Objective: The purpose was to examine whether a 1-h intervention would help increase fruit consumption in motivated individuals and to study the role of self-regulatory mechanisms in the behaviour change process, with a particular focus on dietary planning and action control.
Methods: A randomised controlled trial compared a 1-h online intervention with controls in 791 participants. Dependent variables were fruit intake, planning to consume and dietary action control.
Results: Experimental condition by time interactions documented superior treatment effects for the self-regulation group, although all participants benefited from the study. To identify the contribution of the intervention ingredients, multiple mediation analyses were conducted that yielded mediator effects for dietary action control and planning.
Conclusions: A very brief self-regulatory nutrition intervention was superior to a control condition. Dietary planning and action control seem to play a major role in the mechanisms that facilitate fruit intake.