GLOSSARY

Thigh Circumference is circumference around the thigh at a defined site. The exact landmark and posture are essential for comparing repeated values.

Circumference measurements require a defined anatomical landmark, tape tension, posture and breathing phase when relevant. A change can reflect muscle, fat, fluid or measurement technique. Waist and hip ratios are only comparable when the same protocol and denominator are used. Record the raw measurements as well as calculated indices. These low-cost measurements can help follow trends, but they do not directly separate all tissues or provide a substitute for an assessment when health concerns are present.

Skinfold calipers measure a compressed double layer of skin and subcutaneous tissue at standardized sites. Site location, examiner skill and technique influence results. A sum of skinfolds can track changes without converting it to body-fat percentage. Predictive equations add assumptions about fat distribution and the population used to develop them. Repeated values are most useful when the same trained assessor follows the same protocol, and they should not be treated as a direct measurement of visceral fat.

Body-composition models divide the body into components according to a defined level. A two-component model often separates fat mass from fat-free mass. Adding measured water or mineral information can reduce some assumptions in more complex models, but no model removes all error. Molecular, cellular and tissue descriptions are different ways of organizing the same body. Before comparing results, identify the model, measured variables and assumptions rather than treating all reported components as directly measured anatomical tissues.