I'm pretty well-versed in nutrition/fitness, and so have tried a diet completely opposite of that which I adhered to back during my fitness modeling days....
Basically, in the last several days, I've increased my calories as much as I can, but have made sure that my protein has been low (~40 grams/day). Consequently, I've dropped down to to 155 pounds, and my waist is 27.5 inches around. I think I'm seeing fat gain also, though, because my face is round (unlike how it was before HRT), and my hips have increased to 37 inches in circumference. That, in combination with the constant muscle pain I feel all over my body and noticing that I can't really flex my chest or arms anymore, have led me to believe that low protein + HRT is enough to do the trick.
This is also pretty significant because I weighed 180 pounds before starting any HRT whatsoever. Hopefully I'll keep seeing muscle loss, though, because as light as I am for 5 ft. 10, my body still wouldn't pass, in my opinion. Oh, and I guess another indication of obvious muscle loss is that (keeping in mind that I'm a university student) my shoulders are ALWAYS sore from carrying around my backpack, which I keep only one textbook in. Pretty crazy.