Development and validation of the New Somatomorphic Matrix-Male : a figural rating scale for measuring male actual-ideal body discrepancy

This study aimed to develop and examine the validity evidence of the New Somatomorphic Matrix-Male (NSM-M) as a measure of actual-ideal body discrepancy. The NSM-M is a visual matrix of 34 male bodies that vary along two dimensions: body fat percentage (range = 4-40%) and muscularity (fat-free mass index; range = 16.5-30 kg/m 2; 36.4-66.1 lbs/m 2). In Study 1, participants were 2,733 sexual minority males recruited via a geosocial networking smartphone application. Participants selected their "actual" and "ideal" bodies on the NSM-M and additionally completed questionnaires measuring body dissatisfaction, eating disorder symptoms, quality of life, and anabolic steroid use. In Study 2, participants were 33 males from a community sample. They completed the NSM-M across two sessions, 7-14 days apart. NSM-M scores demonstrated concurrent and convergent validity as a measure of male body dissatisfaction. In addition, NSM-M scores discriminated between steroid users and nonusers, and between body mass index categories. The NSM-M also demonstrated sound test-retest reliability across a 7- to 14-day period. In sum, the NSM-M is validated figural measure of male actual-ideal body discrepancy with notable strengths, including fast administration time and enhanced ecological validity.