The effect of electronic self-monitoring on weight loss and dietary intake: a randomized behavioral weight loss trial

Abstract

Technology may improve self-monitoring adherence and dietary changes in weight loss treatment. Our study aimed to investigate whether using a personal digital assistant (PDA) with dietary and exercise software, with and without a feedback message, compared to using a paper diary/record (PR), results in greater weight loss and improved self-monitoring adherence. Healthy adults (N = 210) with a mean BMI of 34.01 kg/m(2) were randomized to one of three self-monitoring approaches: PR (n = 72), PDA with self-monitoring software (n = 68), or PDA with self-monitoring software and daily feedback messages (PDA+FB, n = 70). All participants received standard behavioral treatment. Self-monitoring adherence and change in body weight, waist circumference, and diet were assessed at 6 months; retention was 91%. All participants had a significant weight loss (P < 0.01) but weight loss did not differ among groups. A higher proportion of PDA+FB participants (63%) achieved ≥ 5% weight loss in comparison to the PR group (46%) (P < 0.05) and PDA group (49%) (P = 0.09). Median percent self-monitoring adherence over the 6 months was higher in the PDA groups (PDA 80%; PDA+FB 90%) than in the PR group (55%) (P < 0.01). Waist circumference decreased more in the PDA groups than the PR group (P = 0.02). Similarly, the PDA groups reduced energy and saturated fat intake more than the PR group (P < 0.05). Self-monitoring adherence was greater in the PDA groups with the greatest weight change observed in the PDA+FB group.

Figures

Figure 1. CONSORT Diagram

PR, paper record; PDA, personal digital assistant; PDA+FB, personal digital assistant plus feedback.

Figure 2. Proportion of participants adherent to self-monitoring over time (N = 210)

PR, paper record; PDA, personal digital assistant; PDA+FB, personal digital assistant with the added customized feedback program. Based on the nonlinear mixed effects modeling, adherence to self monitoring decreased over time in all treatment groups (P < 0.001). The PDA+FB group was more adherent than the PR group (P = 0.003) and the PDA group was more adherent than the PR group (P < 0.001). There was no significant difference between the PDA and the PDA+FB groups (P = 0.11).