Body composition analysis techniques in the aged adult: indications and limitations

Body composition analysis allows division of the body into different compartments on the basis of differing physical properties. A variety of techniques are available for measuring body composition. This review describes the changes that occur with increasing age, their significance and also the limitations of available body composition analysis techniques when applied to the elderly.

Studies have shown the development of changes in body composition with ageing that have important consequences for health. Alterations in body fat content and particularly body fat distribution are associated with adverse metabolic effects and increased cardiovascular risk. Reduced skeletal muscle mass and strength (sarcopenia) are common in the elderly with important effects on function and outcome. A range of techniques are available for measuring body composition. However, changes in body composition with ageing, particularly altered composition of the constituents of fat-free mass, and changes in fat distribution, may lead to measurement errors with standard body composition assessment methodology.

Measurement of body composition provides information of importance to health and function. Techniques used for assessment should be those unaffected by age-related changes in body composition, or those that have been adapted or validated in this age group. Particular roles of these techniques in the elderly include screening or surveillance of those at risk of malnutrition, and monitoring a range of chronic illnesses that are prevalent in older individuals.