¹Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Medical College of Virginia of Virginia Commonwealth University, Richmond, Virginia, USA

²Department of Psychology, Flinders University, Adelaide, Australia

³Department of Psychiatry, Washington University School of Medicine, St Louis, Missouri, USA

⁴Queensland Institute of Medical Research, Brisbane, Australia

⁵Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA

⁶Virginia Institute for Psychiatric and Behavioral Genetics, Department of Human Genetics, Medical College of Virginia of Virginia Commonwealth University, Richmond, Virginia, USA

Correspondence to: C M Bulik, Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Medical College of Virginia of Virginia Commonwealth University, PO Box 980126, Richmond, VA, 23298-0126, USA. E-mail: cbulik@hsc.vcu.edu

OBJECTIVE: To establish body mass index (BMI) norms for standard figural stimuli using a large Caucasian population-based sample. In addition, we sought to determine the effectiveness of the figural stimuli to identify individuals as obese or thin.

DESIGN: All Caucasian twins born in Virginia between 1915 and 1971 were identified by public birth record. In addition, 3347 individual twins responded to a letter published in the newsletter of the American Association of Retired Persons (AARP). All adult twins (aged 18 and over) from both of these sources and their family members were mailed a 16 page 'Health and Lifestyle' questionnaire.

SUBJECTS: BMI and silhouette data were available on 16 728 females and 11 366 males ranging in age from 18-100.

MEASUREMENTS: Self-report information on height-weight, current body size, desired body size and a discrepancy score using standard figural stimuli.

RESULTS: Gender- and age-specific norms are presented linking BMI to each of the figural stimuli. Additional norms for desired body size and discrepancy scores are also presented. Receiver operating curves (ROC) indicate that the figural stimuli are effective in classifying individuals as obese or thin.

CONCLUSIONS: With the establishment of these norms, the silhouettes used in standard body image assessment can now be linked to BMI. Differences were observed between women and men in terms of desired body size and discrepancy scores, with women preferring smaller sizes. The figural stimuli are a robust technique for classifying individuals as obese or thin.

International Journal of Obesity (2001) 25, 1517-1524

body mass index; silhouettes; norms; figural stimuli