Finally we have an answer

I went to the Institut für Stoffwechselforschung ( Institute of Metabolism Research) in  Frankfurt and met with Dr Thomas Konrad.  Since 2001, the ISF is the only German study center to participate in the EU-funded RISC study ( www.egir.org ) "Relationship between Insulin Sensitivity and Cardiovascular Risk" (QLRT-CT-2001-01252). The study includes healthy 1500 people aged between 30 and 60 throughout Europe. It looks at the effects of lifestyle, environmental factors as well as gender-specific features on the insulin action and atherosclerosis in the long-term course are examined. Currently the 3rd follow-up is in progress since 2001 . In the meantime, more than 60 publications have been published that cover the aspects of "genomics", "proteomics" and "metabolomics".

So I think it is fair to say these people know what they are talking about.  I explained that I am running 50-100km  a week,  eat a healthy diet but my weight is always going up.  I have added weight training and more core work to the running to help improve things,  all to no avail.

Dr Konrad reviewed all the test result of various bloods, blood pressure and heart and thyroid exams.  He was of the opinion  that somewhere my body is under stress causing it to use the insulin  to store food as fat.  He noted my family history where my father died of a stopped heart at 79 and my mother diabetes  The issue was,  given my healthy heart and good blood results there was nothing to indicate where.  

Thus I went through several hours of tests.  The first was to monitor my blood pressure  over a period where I first lay down and rested,  then stood,  then sat and stood and finally sat  and breathed deeply.  Then a lung function test.  Finally a test on  a stationary bike with a ECG and respiration  mask  to monitor how my body reacts under physical stress.  

The first two where as expected showing a healthy heart,  with the only thing of note being the change when I went from  sitting to standing not being as good as expected. 

The bike test was interesting, I cycled against increasing resistance and got up to 150 watts which I was told was good, especially as I didn't break into a sweat.  

They measure my VO2 max whic was 48, again rather good.  Then they found the issue.  The measure of Pulse Wave Velocity   which indicates arterial stiffness was rather bad.  This was the cause of the stress and thus the weight gain. I am trying to do too much

Dr Konrad wanted me  to do the following things 

1) Eat breakfast like a king, lunch like a farmer and dinner like pauper.
2) Eat low slow carbs and protein. 
3) Change training to reduce/remove long endurance runs and strength training
4) Focus on interval training

I have another appointment in two weeks to review the effects of the change.

I have asked several questions 

1) How long should each interval session be? 30mins?  60mins?
2) How long should each intervals be? 
3) How long should the recovery be 1min 2 min? More?
4) How frequent should the session be?
5) Is a swim recovery session of < 30mins once a week ok to do?
6) I take it no weights or core work like sit ups should be done?