Let them eat fruit! The effect of fruit and vegetable consumption on psychological well-being in young adults: A randomized controlled trial
This 2017 study recruited 171 low fruit and vegetable (FV)-consuming young adults (aged 18-25), and randomly assigned them into one of three conditions: an ecological momentary intervention (EMI) involving text message reminders to increase FV intake as well as vouchers to buy FV; fruit and vegetable intervention (FVI) providing the subjects with two additional servings of FV on top of their regular diet; and the control condition which was the participants’ normal day-to-day diet. The purpose was to research the effects of these 14-day interventions promoting greater FV consumption. Depressive and anxiety symptoms were measured pre- and post-intervention while positive mood, vitality, flourishing and flourishing behaviors (curiosity, creativity, and motivation) were documented on a nightly basis using a smartphone survey. Blood samples were taken before and after the interventions took place to examine vitamin C and carotenoid levels. In addition, psychological expectancies about the benefits of FV were taken to test as mediators of psychological change. The results showed improvements in psychological well-being (increases in flourishing, vitality and motivation) in only the group that received 2 supplementary portions of fruits and vegetables (the FVI intervention group), across the 14 days relative to the other condition groups. Intervention benefits were not mediated by vitamin C, carotenoids, or psychological expectancies but this study demonstrated young adults react more positively to provision of high-quality, fresh fruits and vegetables, rather than reminders and vouchers to encourage increased FV intake. Significant short-term improvements in their psychological well-being were seen, which provides early proof-of-concept that giving young adults fruits and vegetables to eat can have psychological benefits even over a short period of time.