Yes, sorry, thank you. The important quantity would be metabolic rate divided by the best prediction from the known relevant variables, as you say. It was once a test for hypothyroidism, so whatever the last word pre-blood test was should be good enough.

As I say, Broda Barnes found this test wanting and preferred waking axillary temperature (for females, on the correct days; for males, anytime), but it should be plenty good enough to establish that there's something funny going on. The problem is to draw the attention of medical science to it at all. I trust them to sort out the details.