Are intervention effects on fruit and vegetable intake maintained after 48 months of follow-up? A randomised controlled community trial
Maria Cecília Ramos de Carvalho, Mariana Souza Lopes, Patrícia Pinheiro de Freitas, Aline Cristine Souza LopesAbstract
Objective:
To assess whether participants from a transtheoretical model-based intervention maintained increases in fruit and vegetables (FV) intake 48 months after baseline.
Design:
Randomised controlled community trial.
Setting:
A Brazilian primary health care service.
Participants:
Primary health care service users. The control group (CG) received usual care, and the intervention group (IG) received usual care and a 7-month collective intervention to promote FV intake. We analysed individuals with positive changes 12 months after baseline (baseline intake <400 g/d with any increase at 12 months or baseline intake ≥400 g which remained ≥400 g at 12 months, n 2·232). Outcomes were FV intakes at 36 and 48 months after baseline compared to previous intakes to identify maintenance. We used generalised estimating equations models to assess time and intervention effects in follow-up intake.
Results:
Participants were mostly adult women. We identified decreases of 54.4 g/d in fruit intake and 38.5 g/d in vegetable intake at 36 months and increases of 6.9 g/d in fruit intake and 23.4 g/d in vegetable intake at 48 months. According to adjusted models, at 36 months, CG and IG participants presented similar decreases in FV intakes, which means initial changes in the IG were not maintained. At 48 months, small increases in intakes were also similar between IG and CG.
Conclusions:
Intervention participants did not maintain initial changes on FV intake in the long term, and boosters might be necessary to maintain initial increases.