Health systems around the world are currently facing a challenge to fight the tremendous growth of non-transmissible chronic diseases (NTCD), especially cardiovascular diseases. These diseases can be prevented if adoption of healthy habits and lifestyles are adopted by people, specifically by increasing their physical activity and having a healthy nutrition. The objective of this article is to describe the modeling process of a context-aware system with the purpose of supporting interventions to promote physical activity and healthy nutrition, duly adjusted to the characteristics of the user's context. The main results of this article are: a) a classification model of health context and a context adaptability and personalization process model; b) a proposal of a context model for a context-aware system, which supports the promotion of physical activity and healthy nutrition; c) a reference architecture and a prototype of the system developed on such architecture, which consists of a mobile application supported by NFC and GPS technologies; and d) an evaluation of the solution usability.