Insulin Growth Factor 1

I saw the same program Jo and rather than do the fasting method realised I was already effectively doing the calorie restriction method by being on around 1900 calories / day on a low carb diet. Consequently I never tried the fasting method that many others have.

As I understood it the aim is to suppress your production of IGF-1 because if you do your body enters a repair mode rather than a growth mode were cells are trashed and replaced. There is mounting evidence that people who put their bodies into repair mode live longer regardless of other health factors in their lives.

For IGF-1 to get produced (the thing you want to avoid) requires that your body has a supply of something called Growth Hormone (GH) and insulin. Your body needs both present to produce IGF-1. Consequently if you limit your insulin production through either calorie restriction or a low carb diet or through fasting then you will end up producing less IGF-1. Obviously probably the best method of limiting IGF-1 production is a full on Ketogenic diet.

Carbohydrate restriction will actually promote the production of Growth Hormone which in turn promotes a process called FFA. FFA is the process that drives your energy requirements from ketones rather than glucose by burning your fat cells which is why low carb and ketogenic diets get you to lose weight. Driving your energy requirements from ketone production is perfectly safe and shouldn't be confused with ketoacidosis which is a dangerous condition that needs treating immediately.

Downsides of surpressing IGF_1 appear to be that your body takes longer to repair tissue damage which is why ketogenic diets are sometimes not recommended to athletes with injuries.

An interesting book that goes into the mechanics further.

"The Ketogenic Diet: A Complete Guide for the Dieter and Practitioner" which is a pretty good guide to the pros and cons of a Ketogenic diet but written a few years ago. You can read it online here.

http://books.google.co.uk/books?id=...0CFMQ6AEwBQ#v=onepage&q=IGF-1 ketosis&f=false

One disadvantage of the fasting method in my mind was if you ate loads on certain days and then fasted on others unless to carb restricted on the non fasting days you could end up with a very spikey BG profile and there is evidence that people with stable profiles do better than those on spikey profiles even if the spikey person ends up with a lower hBA1c than the level person (obviously within sensible limits)

I also thought it sounded like the same benefits would apply to insulin using diabetics as carb reduction / calorie restriction reduces the amount of insulin needed to be used and would therefore also supress IGF-1 in insulin dependent people.

Defren said:

The point of this post is to seek out other anecdotal evidence of calorie restriction/fasting by others.

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DAVID FROST: Well you do look like Peter Pan and is it, do you think, since it's not nip and tuck is it, is it swimming, is it tennis, is it diet, you've been on a diet 35 years?

CLIFF RICHARD: Yeah well an eating regime more than a diet.

DAVID FROST: Yes.

CLIFF RICHARD: I mean I try not to eat more than one meal a day and I've stuck by that pretty, pretty religiously right the way through and I don't see myself as the Peter Pan of pop anymore, I keep saying the Rip Van Winkle of rock, but Peter Pan of pop was a great pleasure to hear people call me that originally, but once I hit 40, then 50 and now 60 it's really a bit of a pressure.

Defren said:

In the documentary 'eat, fast, live longer' Michael Mosely discussed GF1 as part of, or maybe the cause of aging. When I watched the documentary I was struck by the fact that many diseases are caused by a diet that promotes GF1. As Mr. Mosely put it, our bodies go into 'go-go' mode, so have no time to heal and repair. By fasting or calorie restriction we take our foot off the accelerator and put our body into repair mode. While we are in repair mode, our levels of GF1 are reduced, allowing our bodies chance to heal and repair. People with Laron syndrome naturally have low levels of GF1 and seem totally resistant to things like diabetes and cancer, no matter their lifestyle.

Many people believe that calorie restriction/fasting is bad for us. I am not one of those people, having done the Newcastle diet, and 5:2 fasting and still here to tell the tale. However, most (but not all) experiments have been done using laboratory animals, usually mice/rats. One human story that really stands out is the gentleman Mr. Mosely spoke to during 'eat, fast, live longer'. The gentleman was over 100 and had become the oldest person to complete the London marathon. Not only did he have that amazing achievement under his belt, he also takes no medication and has never had surgery. His secret? Very small (child size) portions of food, and a very simple Punjab diet.

