Psychosocial mediators of dietary change among Hispanic/Latina breast cancer survivors in a culturally-tailored dietary intervention.

OBJECTIVE
To examine psychosocial mediators of the effect of a culturally-tailored dietary intervention on dietary change among Hispanic/Latina breast cancer survivors.

METHODS
Hispanic/Latina breast cancer survivors (n=70) were randomized to receive either a 12-week theory- and culturally-tailored dietary change program (intervention group, n=34), or standard-of-care printed recommendations (control group, n=36) (ClinicalTrials.gov NCT01414062). Fruit/vegetable intake (F/V), % calories from fat, and hypothesized psychosocial mediators were assessed at baseline, 6 and 12-months. ANCOVA assessed intervention effects on psychosocial mediators at 6 and 12 months. Mediation analysis bootstrap methods evaluated the indirect intervention effects on dietary intake at 6 and 12 months through changes in psychosocial mediators at 6 and 12 months.

RESULTS
Compared to controls, at 6 and 12 months the intervention group reported greater improvements in stages of change (P<0.001, P<0.001, respectively), self-efficacy (P=0.009, P=0.002, respectively), and taste/snack-preference for F/V (P=0.045, P=0.002, respectively); at 12 months the intervention group reported a decrease in chance-oriented external locus of control (P=0.02). At 6 months, mediation analysis showed that the intervention effect was associated with an increase of 1.0 (95% CI: -0.1 – 2.4) serving/day of F/V, compared to the control group, although no indirect effect through the hypothesized psychosocial mediators was observed. At 12 months, the intervention was associated with an increase in 0.5 serving/day F/V through improved taste/snack-preference for F/V at 6 and 12 months (95% CIs: 0.1 – 1.3, 0.0 – 1.4, respectively).

CONCLUSIONS
Future programs can target improving taste/snack-preference for F/V to promote dietary change in Hispanic/Latina breast cancer survivors.