The FastDay Forum

Thanks for all the excellent posts. Just finished 7th fast day and it is a little before 6am on Tuesday and I am feeling great.

My visceral fat has not changed much (again according to the scales). It has gone from 13%to 12% so I imagine any fat I have lost will be more subcutaneous.

On the protein intake I have not really measured it but I have always eaten a fairly high protein diet - tonight it is braised lamb shanks (nearly killed me to smell them slow cooking in the tagine last night) which we will have lots of veggies with and 1 slice of bread. So what has changed is I.we have really cut back on carbs - the only notable carbs we will have tonight is a small potato and the slice of bread so I guess most of my calories are coming from protein and fats.

As far as muscle goes I do a certain amount of weight training in the gym and also do around 4 vigorous yoga classes/week (I have been surprised at how strenuous these classes are on a number of muscles including the triceps deltoids and all major muscles in the legs. I also do one very hard spin class. So maybe muscle retention in partly diet and partly excercise. In fact I did a hard yoga class last night before dinner and will do another at 8:15am before I break the fast this morning - I am not sure if that is a bit over the top but I have felt OK doing it so no plan to change.

We are going to Australia for 2 weeks in 8 days and I don't realistically see us doing 5:2 down there so just trying to get as far as we can before the trip. Will pick up again when we get back but realistically I think we will take just a little step back

Thanks again for all the excellent posts.

Regarding which part of the body you lose fat from: another recent topic suggests that some people lose fat from around their waist preferentially and others don't. My (untested) explanation for this is that although most of us start off here somewhat apple-shaped because of over-eating, we will tend back to our natural body shapes. So if you are a natural pear, you will lose off your waist preferentially; if you are an apple, you may lose more subcutaneous fat first.

Allan, what about your protein intake on fast days? I don't think you get much protein from just smelling that wonderful tagine!

If the body is really short of protein (big if), I don't see how exercise is going to prevent loss of FFM; in fact because of the energy expenditure it might even increase the loss. It might affect where the loss is taken from though. Presumably the body will spare muscles that are being worked and will instead breakdown other FFM to access those essential amino acids - the gut has been suggested as a common source (info from Caroline in another topic, sorry I can't reference it now).

Taking a step back on the 5:2 road is allowed, Allan! I found it a bit frustrating though having to recover the ground I lost over Christmas (see my tracker) - I lost 6 1/2 weeks up and then down that ridge!

Dominic, I think I agree with your theory about where we all lose weight from. I am naturally a quite defined hourglass shape, and I've always tended to lose weight from my abdominal area first, and from limbs last. In support of your theory, since starting 5:2 three weeks ago, I've lost 7lbs, plus 3" from my waist.

Now, if anybody comes up with a diet that specifically guarantees loss of chunky arms, I'm afraid I'm defecting! Those of you who are apple-ish can at least take comfort from being able to wear sleeveless tops. I'm the only one of my circle of female friends who moans about her fat elbows

Thanks Dominic,

I worked out I took in about 23 grams of protein yesterday (most coming from 0 fat yogurt, half a hard boiled egg and chickpeas while sticking to my calorie restriction.

However I thought you broke down muscle during exercise and then built it back up. Today I will probably take in 100 grams of protein (will keep tally today).

I am not sure of the kinetics of exercise/muscle breakdown/dietary protein intake/muscle growth and repair. Does anyone know about that or have relevant references?

Thanks,

Allan.

[carorees]

You burn glycogen and/or fat stored in the muscle during exercise depending on the intensity. With muscle building exercise you damage the muscle creating micro-tears. Repair of these tears is what creates the increased bulk. Is that what you were thinking of? The breakdown of muscle during food shortage is due to the body needing a small amount of glucose to function and in the absence of food (and when glycogen is low) this glucose is provided by protein breakdown (gluconeogenesis). Growth hormone release limits the extent of protein breakdown by promoting fat release from fat stores for ketone production during fasting. Most body tissues can run off ketones or straight fats but a few need glucose. Fasting increases the amount of growth hormone produced compared with simple calorie restriction so this may be why fasting results in more fat lost compared with normal calorie restriction.

Check the manufacturer's instructions on the scale or get on their website or email them if you threw them away, but most of those kinds of scales are best used for weight first thing in the morning and best used for BF% in early evening just before you eat dinner.

I don't have one myself but we were shopping for one and that seemed to be the most common review online -- that they thought it was crap until they started following the instructions properly, and now it's the greatest thing since sliced bread!

Also it seems that manufacturers read reviews on places like Amazon and they seem to reward bad reviews with almost instant scale replacements, so don't be afraid to ask if your scale is defective. Even most people who gave bad reviews on the scales seemed to always rave about good customer service.

if anybody comes up with a diet that specifically guarantees loss of chunky arms, I'm afraid I'm defecting!

We're told that subcutaneous fat is not a problem health-wise, so you should be the happy one! Sheesh, some people are hard to please...

I think the chunky arms (and chunky thighs, if you have those too) will go in due course if you carry on losing for long enough, but maybe not before your hour-glass has been fully 'pinched'.

The breakdown of muscle during food shortage is due to the body needing a small amount of glucose to function

Sorry I am drifting off-topic here towards this one. I bow to your scientific knowledge Caroline but I thought it was about more than just glucose. What about those essential amino acids that the body needs and can't get from fat? It needs protein to obtain these, I thought, and if it is unable to get them from food it must break down body tissue to obtain them. There are none in body fat so that means loss of FFM.

