This randomised controlled trial verified the efficacy of an implementation intentions intervention ( n = 24) to promote fruit and vegetable consumption among childbearing age women at risk for gestational diabetes mellitus against a control condition based on the question-behaviour effect ( n = 26). There was only a significant time effect ( F(2,85) = 5.69, p = 0.0048). Both groups increased their vegetable consumption compared to baseline at 3 months ( p = 0.0022) and 6 months ( p = 0.0042). There were no significant effects on weight, waist circumference and blood glucose levels. Implementation intentions and the question-behaviour effect appear to be effective behaviour change techniques to promote vegetable intake among this high-risk population.
Keywords: childbearing age women; fruit and vegetable; gestational diabetes mellitus; implementation intentions; question–behaviour effect.