“…If so, is rheumatoid sarcopenia a consequence of a more aggressive disease, and therefore, more difficult to treat, or can muscle mass, like adipose tissue, interfere with the therapeutic response? (5,6) The purpose of this letter is not to challenge Baker et al (1), whose article faithfully reflects what we have seen in clinical practice, but only to shed light on the importance for us to improve our ability to phenotype obesity. Metabolically healthy obese, sarcopenic obese, and normal weight obese are phenotypes (7) that rheumatologists need to know to better study and care for their patients.…”