The Role of Household Social Support and Undermining in Dietary Change

US adults find it challenging to meet disease prevention dietary recommendations and may participate in interventions to improve dietary quality. Social influences outside of the intervention, including level of social support and undermining of healthy eating in the home, may affect an individual's dietary intake. This secondary analysis examined (1) changes in household social support and undermining of healthy eating across a dietary intervention with household member participation and (2) the relationship between changes in social influences and dietary intake.

Adults (N = 62) with low adherence to cancer prevention dietary recommendations recruited from the Philadelphia area participated in a 20-week dietary intervention focused on psychoeducation about NCI dietary recommendations and skills for behavior change. Half of the participants were also randomized to have an adult household member participate in some intervention contacts with them. Participants completed measures of social support and undermining of healthy eating and dietary intake at baseline and post-treatment (20 weeks).

Fifty-two participants had available data for baseline and post-treatment (i.e., completers). Household social support of healthy eating increased more among participants randomized to have household involvement in the intervention with a medium effect (η² = .11). Fruit and vegetable intake significantly increased among participants with meaningful increases in household social support with a large effect (η² = .37). There were no significant interaction effects of change in household undermining and time on change in dietary intake.

Dietary interventions with a household support component show promise for improving household social support and may impact magnitude of dietary change.