricting twice a week.

Thanks so much for posting that! Best video ever.

This quote is from the video.

Total body fat in Joseph is 11.5%

Joseph Cordell demolished Dr. Mosely on all of the tests but his body fat is 11.5% and he eats 1950 calories per day. It shows that you don't have to go crazy with CR to see major improvements in your health.

No problem. It's a good video. I've downloaded it this time just in case it goes missing from Vimeo too.

It's amazing how much Dr. Mosely improved by doing so little. I think it goes to show how much constant overenergy people on western diets are getting. Their systems never get a rest. I'm not so sure the results would have been so drastic if he'd just averaged the restriction of calories out over the week. I think the break periods are important, especially in the context of the western diet. He very well may have increased his longevity by not dying prematurely. That is huge because most people can't CR long term but they probably could handle a couple days a week.

[DR01D]

It's amazing how much Dr. Mosely improved by doing so little. I think it goes to show how much constant overenergy people on western diets are getting. Their systems never get a rest. I'm not so sure the results would have been so drastic if he'd just averaged the restriction of calories out over the week. I think the break periods are important, especially in the context of the western diet. He very well may have increased his longevity by not dying prematurely. That is huge because most people can't CR long term but they probably could handle a couple days a week.

I think you're right. The digestive system needs to rest. I can't find it now but I remember a study on sciencedaily that found that mice lived significantly longer if they narrowed their daily eating window even on the same number of calories.

I think one of the reasons CR is hard for most people is their diet. Modern, processed food digests fast. Over time I switched to a diet consisting of mostly unprocessed food plus I eat piles of raw vegetables. It helped me stay full for a longer period of time and that made CR a lot easier. Also when I get hungry I no longer have that famished feeling I used to get when I ate regular food. I just get a little bit hungry.

I don't mind being a little bit hungry in between meals and before I go to bed. Regular people are conditioned to snack at the first sign of hunger. Maybe that's why Dr. Mosely had a hard time sticking to CR.

Edited by DR01D, 05 March 2013 - 01:37 PM.

[xEva]

... The digestive system needs to rest. I can't find it now but I remember a study on sciencedaily that found that mice lived significantly longer if they narrowed their daily eating window even on the same number of calories.

It's worth remembering that when mice "narrow their daily eating window", it means they are actually fasting, i.e. go into ketosis of starvation in between meals

I think one of the reasons CR is hard for most people is their diet. Modern, processed food digests fast. Over time I switched to a diet consisting of mostly unprocessed food plus I eat piles of raw vegetables. It helped me stay full for a longer period of time and that made CR a lot easier. Also when I get hungry I no longer have that famished feeling I used to get when I ate regular food. I just get a little bit hungry.

I don't mind being a little bit hungry in between meals and before I go to bed. Regular people are conditioned to snack at the first sign of hunger. Maybe that's why Dr. Mosely had a hard time sticking to CR.

I think that when people start CR it involves certain epigenetic changes, and those are always hard to induce and it's also hard to live through such an induction. It's called adaptation and it gets harder with age. It's always easier to follow the same routine and avoid change.

[nhenderson]

Interesting article: For CR to work seems to require that the subjects be active. (In a fruit fly model) This might color one's veiw of the primate studies. Frankly, I had discounted inactivity as an explaination for those results! (And as has been shown or at least correlated, sedentary behavior increases all cause mortality in humans.)

http://www.buckinsti...ary-restriction

[nowayout]

I don't mind being a little bit hungry in between meals and before I go to bed. Regular people are conditioned to snack at the first sign of hunger.

I would go even further and say that regular people are conditioned to snack or eat meals in the absence of hunger, as well as to continue eating while satiated.

Edited by viveutvivas, 08 March 2013 - 01:08 AM.

[Hebbeh]

I don't mind being a little bit hungry in between meals and before I go to bed. Regular people are conditioned to snack at the first sign of hunger.

I would go even further and say that regular people are conditioned to snack or eat meals in the absence of hunger, as well as to continue eating while satiated.

Recreational eating is the number 1 cause of obesity in the USA. Going out to eat is not because you're hungry but because it's a fun social activity to gorge on high calorie and highly unhealthy foods on a daily basis with your friends...and is usually combined with unhealthy excessive drinking...and followed by sedentary activities such as a movie with more snacks....followed by more drinks after the movie. And if not going out...lets binge in front of the TV....the number 1 pastime in the USA...TV which always includes constant never ending high calorie snacks.

I don't own a TV and don't go out to eat unless it is truly a special occasion or I absolutely have to....and all my friends and acquaintances know this....and believe I'm deprived...and probably eccentric at the least....because nobody else lives this way.

[Audioque]

Doesn't matter to me. I'm on this for increased youth span and to remain as disease and disability free as long as possible. When I hit a certain age (70? 90?), I will eat my way out.

