Social Desirability Trait Is Associated with Self-Reported Vegetable Intake among Women Enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children.

Background: The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) Fresh Start (WFS) is a randomized controlled trial of nutrition education to promote farmers' market fruit and vegetable (F/V) purchases and consumption among women enrolled in WIC.

Objectives: Using baseline data from WFS to examine associations between social desirability trait, the tendency to respond in a manner consistent with expected norms, and self-reported F/V intake and to determine whether associations, if found, are moderated by participant characteristics.

Design: Cross-sectional.

Participants/setting: Seven hundred forty-four women enrolled in WFS. The setting is a New Jersey-based WIC agency located in a densely populated urban area.

Measures: Items assessing participant characteristics, a short form of the Marlowe-Crowne Social Desirability Scale, and validated measures of the frequency and quantity of F/V intake.

Statistical Analyses: Linear regression analysis to examine associations between social desirability trait and F/V intake and hierarchical regression analysis to test for moderation by participant characteristics of the associations between social desirability trait and F/V intake.

Results: Social desirability trait was significantly associated with times per day vegetables were reported to have been consumed (β=0.08, P=0.03). The association was moderated by breastfeeding status. Among breastfeeding women, social desirability trait was unrelated to reported intake, whereas among non-breastfeeding women, it was positively associated with intake (a 1-unit increase in the social desirability score was associated with a 0.12 increase in times per day vegetables were reported to have been consumed).

Conclusions: Social desirability trait is associated with self-reported vegetable intake among WIC participants generally and non-breastfeeding participants in particular and should be assessed in these groups. Replication studies with comparative measures of "true intake" are needed to determine whether social desirability trait biases self-reports of vegetable intake or whether those with a high social desirability trait consume vegetables more often.