The development and effectiveness of an ecological momentary intervention to increase daily fruit and vegetable consumption in low-consuming young adults

Abstract

Objectives To develop and test the effectiveness of a mobile-phone based ecological momentary intervention (EMI) to increase fruit and vegetable (FV) consumption in low-consuming young adults. Methods A two-week randomised controlled trial of low-FV consuming young adults ages 18–25 years (n = 171) compared three conditions: ecological momentary intervention (EMI), fruit and vegetable intervention (FVI), and a diet-as-usual control (ANZCTRN12615000183583). Participants in the EMI condition were sent two targeted text messages a day for 13 days and were asked to increase daily FV consumption to at least five servings. These messages were designed, using the Health Action Process Approach, to address salient beliefs identified as effective in a preliminary focus group investigation. Participants in the FVI condition were provided two servings of FV a day (carrots, kiwifruit or oranges, and apples) to eat in addition to their current diet. Control participants ate their normal diet. Participants reported their daily servings of FV each evening during the study using a smartphone-delivered survey. Blood samples testing plasma vitamin C and total carotenoids were taken pre- and post-intervention as an objective biomarker of FV intake. Results Participants in the EMI and FVI conditions reported higher daily servings of FV – approximately +1 serving per day more compared to control (EMI = 3.7 servings/day; FVI = 3.7 servings/day; Control = 2.8 servings/day) and approximately +1.2 servings compared to baseline. Increases in objective biomarkers for the experimental conditions supported the validity of self-reported FV consumption. Conclusions Our results provide initial proof of concept that EMI strategies (with minor financial assistance) are as effective as giving FV in increasing FV consumption in educated, low-consuming young adults.