[DR01D]

Interesting article: For CR to work seems to require that the subjects be active. (In a fruit fly model) This might color one's veiw of the primate studies. Frankly, I had discounted inactivity as an explaination for those results! (And as has been shown or at least correlated, sedentary behavior increases all cause mortality in humans.)

http://www.buckinsti...ary-restriction

Awesome study link!!! Thanks for posting it.

Being sedentary is unnatural to humans and it doesn't surprise me that it might nullify many of the benefits of CR.

I've said it before and I'll say it again...

1500 calories combined with a sedentary lifestyle is probably not as healthy as 1800 calories and an active lifestyle.

Edited by DR01D, 08 March 2013 - 04:03 AM.

[xEva]

I don't want to rain on your parade DR01D, but the key players in the article were glucagon and enhanced fatty acid metabolism in muscle, which is what happens in humans during fasting (as in starvation, not eating twice a day). Glucagon is released when liver glycogen is depleted. That's what initiates the ketotic state and enhanced fatty acid metabolism. You need to either fast or run marathons to achieve this.

[DR01D]

This is from the article.

“This study establishes a link between DR-mediated metabolic activity in muscle, increased movement and the benefits derived from restricting nutrients,” he said, adding that flies on DR who could not move or had inhibited fat metabolism in their muscle did not exhibit an extended lifespan. “Our work argues that simply restricting nutrients without physical activity may not be beneficial in humans,”

“Our data suggests that DR may induce changes in muscle similar to those observed under endurance exercise and that molecules like AKH could serve as potential mimetics for DR that enhance activity and healthspan,” said Katewa.

I don't want to rain on your parade DR01D, but the key players in the article were glucagon and enhanced fatty acid metabolism in muscle, which is what happens in humans during fasting (as in starvation, not eating twice a day). Glucagon is released when liver glycogen is depleted. That's what initiates the ketotic state and enhanced fatty acid metabolism. You need to either fast or run marathons to achieve this.

The scientists didn't write that calorie restricted humans needed to participate in extreme (probably harmful) exercise such as running marathons. They found that CR and endurance exercise triggered similar changes in muscle. Lack of physical activity short circuited this system.

Edited by DR01D, 08 March 2013 - 01:39 PM.

[James Cain]

I don't want to rain on your parade DR01D, but the key players in the article were glucagon and enhanced fatty acid metabolism in muscle, which is what happens in humans during fasting (as in starvation, not eating twice a day). Glucagon is released when liver glycogen is depleted. That's what initiates the ketotic state and enhanced fatty acid metabolism. You need to either fast or run marathons to achieve this.

Actually, even moderate exercise increases glucagon and fatty acid metabolism, and can induce acute ketogenesis depending.

http://books.google....epage&q&f=false

Edited by James Cain, 08 March 2013 - 01:38 PM.

[DR01D]

I don't want to rain on your parade DR01D, but the key players in the article were glucagon and enhanced fatty acid metabolism in muscle, which is what happens in humans during fasting (as in starvation, not eating twice a day). Glucagon is released when liver glycogen is depleted. That's what initiates the ketotic state and enhanced fatty acid metabolism. You need to either fast or run marathons to achieve this.

Actually, even moderate exercise increases glucagon and fatty acid metabolism, and can induce acute ketogenesis depending.

http://books.google....epage&q&f=false

Wow!!! Another awesome link, thanks for posting that.

Edited by DR01D, 08 March 2013 - 01:41 PM.

[xEva]

This is from the article.

[...]

The scientists didn't write that calorie restricted humans needed to participate in extreme (probably harmful) exercise such as running marathons. They found that CR and endurance exercise triggered similar changes in muscle. Lack of physical activity short circuited this system.

DR01D, the article was about fruit flies, not humans.



James Cain, I only got to see page 148 (chapter 6) and there it plainly says that "Exercise in the fasted state is characterized by increase or no detectable change in arterial glucagon." and that "Catecholamines, glucagon and cortisol are generally stimulated sinergistically by exercise in the presence of hypoglycimia of hypoxia." Which is about what I was saying, i.e. one needs to be either already fasting or in a seriously fasted state (like Jack Lalane used to work out in the morning, after an overnight fast and not eat until couple of hours after his workout). The other alternative is to be on a ketogenic diet, which a priori gives one an enhanced fatty acid metabolism.

And thank you for posting this link indeed. I remember years ago (the year when Jack Lalane died) I got into bickering with guys here who insisted that one should eat a bit of carbs before a workout, while I insisted that it's best to exercise on absolutely empty stomach. This book confirmed what I knew intuitively. Page 148: "The absorption of nutrients from the gastrointestinal tract alters many of the hormonal responses to exercise."

