As medicine has transformed HIV from a fatal diagnosis into a manageable chronic condition, a quieter reckoning has emerged: longevity does not guarantee metabolic safety. Researchers at UC San Francisco have found that people whose HIV is fully suppressed by modern treatment still carry hidden scarring in their fat tissue — scarring that predisposes them to type 2 diabetes regardless of their body weight or the medications they take. The discovery reminds us that what is invisible to the eye, and even to the scale, may still be written in the body's deeper language.