This paper aims to emphasize the risks of obesity and physical inactivity, knowing that an unhealthy lifestyle based on sedentariness, a chaotic rhythm of work programmes and sleeping hours, and inappropriate food ingestion in terms of quality and regularity of meals is a major factor in disturbing the individual's well-being. Evidence shows that physical activity can be used as a preventive measure or a secondary care standard for chronic health issues related to obesity, such as cardiovascular disease, type 2 diabetes mellitus, colon cancer and stroke. Recent studies are focused on the efficiency of different obesity management strategies in order to avoid obesity-related comorbidities. Physical activity fosters the mental and functional balance of the individual, ensures good body weight control, improves and contributes to maintaining the health status, satisfies the need for movement, responds to the need for group affiliation and social interaction, and provides contexts for personal communication. Despite the people's awareness of the statistics, their involvement in physical activity is low. Physical exercise programmes should be approached as medical prescriptions for an optimal state of health, being a medicine with no negative effect if properly applied, but with many health benefits. Changes in a person's lifestyle related to physical exercise, diet and harmful leisure result from the congruence of several political, economic, ideological and educational factors.