[anagram]

Can someone share some information regarding changes in hormonal synthesis after fasting?
After reading about 21-amino steroids, I have become affixed to the idea that there are chemical alterations in steroid synthesis after CR, which lead to health promoting effects.

21-amino steroids are modifications of steroids giving them very potent anti apoptic properties and prevent hypoxia related alterations of organs and cells.
http://www.nature.co...r19962642a.html
http://www.ncbi.nlm....les/PMC1571640/
I understand that these compounds are unlikely to be produced in vivo, but I believe that they're properties are a proof of concept. perhaps there is an alteration of steroid synthesis during CR, which leads to the endogenous production of physiologically active compounds.

Another idea floating around in my head is the idea that the physical compression that exercise and CR does to cells has health promoting effects.
http://newscenter.be...hen-compressed/
There is way to many possibilities of action for this effect, I cannot think of a reason why this would happen, can you?

Oh I almost forgot... is it possible that a cells conservation of energy which would be caused by CR, might cause a down regulation of receptors? I read somewhere that cells which did not respond as much as normal cells to the insults of chemical's typically live longer, which makes me believe that by blocking receptor protein synthesis in turn decreases the metabolic changes associated, thus leading to lower metabolism and less oxidative injury. --- this is far fetched , but can anyone think of how this might exist in vivo or at all?

Edited by anagram, 09 March 2013 - 05:28 PM.

[James Cain]

James Cain, I only got to see page 148 (chapter 6) and there it plainly says that "Exercise in the fasted state is characterized by increase or no detectable change in arterial glucagon." and that "Catecholamines, glucagon and cortisol are generally stimulated sinergistically by exercise in the presence of hypoglycimia of hypoxia." Which is about what I was saying, i.e. one needs to be either already fasting or in a seriously fasted state.

I'm sorry you can't see more of the pages. Page 150 has more information to explain your selected quote.

Like insulin, glucagon is carried by pancreatic venous drainage to the hepatic portal vein that perfuses the liver. Perfusing theliver with pancreatic venous drainage is efficient for regulation of glucose output from the liver because it permits glucagon to have rapid and potent effects on the liver without the need for excessive glucagon secretion and high arterial levels. This is an efficient arrangement physiologically, but it adds a degree of difficulty to the assessment of changes in glucagon secretion. This is because increases in glucagon at the liver (that is, in the portal venous blood) are not strictly reflected by concentrations in the systemic circulation from which blood is sampled. Increases in arterial and peripheral venous glucagon levels are often small or undetectable in humans after short- or moderate-duration exercise (less than about 45 minutes). A decrease in peripheral glucagon levels may even occur during high-intensity exercise. Exercise longer than 1 hour generally results in an unequivocal increase. However, studies in the laboratory with animals with indwelling arterial and portal vein catheters show that arterial glucagon levels greatly underestimate the levels to which the liver is exposed. Studies in humans suggest that increases in glucagon secretion are approximately fourfold during moderate exercise. The reason that increases in glucagon release and portal vein glucagon do not translate into proportional increases in arterial concentrations is an increased hepatic extraction of glucagon by the liver.

Additionally, neither fasting nor a ketogenic diet in a healthy individual will result in hypoglycemia during exercise, though if one were to experience hypoglycemia then they would respond with increased catecholamines, glucagon, and cortisol to raise blood glucose. Hypoglycemia (more related to ATP/ADP and NAD+/NADH) and hypoxia occur to much smaller, subclinical degrees at the cellular level during exercise, and these chemically drive much of the metabolic effects of, and adaptations to, exercise. I'm not saying you're wrong, just that it's much more nuanced than you've made it seem. Biology is rarely as black and white as people generally make it out to be.

[xEva]

Thank you James for your explanation. I thought hypoglycemia in that context simply meant low glucose, but not necessarily pathologically low. Low as in 'I have not eaten for a while' as opposed to much higher levels seen after a meal, especially if it consisted of simple carbs, like guys used to advocate just before a workout.

Also, reading the passage you quoted I was thinking the following: I've always exercised in a fasted state, since I was a kid or a high school star sprinter, all the way to when working out was simply part of my lifestyle. So I'm pretty sure that I have experienced glucagon release during exercise countless times. And yet having glucagon released while going into the ketosis of starvation is different. Maybe because I am not necessarily moving right at that moment?

What I'm trying to say is that you're right about metabolic nuances. Exercising in a fed state is very different from exercising in a fasted state, and different still from fasting (as in starvation) and a ketogenic diet. And yet people tend to lump all these very different states together and treat them as if they are almost the same, because, in theory at least, they seem to have many similarities (pathways, hormones, active receptors, etc).

Edited by xEva, 12 March 2013 - 11:34 PM.