BACKGROUND

This study evaluates the effectiveness of adding a diet smartphone application to standard counseling to modify dietary composition over the long term (12 months).

METHODS

A randomized, controlled, multicenter clinical trial was conducted involving the participation of 833 subjects from primary care clinics (415 to the intervention (counseling + application) group (IG) and 418 to the control (counseling) group (CG)). Both groups were counseled about a healthy diet and physical activity. For the 3-month intervention period, the IG was also trained to use a diet smartphone application that involved dietary self-monitoring and tailored feedback. Nutritional composition was estimated using a self-reported food frequency questionnaire.

RESULTS

An analysis of repeated measures revealed an interaction between the group and the percentages of carbohydrates ( = 0.031), fats ( = 0.015) and saturated fats ( = 0.035) consumed. Both groups decreased their energy intake (Kcal) at 12 months (IG: -114 (95% CI: -191 to -36); CG: -108 (95% CI: -184 to -31)). The IG reported a higher percentage intake of carbohydrates (1.1%; 95% CI: 0.1 to 2.0), and lower percentage intakes of fats (-1.0%; 95% CI: -1.9 to -0.1) and saturated fats (-0.4%; 95%CI: -0.8 to -0.1) when compared to the CG.

CONCLUSIONS

Better results were achieved in terms of modifying usual diet composition from counseling and the diet smartphone application compared to counseling alone. This was evaluated by a self-reported questionnaire, which indicated an increased percentage intake of carbohydrates, and decreased percentage intakes of fats and saturated fats.