Interesting…I’ve been on a 5:2 diet since before Christmas, and cut out meat during the week since the new year, rather than ramble on I’ll keep it brief.
– The 5:2 is great (for me), I feel lighter and fresher etc, and I’ve been successfully loosing weight. However one thing to note is that its not recommended for diabetics, however research suggests it does increase your sensitivity to insulin, so I don’t know how it would work for your OH.
– The fast diet is essentially 5:2, however you have 800 calories for the first 2 weeks, then carry on with the 5:2, only having 800 calories. The reason for this is in the first 2 weeks, you’ll get motivated by the rapid loss, and the extra 300 calories over the 5:2 has roughly the same effects, only you won’t be as hangry.
– I’m also doing a bit of 16:8…also works great and you feel great.
– Finally cutting out meat makes a huge difference to my perceived endurance, I feel much more energised on longer rides.
– No notable loss in fitness on rides, and strength seems to have gone up.
N.B. I may be wrong on some of the fast diet info, but this is how I interpret it from YouTube interviews with Dr Michael Mosley.