Ray Marx1, John P. Porcari1, Scott Doberstein1, Richard Mikat1, Abigail Ryskey1, Carl Foster1. Ability of the LeanScreen App to Accurately Assess Body Composition. 1Department of Exercise and Sport Science, University of Wisconsin-La Crosse, La Crosse, WI, USA.


Introduction: Waist-to-hip ratio (WHR) and percent body fat (%BF) are commonly used to assess body composition in health and wellness settings. While there is only one commonly used method for measuring WHR, %BF can be determined many ways. However, the accuracy, cost, and ease of use of these methods vary greatly. The LeanScreen app is a new method designed to determine WHR and %BF using photographs. Purpose: This study was designed to assess the accuracy of the LeanScreen app to determine WHR and %BF against laboratory-validated methods. Eighty subjects (40 males; 40 females) participated in this study. Waist-to-hip ratio was manually measured and %BF was determined using the BOD POD. Photographs of each subject were taken from the front and side with the LeanScreen app according to the procedures demonstrated by the program software. Results: There was no significant difference in WHR between the LeanScreen app (.81 ± .078) and manual (.81 ± .087) WHR measurement (r=.83). Additionally, it was found that 73 subjects (91%) were within the 95% confidence intervals of the mean. Overall, %BF was significantly underpredicted by the LeanScreen app compared to the BOD POD (20.2 ± 7.74 vs. 21.6 ± 8.77). Although there was a high correlation between the two methods (r=.82), only 35 subjects (44%) were within ± 3% of BOD POD derived %BF and there was a high degree of variability between methods (SEE=5.1). Conclusion: Based upon the results of this study, the LeanScreen app accurately determines WHR, but does not accurately determine %BF on an individual basis.