Samsung Health Body Composition Alternative

Samsung Galaxy Watch uses Bioelectrical Impedance Analysis (BIA) to measure body composition directly from your wrist. The watch sends a weak electrical signal through two electrodes on the back of the watch case and two on the side buttons — you complete the circuit by touching the side buttons with your fingers during a 15-second measurement. The BIA sensor measures resistance to the electrical signal, which varies based on tissue composition (fat, muscle, water). It reports body fat percentage, skeletal muscle mass, BMI, body water percentage, and basal metabolic rate. Clinical validation studies show ±3–5% deviation from DEXA scans, with accuracy varying based on hydration level, time of day, and recent exercise.