Use skinfold calipers
Use bioelectrical impedance scales
Use DEXA scan
Use hydrostatic weighing
Use air displacement plethysmography
Use body circumference measurements
Use BMI as an indirect estimate
Use waist-to-hip ratio
Use waist-to-height ratio
Use ultrasound body fat measurement
Use MRI or CT scan
Track changes over time with the same method
Measure under consistent conditions
Compare results with age- and sex-specific norms