The potential of near infra-red interactance for predicting body composition in children

Objective: To establish whether near infra-red interactance (NIRI) has pote ntial for use instead of skinfold thickness (SFT) measurements in the asses sment of body composition in young children. Design: Strengths of relationships were established between NIRI or SFT mea surements and four-component model (4-CM) assessments of body composition. Subjects: Nineteen boys and 19 girls, aged 8 - 12y. Measurements: 4-CM estimates of body composition were obtained from measure ments of body weight, body volume, bone mineral content and total body wate r. SFT and NIRI were measured at the same four recognized sites (biceps, tr iceps, subscapular and suprailiac). Results: All children subjectively expressed a preference for NIRI rather t han SFT calipers. Although SFTs were slightly more strongly and consistentl y related to 4-CM estimates, NIRI measurements at the biceps, subscapular a nd sum of four sites were significantly related to body composition indices . Subscapular NIRI measurements were as successful as subscapular SFTs in r anking subjects relative to 4-CM fatness, both techniques being most succes sful at lower levels of fatness. Conclusion: NIRI has potential for use instead of SIFT for estimating body composition in young children. its contribution may prove to be greatest in sick children in whom SIFT measurements may be unwelcome, and weight-for-h eight indices of little value due to abnormalities of water distribution. H owever, greater numbers are required to develop child-specific prediction e quations and the viability and validity of NIRI in pediatric patients is st ill to be evaluated. Descriptors: four-component model; body fat; fat-free mass; skinfold thickn ess.