The preferred method for measuring body fat percentage is through bioelectrical impedance analysis (BIA) or Dual-Energy X-ray Absorptiometry (DEXA), both of which provide accurate and reliable results. BIA measures body composition by passing a small electrical current through the body, assessing how easily the current flows through fat and lean tissue. DEXA, on the other hand, uses low-level X-rays to differentiate between bone, fat, and lean mass. These methods are considered superior compared to simple caliper measurements, which can be less accurate and more reliant on testing conditions.