I am professor in Health Communication at the department of Health Promotion, Maastricht University, The Netherlands. In my academic research one of my core activities entails understanding health behavior and integrating various insights from different models. As a result the I-Change Model was developed, which should not be considered as a final model, but work in progress. In several projects in various countries we are applying, testing and refining this model for a range of different health behavior domains at the micro and macro level, such as smoking, alcohol, physical activity, nutrition, early detection of cancer, diabetes type 2, copd, (sexual) violence, and health policies.