How does dehydration (e.g., after heavy exercise) typically affect a single-frequency BIA measurement of body fat percentage if the device and algorithm do not account for hydration status?

• A. Dehydration reduces electrical conductivity (increases impedance), causing the device to overestimate body fat percentage
• B. Dehydration has no impact on BIA estimates because impedance is independent of total body water
• C. Dehydration causes BIA to estimate bone mineral density directly rather than fat percentage, making the body fat output irrelevant
• D. Dehydration increases conductivity and therefore causes the device to underestimate body fat percentage markedly

Answer: (A)