#622: Body Composition Testing: Methods & Interpretation – Prof. Grant Tinsley

Body composition testing is widely used in research, sport and clinical practice. But what are these methods actually measuring, and how much confidence should we place in the numbers they produce? In this episode, we examine the assumptions behind common approaches including DXA, bioelectrical impedance, and skinfold measurements. We discuss the distinction between accuracy and reliability, the value and limitations of repeated measurements, and how coaches, clinicians, researchers and individuals can select an appropriate method and interpret the data without overstating its precision. Joining Danny to discuss these issues is Professor Grant Tinsley, Professor of Human Performance at Texas Tech University and Director of its Energy Balance and Body Composition Laboratory. Timestamps: [03:04] Grant Tinsley's research [05:25] What body composition means [08:50] Skeletal muscle mass vs. fat-free mass vs. lean soft tissue [11:51] How different methods estimate body composition [23:38] Group vs individual accuracy [31:09] Standardizing testing conditions and assessments [36:36] Reliability testing thresholds [40:08] Understanding phase angle in bioelectrical impedence results [45:02] Consumer devices [50:55] Not all benefit from monitoring [54:14] Using data wisely [01:02:55] Key Ideas (premium-only) Links/Resources: Go to episode page (references, bio, study notes) Join the Sigma newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course