This supposedly most accurate BMR formula takes into account lean mass and lean mass only.

BMR = 370 + 26.1 * LBM in KG

or if you're too lazy to convert your lbm to kg:

BMR = 370 + 11.9 * LBM in lbs

For example, it suggests that I, having 110 pounds of LBM, have a BMR of 1675 or so.

There are three implications of this formula:

- Your BMR is SOLELY based on your LBM. Why, then, do ectomorphs with less LBM than most people have to eat a lot to gain weight? Why do adolescents have fast metabolisms despite the fact that they don't have as much muscle mass as adults?

- Muscle doesn't boost your metabolism by 20-50 kcal per pound, but rather about 12 kcal per pound. I knew the 50 kcal per pound figure was way off, otherwise bodybuilders would have to eat 8000 calories to maintain their weight!

- Extra fat doesn't affect your metabolism Thus, the obese don't really need 10x their bodyweight. The 10-12x your body weight only applies if you're slightly overweight to fit. Is this really true? I think a pound of fat burns something like 2-3 kcal per day.

Perhaps a more accurate BMR formula would look like this:

BMR = [some constant near 370] + 11.9 * LBM in lbs + [between 2 or 3 * fat in lbs] + [some sort of age factor]

Thoughts?

all these formula's are nice, but if you really wanna see your personal maintanence, you gotta take your body for a test run, go raise your calories for a few weeks untill you stop losing/gaining weight, try a few different macronutrient combo's at the same calories and see how your body reacts!

all these formula's are nice, but if you really wanna see your personal maintanence, you gotta take your body for a test run, go raise your calories for a few weeks untill you stop losing/gaining weight, try a few different macronutrient combo's at the same calories and see how your body reacts!
You're absolutely right, but the purpose of this thread is to explore how body composition and other factors affect your BMR as well.