Impact of group nutrition education and surplus value of Prochaska-based stage-matched information on health-related cognitions and on Mediterranean nutrition behavior.

This study compares the effect of two interventions focussed on the promotion of Mediterranean nutrition behavior. The target groups are persons with three risk factors for development of cardiovascular disease. The study region is a socio-economically deprived area in the Netherlands. The first intervention consisted of three meetings in which the positive health effects of a Mediterranean diet were discussed in group sessions. In the additional intervention stage-matched information based on the Transtheoretical Model of behavior change was given. Both intervention groups were compared with a control group, which received only a printed leaflet with the Dutch nutritional guidelines. At baseline the three subgroups were comparable and after 16 weeks both intervention strategies resulted in significant changes in comparison with the control condition. For fish consumption, both strategies resulted in more positive attitudes, social norms, stronger intentions, more progress in stage of change and better nutritional intake. For fruit/vegetables consumption, the effects of both strategies were limited to stage of change and nutritional intake. Additional individually stage-matched tailored letters did not result in more progress on any of the dependent variables. We conclude that substantial nutritional behavior change can be achieved by interactive group education in socio-economically deprived population groups.