Diabetes mellitus represents a public health problem because of its growing prevalence and the enormous costs for its treatment and complications. There are numerous risk factors for diabetes mellitus development but the most important ones are the modifiable factors. In Bihor County the prevalence of obesity and sedentary behaviour in the population of newly diagnosed patients are increased compared to their prevalence in the population without diabetes. Promotion of healthy eating habits and increased physical effort are the most important measures to prevent diabetes mellitus type 2, which accounts for 90-95% of total diabetes cases. Public health programs that bring together physicians, nutritionists, teachers and target groups (children, young people, obese and overweight people)must be initiated in general population from an early age and maintained in order to promote the adherence to a healthy lifestyle.