Bioelectrical Impedance Analysis (BIA) and Multi-Frequency Tech
BIA is the technology found in most consumer "smart scales." It works by sending a tiny, painless electrical current through the body.
Because fat contains very little water, it resists the current (impedance), while muscle, which is roughly 70–75% water, allows the current to pass easily. In 2026, advanced Multi-Frequency BIA (MF-BIA) devices, such as the InBody 770, use different frequencies to measure both intracellular and extracellular water, significantly improving accuracy.
While convenient, BIA is sensitive to hydration levels. In 2026, users are advised to measure at the same time each day—ideally in a fasted state—to minimize fluctuations. Despite these variables, top-tier 2026 home scales now show a 98% correlation with DXA scans when used under consistent conditions, making them excellent tools for tracking trends over time rather than providing a single "perfect" snapshot.