The point of this post is to seek out other anecdotal evidence of calorie restriction/fasting by others. I have read a lot on the subject, and fully admit it makes my head hurt. The technical medical terms are difficult to understand. It is only after really trying hard to get to grips with this, am I now convinced beyond doubt calorie restriction/fasting do effect GF1 in a beneficial way. I am deciding (with input from my family) if dropping calories from my daily goal will be more beneficial for me, that 5:2 fasting. It is not a decision that should be made lightly in my opinion, and so the more opinions the better.

I realize I need to find a diet that will work for me that treats my diabetes first, my curiosity secondary. Daily reducing calories I could do reasonably easily, but is it right? This is a study done using people:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2673798/

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On the other hand

and to take a point or two from the above study which I thought underpinned one of the studies Mr Mosely undertook (his four day fast) "two long-term CR studies (1 and 6 years) showing that severe CR without malnutrition did not change IGF-1 and IGF-1 : IGFBP-3 ratio levels in humans."

It was my understanding that film suggests that when the body was deprived of all nutrition (which could be thought of as malnutrition in some sense)- then not just the go go turns off but the survival function takes over and in that state or process, dna is repaired and new brain cells manufactured - this was not however a continuing state as some time after the 4 day fast Mr Mosley's IGF-1 levels returned to their 'before fast levels' (but then he also went back to carbs too)

However the very great Linus Pauling advocated a very severe calorie restricted diet, which he used himself to manage 'Brights Disease' for 53 years before dying at 93 of cancer.

For me I felt that the four day fast (though possibly more difficult to incorporate into a lifestyle than 5:2) was probably more consistent with our pre-westernised eating patterns. I felt that it was a more consistent to suggest that as hunter gatherers it might be a more likely scenario to suppose that we would run out of food for a couple of days (until a new kill was made) rather than to be persistently without or on reduced supply as with the 5:2 regime.

But I look forward to many others input and shall follow this thread with interest

Gilly x

I think any woman considering fasting should read Stefani Ruper on the subject. Most of the studies done have been about men (as usual!):

http://www.paleoforwomen.com/category/fasting/

I'm finding the whole subject of nutritional ketosis fascinating lately. I've lost most of the weight I want to lose and I've got my blood glucose mostly under control, but the whole subject is fascinating, especially hearing people like Dr Phinney and other low carb doctors and writers like Nora Gedgaudas who've been living in ketosis for years and rave about the benefits.

If you haven't already seen the articles, Jimmy Moore's experiment is interesting stuff:

http://livinlavidalowcarb.com/blog/jimm ... 1-30/14409

I figure we're half way there since we've already got the glucometers. What are ketone strip prices like in the UK? Here in OZ they're not funded, but cost $8.95 for 10 strips, which is nothing like what it costs in the US.

I'm reading Phinney & Volek's book on my Kindle, even though it's mostly aimed at athletic performance, but it covers the mechanics of reaching/monitoring/maintaining nutritional ketosis. Still pondering whether I can go that low carb or not...

One human story that really stands out is the gentleman Mr. Mosely spoke to during 'eat, fast, live longer'. The gentleman was over 100 and had become the oldest person to complete the London marathon. Not only did he have that amazing achievement under his belt, he also takes no medication and has never had surgery. His secret? Very small (child size) portions of food, and a very simple Punjab diet.

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Yeah, I noticed that too. I'm not quite sure how the BBC can employ this many people this ignorant of statistics*.

It's a classical example of "hypothesis suggested by the data" aka Texas sharpshooter fallacy - the guy's diet and survival is completely irrelevant unless they had set out to specifically monitor *him* 100 years ago. Odds are that he's just lucky to have the right genes and to have avoided accidents that would have resulted in him needing surgery.

* This sadly appears to be fairly epidemic - for example, the back of "29 billion reasons to lie about cholesterol" contains an error blatantly obvious to anyone familiar with Simpson's paradox

If you haven't already read Nora Gedgaudas' 'Primal Body, Primal Mind', I'd definitely suggest it for you. She goes into a heap of longevity information/research in the book, the subtitle of which is "Beyond the Paleo Diet for Total Health and a Longer Life".

http://www.amazon.com/Primal-Body-Mind- ... +gedgaudas