I think that one’s REE(resting energy expenditure) is a slightly undervalued method of evaluating muscle gain. It makes sense that as one gains muscle, one’s energy expenditure will increase, and measured changes in metabolism can be a very good indicator of one’s progress.
That said, my own REE has gone up quite a bit since I started weight training. I started out at about 2600 kcal/day and as of this morning measured at 3154 kcal/day. This was done using the REEvue machine that measures VO2max and from what I understand extrapolates upon this and other measurements to determine overall energy expenditure. Very cool device.