An overview of methods to assess body composition

Abstract

Scientific advancement has led to new technologies in the field of body composition assessment. Surface anthropometry has traditionally been used to assess body composition through the internationally recognised methodology of the International Society for the Advancement of Kinanthropometry (ISAK). However, the commercialisation of devices providing bioelectrical impedance analysis, dual energy X-ray absorptiometry, magnetic resonance imaging, three-dimensional photonic scanning (3DS), air-displacement plethysmography (i.e. Bod Pod), ultrasound techniques and dilution techniques (doubly-labelled water), has led to the adoption of new and often non-standardised, measurement techniques. Practitioners, all over the world, are employing these new technologies to measure and monitor change in body size, shape and composition for the purposes of health management, talent identification and development, optimising physique for sport performance, and enabling sports equipment design and fit. The accuracy and reliability of the technique measures are critical in a field where tracking small changes in an athlete's physique is important. When athletes have their body composition measured across multiple technologies in a non-standardised manner, they often receive varying results which can be confusing and, in some cases, distressing. Currently, no reference or model exists for the standardisation of many of these new devices. There is a lack of awareness of standardisation of technique among both manufacturers & practitioners. There is often a lack of established protocols to ensure best practice in physique assessment. Different protocols can make large differences to the measurement value when they purport to measure the same thing – e.g. waist girth (up to 12% in females); Breathing cycle in 3D scan-derived % fat (15% for end tidal, rising to 28% on inspiration and reducing to 10% in expiration). These two examples underscore the importance of standardising protocols for body composition assessment. This presentation will outline considerations for current best practice to assess body composition. Examples for physique assessment in clinical practice using a selection of the technologies will be provided from the international team of co-authors in the Best Practice Protocols for Physique Assessment in Sport book (to be published by Springer International, November 2017).