The FastDay Forum

Hi everyone, I started the 5:2 diet last Thursday and before I started I had all my blood tests done. I am just trying to get some info about IGF-1. I have read Michael's book and looked at his blood test results but they seem to be in a different to my results, maybe they are different in Australia? My IGF-1 says 41 nmol/L is this high/low? On the results I got it suggests that the range is 12-42......
Thanks

Hi Noexcuses - I just checked my copy of the book, the units are the same but the range MM quotes is 11.3 - 30.9 nmol/l

The problem is that almost none of us in the UK have had the IGF-1 test done because the NHS will not offer it and it is expensive otherwise, but I expect Carorees will be along shortly to help and advise... Sorry this is not much use!

Welcome to the forum Noexcuses and well done for getting all your tests done before you started. I wish I had done the same! I started a topic about this a while ago (to encourage people to take all possible measurements before they start) but I don't think it has changed the world yet.

Your measurement (like Dr Mosley's) is for total IGF-I (aka IGF1, IGF-1). Most IGF-I in the blood is actually inactive because it is bound to 'binding proteins' in particular IGF-BP3, and it is only the active IGF-I which can pass on the 'grow grow grow' signals to cells and hence be potentially carcinogenic. Active IGF-I is often less than 1% of total IGF-I. So how important is total IGF-I as a figure? I don't think anyone really knows.

Although Dr Mosley did lower his total IGF-I significantly during his initial period of 5:2, we've not seen any confirmation of these results in a trial or indeed anecdotally. It is possible that IGF-I may be reduced more by reduced protein intake than by the limited fasting intervention of 5:2, although as you know from the book/programme much longer fasting does reduce total IGF-I dramatically (but then it also involves zero protein intake!)

I hope you get on well with 5:2 and if so please let us know here in due course how your bloods have changed after following it! If you felt able, it might be good to keep a food diary or at least have some sort of record of what you have been eating as well as how much - I don't think Dr Mosley did this so it makes it harder to speculate on why his IGF-I went down...

Hi everyone, I started the 5:2 diet last Thursday and before I started I had all my blood tests done. I am just trying to get some info about IGF-1. I have read Michael's book and looked at his blood test results but they seem to be in a different to my results, maybe they are different in Australia? My IGF-1 says 41 nmol/L is this high/low? On the results I got it suggests that the range is 12-42......
Thanks

41 nmol/l is 41/0.131 = 313 ng/ml (or microgram per litre) which is fairly high, double the measured levels in Harvie's 2-day diet trial.

Suggested ranges :-

Adults Male range, Mean, Female range, Mean
21 – 30 Years: 155 – 432 289 87 – 368 237
31 – 40 Years: 132 – 333 226 106 – 368 225
41 – 50 Years: 121 – 237 160 118 – 298 205
51 – 60 Years: 68 – 245 153 53 – 287 172
61 – 70 Years: 60 – 220 132 75 – 263 180
71 – 80 Years: 36 – 215 131 54 – 205 156

viewtopic.php?f=10&t=3007

Thanks everyone appreciate the input