1 0.5 ) 2 m / g k ( x e isnd 0 s a m e e r f t fn a -0.5 i s e c n e r e f f i D -1 -1.5 40-44 vs 45-50 Vs 51-54 Vs 55-59 Vs 60-64 Vs 65-69 Vs 70-74 Vs 75-79 Vs > 80 White men Black men White w omen Black w omen BMC Public Health 2005, 5:41 http://www.biomedcentral.com/1471-2458/5/41 Age-related changes AFiggeu-rreela2ted changes in fat free mass index in older white and black men and women Age-related changes in fat free mass index in older white and black men and women. The Third National Health and Nutrition Examination Survey (NHANES III 1988–94) using Bioelectrical Impedance and DEXA to estimate FFM, and therefore, may not reduce the significance of the pop- ulation-based observation from the current study. Inter-, intra-observer's and instrument bias appear unlikely in the NHANES given the uniform procedural standards for anthropometric measurements. Despite these limitations, the use of anthropometric measurements to estimate FFM and changes in FFM is simple, low cost, and has a predic- tive value of within 3 to 4 percent for 70 percent of the population [33,35] especially when adjusted for age. Finally, the unique strengths of the study include large sample size, standardized procedure for anthropometric measurements and its applicability to the entire United States population. Conclusion In conclusion, we provide additional support for the dif- ferential effect of ethnicity on the loss of FFM and FFMI as the population ages. Regardless of the explanation for these differences, losses in muscle mass have several important health consequences, and perhaps more so for FFM decline. Most notable among these is increased func- tional dependency and mortality. This underscores the public health imperative of an ongoing epidemiological surveillance of the variations in FFM. If properly imple- mented, public health strategies may facilitate the design of targeted optimization of functional independency as the United States population ages. Abbreviations Fat free mass (FFM); Fat free mass index (FFMI); Body mass index (BMI); The Third National Health and Nutri- tion Examination Survey (NHANES III) Competing interests The author(s) declare that they have no competing interests. Authors' contributions TOO conceived the study, participated in the design, per- formed statistical analysis and writing of the manuscript; MHA participated in the design, performed statistical analysis and writing of the manuscript; VB participated in the analysis and writing of the manuscript; RGA participated in conceiving and drafting of the manuscript, AA participated in the drafting of the manuscript, CNR participated in study design, statistical analyses and draft- ing of the manuscript Page 8 of 9 (page number not for citation purposes)