Social desirability bias in self-reported dietary, physical activity and weight concerns measures in 8- to 10-year-old African-American girls: results from the Girls health Enrichment Multisite Studies (GEMS)

Background. Social desirability (SocD) may bias children's self-reported health behaviors and attitudes and confound relationships with health outcome measures. Methods. Ninety-five, 8- to 10-year-old African-American girls completed dietary recalls, a physical activity checklist, psychosocial questionnaires related to diet, and physical activity; and 3 days of physical activity monitoring. Potential SocD construct bias was investigated by comparing designated criterion measures of physical activity, beverage intake, and body mass index (BMI) with respective self-reported measures related to activity, beverage preferences, and body image and weight concerns in cross-sectional regression models. Potential confounding by SocD of associations between self-reported behaviors with BMI was assessed using change-in-coefficient regression analyses. Results. Controlling for age and BMI, overestimates of self-reported activity (P = 0.02), underestimates of sweetened beverage preferences (P= 0.02), and lower ratings of weight concems and dieting behaviors (P's < 0.05) were related to SocD. Confounding by SocD of associations between self-reported physical activity and energy intake with BMI was found. Conclusions. In 8- to 10-year-old African-American girls, SocD was found to bias self-reports of diet and physical activity and confound associations between BMI and self-reported physical activity and energy intake. Methods to measure and control SocD bias are needed to reduce potential distortion of relationships between diet and physical activity and health outcomes. (C) 2004 The Institute For Cancer Prevention and Elsevier Inc. All rights reserved.