Yes, BMI is a limited, inaccurate proxy measure.

Lean body mass (LBM) – DEXA, InBody, etc. – is a composite of all non-fat body tissue. it is also not a direct measure of muscle tissue. Like BMI, LBM is an inaccurate proxy estimate at best, and grossly outdated.

As of September 13, 2026 –

There is no standardized way to measure total muscle tissue
There is no standardized baseline average to compare #1 to
There is no standardized baseline phenotype to compare #1 and #2 to
There is no standardized way to measure total genetic muscle tissue from birth, or ever
There is no standardized way to measure how much muscle tissue is added via exercise – resistance or extreme cardio (hypertrophy)
There is no standardized way to measure how much muscle tissue is lost via poor diet, exercise, or lifestyle (atrophy)
There is no standardized way to measure how much muscle tissue is lost via aging (sarcopenia)