So (I thought) however good your body is at fat burning you are going to need some protein intake to survive long-term, and even in the short-term if you are missing it your body will be 'flesh-eating' to get it. Sounds scary but as your body does this sort of recycling anyway it isn't such a problem (I think) provided your body gets the protein from food pretty soon so it can get back to rebuilding tissues.

(BTW in case anyone is tempted to start piling into protein after reading this, too much of it is also thought to be bad for us...)

[carorees]

I guess (some) amino acids are taken through autophagy? You may well be right, I am not sure about the relative contributions of protein breakdown to gluconeogenesis and to supplying amino acids. I'll need to investigate. I'm sorry, I was only considering the energy balance question (up to now).

Interestingly, obesity is associated with poor growth hormone response to fasting (likely due to insulin resistance causing high insulin levels) which might suggest that more of the weight loss would be FFM in obese/insulin resistant people until they become more metabolically flexible (aka fat adapted).

Interesting. I bought Omron body fat scales on 4March at which point my body fat was 40.9%, BMI 27.7, on 27th April by body fat was 41.0%, BMI 26.1. Weight loss in that period was 11lb, no change in fat %age. Not sure what to make of that.

I've had the same experience. I think the scales are not accurate. MM has said this too I believe.

[carorees]

Interesting. I bought Omron body fat scales on 4March at which point my body fat was 40.9%, BMI 27.7, on 27th April by body fat was 41.0%, BMI 26.1. Weight loss in that period was 11lb, no change in fat %age. Not sure what to make of that.

You're not looking at it the right way. I don't know what your weight is but let's imagine it was150lb when your fat percentage was 40.9. So150 x 40.9% = 61.3lb of fat. Then you lost 11lb in weight (so weight was then 139lb), and your fat percentage was 41%. 139 x 41% is 57lb of fat. So 61.3 - 57.0 = 4.3 lb of fat lost!

I am confused about the whole GH thing. In this 5:2 diet Dr M has made a significant point out of the fact that IGF-I levels go down on the diet and other diets like ADF. Having said that the main inducer of IGF-I synthesis is GH. GH is produced in the anterior pituitary and acts on GH receptors in the liver (and to a lesser extent other tissues like skeletal muscle)to cause the synthesis and secretion of IGF-I which can have major metabolic effects on muscle and long bone growth. As a side note and also mentioned in the Horizon program Laron dwarfs have a mutation in the GH receptor and therefore do not make IGF-I in response to GH (so treating Laron dwarfs with GH does not have any impact on long bone growth - instead they treat them with IGF-I - a major side effect being hypoglycemia as IGF-I also activates the insulin receptor).

Thats a long winded way of asking why we want GH levels to go up but IGF-I levels to go down (given the correlation with many cancers and other conditions)?

Thanks,

Allan.

Do we want GH (growth hormone) levels to go up? Not been much discussion about it here. Searching I found this:

GH is released during fasting and peaks overnight usually. Children grow in their sleep because of this! GH does not usually cause growth in adults where its main role is to prevent protein from being used to provide energy and so protect your muscles.

Turning to IGF-I, although Dr M did find his total IGF-I (or IGF-1 or IGF1) levels reduced after following 5:2 this has not been confirmed in a scientific trial, and some other individuals have had ambivalent results. The way you fast and what you eat may be critical... or not.

It's also unclear how much total IGF-I (as measured in Dr M's case) really matters when it is free IGF-I i.e. the IGF-I that is not bound to one of the IGF-BPs (IGF binding proteins) that is potentially dangerous, and this may be less than 1% of total IGF-I.

In short, it's complicated, as you probably already know - see for instance an abstract here and our own home-grown topic here.

Would be great to hear Dr Longo's views about this...

Would be great to hear Dr Longo's views about this...

Here he is talking about fasting in mice and cancer / chemotherapy....



2m35 "Fasting is most extreme environment.. cancer cells can't deal with it ... reduction in glucose, reduction in growth factors."

Contains video of lab animals.

I would not trust the scales with the "body fat" measurements. They are taking very basic measurements and trying to produce a very complicated measurement of your body composition.

These scales are used in some hospitals, but they are very prone to reading oddly depending on several factors. Specifically, you are supposed to get a more accurate reading if you take a reading after going to the toilet (eliminate as much as possible solid and fluid waste) and avoid taking a measurement within 20 minutes of either eating or drinking, according to the manufacturers. It probably improves further the longer you can leave it. I would also expect that dry skin on the hands and feet, where the contact is made, would also drastically affect the measurements.

The scales are mostly an algorithm device, so they take your word for your height, gender, activity level (where it asks for it) etc, and then makes assumptions based on your weight and the resistance/conductance between your hands or feet, or on really posh versions, both.

If you really want to try to see how accurate your body fat scales are, try telling them that you are of the opposite gender - keep your other readings the same. Or tell it you are a few centimetres taller/shorter. The difference may be startling!

It is assumed that men have denser bones than women, which will probably have been factored into the algorithms, and the height/weight measurements are being used to calculate BMI. The resistance/conductance parts put me in mind of those Victorian quack-medicine devices, from when electricity was borderline magic.

The best possible ways of measuring your body composition are both difficult and expensive to access - either a total body device as the Hairy Bikers were put into at the beginning of their diet programme (looks like a bubble car!) or a DEXA/DXA scan, or an MRI scan.

Thanks Esmecat,

My local gym has a bod pod which uses a technique called "Air Displacement Plethysmography" to calculate body composition so I think I will arrange to have that done and on the same day I see what my scales say and see how the calculations compare.