For me, it's not roughage. I mix up my veggies all day long - fresh at one meal, steamed at the next. I get a variety of types, as well.
However, all high protein diets I have read any material about do warn against kidney problems and since I've had kidney and urinary tract issues in my adult life, I still suspect this might be what my body is trying to deal with.
They say MRC was developed by doctors, scientists, etc with lots of research - that doesn't eliminate side-effects...and for the record I haven't seen documentation on that or their research. As a librarian...I like to see that too...they haven't provided. I'm still a bit of a skeptic.
When I discussed this with my counselor, she agreed that the higher protein content may be putting stress on my kidneys and suggested I reduce the qty of HNS that I have daily by 1 until I can talk to my doc (I already had an appointment for other reasons, just adding this to the list). She also said a rapid/sudden weight loss can increase the amount of estrogen in my body and give me cramps. So - we shall see!