The FastDay Forum

Firstly I would ignore the nay sayers - the proof is in the pudding. Secondly I have seen this "diet" described as a "strategy" for weight management which I think is a much better way to describe it. Thirdly I don't think the yahoos on the other site have any clue what they are talking about. I have a PhD in Biochemistry and to me it makes perfect sense. It is true that if you starve yourself your body starts to burn muscle preferentially and decreases you basal metabolic rate. But that is not what is happening here - it is caloric restriction on 2 days of the week which will lead to about 1lb lost a week (and the math makes sense because you are short just over 3000 calories for the week which equates to about 1lb). You won't see that every week because we have varying amounts of food in our digestive tract and depending on what we eat (or other considerations like menstrual cycle for women) we can retain significant additional fluids.

Pip - what you are describing sounds like hypoglycemia (low blood sugar) - have you had blood work done recently?

Cheers to all.

Allan.

[carorees]

Allan and Pip, the problem is metabolic inflexibility. Some people's bodies really resist changing fuels, usually the result of too high insulin, and particularly in obesity. This results in low blood sugar and the symptoms Pip is describing. A low carb diet before and during the fast may help. My worst fasts have been after having a high carb diet the night before. If you search for metabolic inflexibility in the nerdy section you'll find some info with links to published papers. It will resolve, but it takes a while for the body to activate the fat burning pathways.

HTH

Yes agreed - insulin resistance caused by obesity leads to high circulating insulin levels.

Back to the original topic I found this paper on pubmed - while it is ADF and not 5:2 I think it shows the benefits of this dieting concept. I also pasted the abstract of the paper below.

http://www.ncbi.nlm.nih.gov/pubmed/23612508

Eur J Clin Nutr. 2013 Apr 24. doi: 10.1038/ejcn.2013.83. [Epub ahead of print]
Alternate day fasting increases LDL particle size independently of dietary fat content in obese humans.
Klempel MC, Kroeger CM, Varady KA.
Source

Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA.
Abstract

Alternate day fasting (ADF) with a low-fat (LF) diet increases low-density lipoprotein (LDL) particle size. Whether these beneficial effects can be reproduced by a high-fat (HF) ADF diet is unclear. This study compared an ADF-HF to an ADF-LF diet on plasma lipids, LDL size and high-density lipoprotein (HDL) size. Thirty-five obese subjects were randomized to an ADF-HF or ADF-LF diet for 10 weeks. Body weight decreased (P<0.0001) by 4.3±1.0 kg (4.8±1.1%) and 3.7±0.7 kg (4.2±0.8%) in the ADF-HF and ADF-LF group, respectively. LDL cholesterol was reduced (P<0.0001) by 19±8 mg/dl (18±5%) by ADF-HF and 28±7 mg/dl (25±3%) by ADF-LF. LDL particle size increased (P<0.005) by 3±1 Å in both groups. The proportion of small LDL particles decreased (P<0.005) by 8±2% and 11±3% in the ADF-HF and ADF-LF groups, respectively. HDL cholesterol and HDL size remained unchanged. Thus, our results suggest that the ADF-HF diet is equally as effective as the ADF-LF diet in improving LDL particle size and distribution.European Journal of Clinical Nutrition advance online publication, 24 April 2013; doi:10.1038/ejcn.2013.83.

[carorees]

Hi Allan, yes the 5:2 diet is largely based on the studies from Krista Varady. If you would like a summary of all the fasting studies we've found, please look at PhilT's thread in the nerdy section. It has details of this and the other human studies. The thread is a sticky at the top of the nerdy stuff. (It'll save you hours on pubmed!)

Trouble is, most of the skeptics are not willing/able to look at the original studies and form their opinion based on evidence

[carorees]

And here's the link to that thread: viewtopic.php?f=10&t=669

Thanks Carorees,

I will take a look.

I realize a lot of the 5:2 diet was based on her work. The study I posted was only published online yesterday so if it is in the current library you guys are fast.

I am on Pubmed every day anyway. We are trying to develop a stem cell treatment for insulin dependent diabetes (mainly Type I to start with).

Cheers,

Allan.

I find that on a fast day, if I go into a group environment I can't focus on what people are saying, or respond intelligently, and all I want to do is curl up and sleep. Fasting makes me very anti-social.

Pip you are such a tonic! No feel-good nonsense here. So downbeat it makes me smile, sorry. Fortunately you can't punch me.

Allan and Pip, the problem is metabolic inflexibility. Some people's bodies really resist changing fuels, usually the result of too high insulin, and particularly in obesity. This results in low blood sugar and the symptoms Pip is describing. A low carb diet before and during the fast may help. My worst fasts have been after having a high carb diet the night before. If you search for metabolic inflexibility in the nerdy section you'll find some info with links to published papers. It will resolve, but it takes a while for the body to activate the fat burning pathways.

HTH

Thank you! That's very interesting (and comforting) to hear!

*goes off to do a search*

[carorees]

Allan: Oh sorry my mistake, it is a new study...I didn't check it properly. She had already published on high fat and low fat feed day results with ADF and I seem to remember on particle size too, but not high/low fat and particle size together till now! I'm sure Phil will add this one to the spreadsheet soon!

I would just say one thing: if the "eat less, exercise more" regime would have worked we wouldn't have an epidemic of obesity

Didn't cavemen eat this way?? They really didn't get a choice, in when they ate, they ate when it was caught, so yes, they had many a day of restricted calories and days of plenty. There were no overweight cavemen.

Didn't cavemen eat this way?? They really didn't get a choice, in when they ate, they ate when it was caught, so yes, they had many a day of restricted calories and days of plenty. There were no overweight cavemen.

Maybe. But the evolutionary argument can be made to fit all sorts of strange diets. Even this one.

Didn't cavemen eat this way?? They really didn't get a choice, in when they ate, they ate when it was caught, so yes, they had many a day of restricted calories and days of plenty. There were no overweight cavemen.

We have no evidence of this though do we???

You have fat seals/squirrels/lions/polar bears at different times of the year and different times in the "rainy season/drought" so why not fat cave people?

But surely that is the point? We evolve to burn both eaten carbs and stored fat so we don't die as soon as the fridge is empty.

The last thirty years though have seen a huge change in the way we all live.

Go back to the 1970's and treats like Pop, a pint, a decent joint, were all the preserve of Christmas, as my Dad is fond of saying "it is like Christmas every day" now. That is why we get Fat........

Joint as in Meat, not the other you Hendrix fans!

Agreed. If fasting is so dangerous. How come everyone that practices Ramadan isn't malnourished etc then! A whole population of people would survey show some signs after 100s of years.

Ramadan is a massive pig out party in the dark hours, malnutrition is not on the agenda.

Ramadan is a massive pig out party in the dark hours, malnutrition is not on the agenda.

Nor is pig, actually...