Objective: To assess longitudinal effects of a nutrition intervention on fruit and vegetable (F&V) intake among Primary Health Care (PHC) service participants in Belo Horizonte, Brazil.
Methods: Demographics and health data on 3414 PHC service participants were collected at baseline in 2013-2014. F&V intake was assessed at baseline, 12, 36, and 48 months until 2017-2018. Services were randomized to control (CG, usual care) or intervention (IG, usual care and a Transtheoretical Model-based intervention to increase F&V intake). We performed difference-in-differences (DiD) analysis to identify intervention effects on F&V intake, and sensitivity analyses of participants observed at all timepoints.
Results: Participants were mostly middle-aged, low-income women. Mean baseline intakes were 168.7 g of fruit, 202.0 g of vegetables, and 370.7 g of F&V, with lower fruit in the IG (164.1 g) than the CG (172.3 g). At 12 months, the intervention increased fruit intake in the IG and fruit and F&V intake among individuals with low baseline F&V intake. Fruit intake remained higher at 36 months in the IG. No effect on vegetable intake was identified. According to sensitivity analyses, effects on fruit intake among the complete sample did not remain significant at 36 months, and an effect on fruit intake at 36 months was identified among those with adequate baseline F&V intake. Reductions in F&V intake did not remain significant.
Conclusions: At 12 months, a TTM-based intervention increased fruit intake in the overall sample, and fruit and F&V intake among individuals with low baseline intakes. Repeated interventions may be needed over time.
Trial registration number: RBR-9h7ckx.
Keywords: Food and nutrition education; Fruit; Health promotion; Longitudinal studies; Primary health care; Randomized controlled trial; Vegetables.
Copyright © 2023. Published by Elsevier Inc.