Muscle health is linked to how well we fight off disease and our longevity. But healthy muscles aren’t just about the size of a bicep or how much we weigh.

An international team of kinesiologists and nutrition experts recently urged doctors to pay more attention to skeletal muscle quality and the ratio of muscle to fat as a key to “metabolic regulation, immune function and overall vitality and functioning.”

“Muscle health estimation could be as important as measuring somebody’s blood pressure,” said longevity expert Dr. Nicolaas Deutz , a professor in the Department of Kinesiology and Sport Management at Texas A&M University and a co-author of the expert review.…