Randomized controlled trial of a telephone-based intervention for child fruit and vegetable intake: long-term follow-up

Background: Telephone-based interventions can be effective in increasing child fruit and vegetable intake in the short term (<6 mo). The long-term efficacy of such interventions, however, is unknown. Objectives: The primary aim of this study was to determine whether the short-term (<6 mo) impact of a telephone-based intervention on children’s fruit and vegetable intake was sustained over a longer term. A secondary aim of the study was to assess the long-term impact of the intervention on the intake of foods high in fat, salt, or sugar (noncore foods). Design: The study used a cluster randomized controlled trial design. Parents were recruited from Australian preschools between February and August 2010 and allocated to receive an intervention consisting of print materials and 4 telephone-counseling calls delivered over 1 mo or to a print information–only control group. The primary endpoint for the trial was the 18-mo postbaseline follow-up. Linear regression models were used to assess between-group differences in child consumption of fruit and vegetables and noncore foods by subscales of the Children’s Dietary Questionnaire. Results: Fruit and vegetable subscale scores were significantly higher, indicating greater child fruit and vegetable intake, among children in the intervention group at the 12-mo (16.77 compared with 14.89; P < 0.01) but not the 18-mo (15.98 compared with 16.82; P = 0.14) follow-up. There were no significant differences between groups at either of the follow-up periods in the noncore food subscale score. Conclusion: Further research to identify effective maintenance strategies is required to maximize the benefits of telephone-based interventions on child diet. This trial was registered at http://www.anzctr.org.au/ as ACTRN12609000820202