Social desirability trait is associated with self-reported vegetable intake among women enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children

Authors: DI NOIA, JENNIFER - William Patterson University; CULLEN, KAREN - Children'S Nutrition Research Center (CNRC); MONICA, DOROTHY - St Joseph'S Health Center

Submitted to: Journal of the Academy of Nutrition and Dietetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2016
Publication Date: 9/7/2016
Citation: Di Noia, J., Cullen, K.W., Monica, D. 2016. Social desirability trait is associated with self-reported vegetable intake among women enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children. Journal of the Academy of Nutrition and Dietetics. doi:10.1016/j.jand.2016.07.008.

Interpretive Summary: 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 the Special Supplemental Nutrition Program for Women, Infants and Children (WIC). This study examined whether the social desirability (SD) trait influenced the mothers' tendency to answer survey questions because they wanted to please the study investigators and if this trait influenced how they reported their diet. Seven hundred forty-four women enrolled in WFS in New Jersey. The mothers completed a short form of the Marlowe-Crowne Social Desirability Scale and also reported how much F/V they ate. We found that the SD trait was significantly associated with times per day vegetables were reported to have been consumed; the mothers with high SD reported eating more vegetables. This trait may influence study results and should be measured.

Technical Abstract: 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. Our objectives were to use 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. A cross-sectional design was used. Seven hundred forty-four women enrolled in WFS participated. The setting was a New Jersey-based WIC agency located in a densely populated urban area. Our measures were 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. 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 were used. Social desirability trait was significantly associated with times per day vegetables were reported to have been consumed (B=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). We concluded that 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.