To help people prevent weight gain, the Netherlands Nutrition Centre initiated the ‘balance intervention’, which promotes moderation of food intake and/or increased physical activity in response to occasions of overeating. The aim of this study was to determine whether intervention materials were appreciated, encouraged information seeking and increased motivation and caloric compensatory behaviours. A three-group randomized trial with pre-intervention measures (n=963, response 86%) and post-intervention measures (n=857) using electronic questionnaires was conducted among participants aged 25–40 years, recruited from an Internet research panel. The first group received a printed brochure and electronic newsletters (print group), the second group was exposed to radio advertisements (radio group) and the third group was the control group. Multiple regression analyses were used to investigate the impact of the materials on self-reported prevalence of overeating, attitudes, perceived behavioural control, intentions and compensatory behaviours. At follow-up, we found significantly more positive attitudes, intentions and dietary action in the print and radio groups. However, participants who received the radio advertisement had a significantly lower perceived behavioural control. No effects were found on the prevalence of overeating. The results indicate that the intervention materials have potential for increasing people's attitudes, motivation and self-reported behaviour actions, with a possible negative side-effect on perceived behavioural control.