The dietary transition from traditional to commercial foods and a decrease in physical activity (PA) have impacted the health of the First Nations people of Quebec (Canada), resulting in many suffering from multiple chronic diseases. This study had two objectives: (1) to examine eating and PA behaviors among First Nations peoples in urban areas and (2) to explore the associated health representations. To achieve these objectives, a mixed-methods approach, including a questionnaire (n = 32) and a semi-structured interview (n = 14), was used to explore the participants’ lifestyle profiles and health experiences. The questionnaire focused on the eating and PA behaviors of First Nations people and their underlying motivations. At the same time, the interviews investigated their health views on diet and PA behaviors based on the conceptual framework of health and its determinants. According to the participants, health is the autonomy to live without pain by maintaining a balance between physical and psychological aspects, eating healthy and exercising. Family and work influence participants’ PA and eating behaviors. Exploring First Nations people’s beliefs and perceptions and the motivations underlying their health behaviors could help encourage the maintenance of a healthy lifestyle despite multiple chronic health conditions.