Abstract
BACKGROUND: Forming specific health plans can help translate good intentions into action. Mobile text reminders can further enhance the effects of planning on behavior. OBJECTIVE: Our aim was to explore the combined impact of a Web-based, fully automated planning tool and mobile text reminders on intention to change saturated fat intake, self-reported saturated fat intake, and portion size changes over 4 weeks. METHODS: Of 1013 men and women recruited online, 858 were randomly allocated to 1 of 3 conditions: a planning tool (PT), combined planning tool and text reminders (PTT), and a control group. All outcome measures were assessed by online self-reports. Analysis of covariance was used to analyze the data. RESULTS: Participants allocated to the PT (mean(saturatedfat) 3.6, mean(copingplanning) 3) and PTT (mean(saturatedfat) 3.5, mean(copingplanning) 3.1) reported a lower consumption of high-fat foods (F(2,571) = 4.74, P = .009) and higher levels of coping planning (F(2,571) = 7.22, P < .001) than the control group (mean(saturatedfat) 3.9, mean(copingplanning) 2.8). Participants in the PTT condition also reported smaller portion sizes of high-fat foods (mean 2.8; F(2,569) = 4.12, P = .0) than the control group (mean(portions) 3.1). The reduction in portion size was driven primarily by the male participants in the PTT (P = .003). We found no significant group differences in terms of percentage saturated fat intake, intentions, action planning, self-efficacy, or feedback on the intervention. CONCLUSIONS: These findings support the use of Web-based tools and mobile technologies to change dietary behavior. The combination of a fully automated Web-based planning tool with mobile text reminders led to lower self-reported consumption of high-fat foods and greater reductions in portion sizes than in a control condition. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number (ISRCTN): 61819220; http://www.controlled-trials.com/ISRCTN61819220 (Archived by WebCite at http://www.webcitation.org/63YiSy6R8).