The FastDay Forum

[carorees]

I found a bit about metabolic inflexibility here :

Metabolic inflexibility refers to an organismal impairment in regulation, which manifests as the inability to appropriately shift fuel preference in the face of metabolic challenges, like fasting, exercise, a meal, or overfeeding. The inflexible state of metabolism results from a discordant attempt of numerous peripheral tissues to respond to changing fuel needs and nutrient availability, yielding little or no discernable response.

Thanks Caroline, I would appreciate seeing the article (you just posted while I was replying so I will have a look at the link - thanks). I just had a look through the nerd section but didn't find anything yet.

When I had it in the past I was over-exercising and eating little of anything but carbs (I was an idiot) and it has been a number of years since it was a problem. I know my insulin levels and everything else are fine as I have to have blood tests every 3-4 weeks until they work out what is wrong with my liver and they test for pretty much everything. I actually suspect the liver thing might have influenced this but it didn't even cross my mind prior to today that it might be an issue. Complex carbs sound like a good idea in the meantime.

Cheers.

Louise

Jemima - Thanks. I am going to hang in here, perhaps saving up for one meal rather than smaller meals during the fast day might work out better for me. That way I can ensure I cover the complex carbs for overnight.

The headache thing seems to be a phase, I certainly struggled a few fast days and once bad enough for pills and a lie down. I'm fortunate in having a flexible lifestyle where I can adjust my day to how I feel.

I also have cocoa or milk just before going to bed.

[carorees]

Yes, liver problems could well affect glucose homeostasis.

Do a pubmed search for metabolic flexibility...lots of good stuff!

Caroline - That is what I am currently doing. Although, I have to get on with my experiments so will have to do more at lunch time.

Still feeling shaky but headache has eased and am no longer dizzy/nauseous. Actually scared myself earlier.

I need to keep in mind that I am doing this for health benefits and not just weight loss, although I do hope that I can find a way to trigger the fat burning side. My bottom would certainly benefit if I do. Early days though and it will probably take a while to adapt to the regime.

[carorees]

It's tricky isn't it? For most people, their bodies give in and switch to fat burning and after a couple of fasts they have no problems.

It seems that the combination of fasting and exercise was perhaps too big a challenge for your body as both these trigger the metabolic switch to fat burning. Once you have regained your metabolic flexibility the combination should be no problem.

My reading of the literature suggests that women have a glycogen store in the region of 1000-2000 kcals. It is very variable. I suspect that the onset of hypoglycaemic symptoms in people starting fasting must relate to how long it takes for the glycogen stores to be depleted and of course it depends on what types of foods have been eaten in the day preceding the fast as well as during the fast and on how much exercise is taken. It seems that to enter ketosis one has to fast for quite a period, but if you are eating low carb and exercising you can enter ketosis earlier. I find it odd that people are experiencing symptoms earlier than one might expect. People doing fasting report not finding ketones in urine for 2 to 4 days after the start of the fast but perhaps that is because you start to turn to ketones for fuel before they appear in the urine. I guess the symptoms come when glycogen runs low and a need to mobilize fat occurs. Probably you don't completely deplete glycogen before starting on fat because of the need to have some glucose in the system for those cells that cannot utilize ketones.

So, anyway, in your case I think it worth not trying to force your body into ketosis until you can understand the role your liver problems might be playing. Alternatively, perhaps you could try low carbing for a couple of days before a fast and then plan not to exercise intensively during or immediately after the fast. Looking at the literature, it seems that the ability to make the metabolic switch is dependent on mitochondrial function in skeletal muscle. The HIIT protocol publicized by Dr M in his programme "The Truth about Exercise" or indeed any high intensity short duration exercise does increase mitochondria and should aid metabolic flexibility. Perhaps a tweak of your exercise regimen might help?

Hope my musings are of use!

BTW, what are you experimenting on? Hope its biology-related and my use of jargon is not causing you a problem! (My PhD was in immunology and allergy, but I have spent the past 23 years as a medical writer, now freelance which is why I can spend so long on the forum and browsing pubmed!)

Caroline,

Thanks for the info and yes, it helps. From the brief reading I have done, it also seems like the size of mitochondria in skeletal muscle indicates their ability to make the switch, which is interesting. I am a biological electron microscopist and tempted to put a sample of my own muscle in the microscope to look . Unfortunately ethics prevents it.

I run the electron microscopy lab and have numerous experiments going on at once, from eye tissues and cells, food products as part of the consultancy we run, viruses and viral infection of cells to my main research on the parasite that causes African sleeping sickness, T. brucei. I also teach microscopy users, run practicals on the microscopes for undergraduate students and supervise microscopy project students. I love the work.

I saw that you are a medical writer. Do you enjoy it?

Wow Caroline, I wondered how you came to be so erudite, I can't always follow your musing but find them interesting. I have time to browse because I am a retired lady who is nuts about computers and 5:2 dieting ever since I saw Horizon program. Also the exercise program. Lately changed from long time use of PCs to Apple. Hard learning curve. Thanks for all your input and Moogies.

I agree with Moogie. The morning after a fast day i never feel hungry until about 11.00am - then, when I do start eating, i get full really quickly.

This happened to me this morning.I broke my fast at 12.00 ravenously hungry, I cooked a huge english brekky.As soon as i sat down I knew I wasnt going to eat it. I left about 1/4 on my plate.I was really full.The dog will be gratefull.
Barbara

[carorees]

I saw that you are a medical writer. Do you enjoy it?

Oh, I love it. I get to see the results of all the latest research without having to put the hours in at the lab (let's face it the actual experimenting part is pretty dull, its the interpretation of results that's the fun bit...well it was for me). Or chase around for funding - very tedious. As I love English and Science it was the ideal job for me. (I really enjoyed writing up my PhD, which is unusual to say the least!)

Well this is interesting for me also ( wow who would have thought such clever people needed to loose weight! )

I have found today really weird, I fasted all day yesterday till 6pm, then had 400 or so calories. I felt a bit tired last night, and i was hungry all day.

Today I haven't eaten yet, and the hunger just goes in minutes.

I also have allot more energy, and believe it or not I had done the vacuuming, and the moping by 10a.m. and planted 7 trees by 12!!!! Now I would normally expect this to take me twice as long.

Now I am not sure how much is the diet and how much is not drinking the day before, but it is really strange how much better I feel today, to the extent that I really don't want to eat??????

Oh ok, I'll have a Pasty!

oooh, just read this thread and happily explains my symptoms after my first fast yesterday. I am full of energy, but have a headache. I too wasnt hungry first thing, but ate anyway, as I had a long walk to do as part of the school drop off. On Friday, I won't eat until I feel hungry and see if it helps, and ofcourse drink more water on my fast tomorrow. Off to take a paracetamol now.