This was a DEXA scan, short for dual-energy x-ray absorptiometry. Since the late 1980s, hospitals have used this method to diagnose osteoporosis, and it remains the gold-standard test for bone health. At Canyon Ranch, where I was attending the Longevity8 program, the DEXA scan was presented as a crucial snapshot of what might be diminishing my healthspan. The appeal of the DEXA scan is clear. A DEXA BC (body composition) scan can also distinguish fat from lean muscle, providing a clearer picture of cardiovascular risk, metabolic health, and stroke risk.