Medical experts, including Dr. Shraddhey Katiyar, emphasize that muscle loss, rather than fat gain, is a key indicator of accelerated aging and declining health. Skeletal muscle is crucial for regulating metabolism, protecting organs, and buffering against chronic diseases. Inactivity and poor nutrition drive muscle deterioration, which can be mitigated by regular exercise and sufficient protein intake. Weak leg muscles are identified as a stronger predictor of early mortality than traditional markers like cholesterol.