How valid are our reference standards of nutrition?

The validity of anthropometric measurements in the assessment of nutritional status depends on the use of appropriate standards. The most commonly used standards for triceps skinfold thickness and mid-arm muscle circumferences are based on Jelliffe's and Frisancho's tables. In this study we compared these two standards in a population of healthy subjects and patients with a variety of pathological disorders. The study showed that the correlation between these two standards was poor. When Frisancho's standards were used as "gold standards," the positive predictive value of Jelliffe's standards for triceps skinfold thickness was only 22% and for mid-arm muscle circumference only 53%; the false positive results for triceps skinfold thickness and mid-arm muscle circumference were 28% and 27%, respectively. This study emphasizes the need to develop appropriate standards for the studied population. Until such standards are available, workers assessing nutritional status in population studies would be advised to interpret their findings with caution, and, on the basis of this study, we recommend the use of Frisancho's standard in preference to Jelliffe's standards.