I would consider getting a physical and labwork done. On your first visit, your physician definitely should rule out diabetes and/or depending on your gender: UTI or a prostate condition.
"Polyuria" is the catch-all term for excessive urination.
I googled around a little, and found some causes - diabetes insipidis being the one that sounds maybe like what you are experiencing.
In this link, patients with diabetes insipidis experience a decrease in Polyuria (excessive urination) when protein in the diet is restricted.
Best wishes tracking this down - it does sound like you're "in the hunt" with finding out what is wrong with you when you notice protein affects your urine output.
1. go for bloodwork
2. urine analysis
3. try eliminating the protein for a day or two and see if the symptoms susbside
I would probably rule out diabetes. Type 2 diabetes is hallmarked by the "3 Ps" polydyspsia (excessive thirst), polyphagia (excessive hunger), and polyuria (excessive urination)...you do not have the first two good luck!!
Thanks for the feedback, I will request a diabetes test just to be safe, and maybe cut out some protein for a period.
I should also note that I currently have quite a high blood pressure for some reason.
To nervous_nikki: I had a urine test to which the doctor deemed fine, but also said that my urine was very clear'(Unconcentrated)'if you like.
Is it possible that i have reduced renal funtion or would that have that showed up as part of my kidney tests?
Some of the test included: Urea - 3mmol/L, creatinine - 69umol/L and protein 77g/L.