>>76394849
>your muscle mass is actually the average for guys in their 50s
For skeletal muscle mass, I trust neither the numbers on these scales nor that study.

I was going by FFMI. The average for healthy young males in Switzerland 20 years ago was 18.9 according to this study:
https://pubmed.ncbi.nlm.nih.gov/12080449/

Mine is 20.8, yours is 16.9.