The FastDay Forum

No, I don't think so just that low GL is the way to go. There is some scientific evidence that long term low carbing or frequent fasting (ADF) can deposit fats in the heart muscle and cause stiffness and left ventricular dysfunction. So as with everything...moderation is needed! My guess is that the Mediterranean diet as expounded in the 2 day diet is best wrt fast and carb balance.

Really Caroline? That's worrying (there's always another bit of scientific breaking news to raise anxiety levels don't you think?) - I've been low carbing, or trying to, for a number of years and was contemplating ADF or regular 3/4 day fasts ala Dr Longo, but maybe I should think again.

Perhaps the best way forward is to take a considered approach to the whole thing - I don't think it's possible to control for all variables - and deal with the most pressing concerns as a priority. For me, that's chronic arthritis (inflammation), obesity and diabetes on the horizon, not to mention a host of other, unseen and often imagined, nasties going on inside!

What does 'wrt' mean (sorry to be dim)?

Thanks as always for your informative posts.

Marlene

[carorees]

wrt = with respect to (sorry for my laziness!)

There have been a couple of studies in rats on long term low carb diets and on ADF that showed accumulation of trigycerides in the heart muscle. Now ADF for a rat is a pretty big intervention as 24 hours without food is a lot bigger proportion of their life than 24 hours for us! The low carb diets involved high fat too.

As you say, a considered approach. I think the maxim "moderation in all things" applies equally well to fasting and low carbs as to every other walk of life. Also, to my mind, going fanatical about carbs, fasting or whatever is not healthy mentally either. It's no good living longer if you are not enjoying it!

I tried Vegan for a few months and it was very hard to maintain- for me anyway. We eat out a fair bit and uk restaurants do not cater for vegans. The veggie option usually involves creamy sauces or mountains of cheese. It involved a fair bit of prep work to do at home and as my husband and son refused to join in I was doing two meals at every mealtime. I just folded, but I learned huge amounts of very interesting nutritional stuff from people like this guy. His website is fab for nutrition geeks, like you say.

[carorees]

This recently published paper looks at the effect of a high (ish) and low protein diet on weight loss and of maintenance of fat free mass.

A [protein intake] of 0.8 g /kg/day is sufficient for body weight management, whereas a [protein intake] of 1.2 g/kg/day is necessary for preservation of REE and a stronger initial sparing effect of FFM and lowering of DBP.

I wonder how we might translate that to 5:2 practice? 1.2 g/kg on fast days and 0.8 g/kg on non-fast days? Or 1.2 g/kg throughout the weight loss period and lowering to 0.8 g/kg when in maintenance in order to gain the mooted IGF-1 benefits?

Can you put that in English for us non-scientific types? Please?

The problem most common to these studies is that when they reduce or increase protein, they are also studying a reduction or increase in something else, whether it is carbs, fat, or calories. It has a trickle down effect, and they can't possibly tell which had the effect.

Personally, I think getting to a point where I can tell what my body is asking for is the answer to it all. Luckily doing 5:2 is getting me to a point where I can. Using my non-fasting days to practice eating only when I am physically hungry, eating only what I really want to eat, eating it mindfully, and stopping when I am no longer hungry.

Very interesting but I don't understand all the abbreviations used?

I've noticed that I crave less protein since I started fasting - and I prefer fish and poultry rather than red meat - I used to be a steak and burger fan.....

[carorees]

Sorry I didn't expand the abbreviations but this IS in the nerdy section folks!

REE = resting energy expenditure (when you're asleep/lying in bed)
FFM = fat free mass (everything in your body that isn't fat)
DBP = diastolic blood pressure (the bottom number when you hear blood pressure quoted)

Translation: a slightly higher protein diet gave better protection against loss of muscle/water etc during weight loss than a lower protein diet, resulted in a lesser slow down in resting energy expenditure and gave better improvements in diastolic blood pressure. (NB, applies to this study, not necessarily generalisable as deMuralist points out).

Varady's studies that show no loss of LBM used protein at 15% of calorie intake.

ie on 400 cals protein is 60 cals or 15 grams.

I added these abbreviations to the wiki.

0.8 - 1.2 g/kg is 3.2 - 4.8 calories per day per kg of body weight which in my opinion is way too much on fasting days - I'm not convinced going over 35% of calories is useful, necessary or even achieves anything other than excess protein being used as fuel.

A 100 kg person eating 1.2 g/kg would need 120g of protein which is 480 cals which might be ok as part of a 1600-2000 calorie intake but looks a bit odd in a 500-600 calorie intake on a fast day.

So Phil is your view that we can eat a lot less than 0.8g/kg on a fast day (as many of us do, probably) without any ill effects. Isn't this study saying different?

I think when we discussed this before I came away with the impression that since body tissue is being recycled internally all the time it really wasn't a big deal if one lost a bit of FFM on a fast day (because of inadequate protein intake) and then rebuilt it afterwards, in fact it might even be a good thing. Not sure whether that is scientific, though...

Indeed, I have the 30g/day maximum stuck in my head and most of the trials are under that - especially the ADF ones - including the ones that showed preservation of FFM.

I'll read the full paper later when I get the 2nd computer back on line after its service (it knows some useful passwords). In particular I'll be looking closely at the energy prediction methods used.

Thanks Phil will be interesting to hear what you make of it when you have read the whole paper. (I presume you don't have access to it, Caroline?)

I had eggs for supper just in case...

[carorees]

No, no secret passwords here . For my work, if I need a paywalled paper I get my clients to supply it .