DXA-derived body composition and mortality risk in older adults

Researchers used DXA, a low-dose X-ray scan that estimates muscle, fat, and bone, to measure body composition in older adults. They then tracked who died during follow-up and compared their scan results. People with less lean tissue, especially muscle, generally had a higher risk of dying. The link between total body fat and death was less clear, so the study does not show that simply having more or less fat determines lifespan.

What this means for you: This supports preserving muscle through regular activity and strength training, but it does not justify buying supplements or chasing a particular body-fat number. The study was observational, so it cannot prove that changing body composition would extend life.