In this paper, we have proposed a user model for computer based drinking behavior change intervention and recommender systems. We discuss specific requirements of user modeling in health promotion and specifically alcohol interventions. We believe that making behavior change systems available pervasively may lead to better and sustainable results. Therefore, our proposed user model takes advantage of the target-behavior related features such as contextual features (e.g., social interactions, location, and time). The proposed user model uses well-validated questionnaires to capture target-behavior specific aspects. We also introduced approaches for enhancing users' experience in the model creation stage by using Embodied Conversational Agents(ECAs) and users' affective states.