The study examined whether a dietary planning intervention would help increase fruit consumption among Iranian women focusing on self-regulatory mechanisms in behavior change. We conducted a randomized controlled trial to compare a planning intervention with a control condition in 165 Iranian women (aged 17-48years). Dependent variable was fruit intake, and dietary planning served as the mediator. After baseline assessment (T1) the intervention group received a leaflet on fruit consumption with a planning sheet. Changes were assessed at 3-weeks (T2) and at 3-months follow-ups (T3). Findings showed that the dietary planning intervention led to an increase in fruit intake. Age moderated this mediation. Changes in dietary planning mediated between intervention and fruit consumption in middle aged women. Dietary planning seems to play a role in the mechanism that facilitates fruit intake among Iranian women. This mediation by planning was found in middle aged women (30-48years old), but not in young adult women (17-29years old).