The use of stimulants, an improperly composed diet, lack of exercise, metabolic and mental stress, as well as overweight increase the risk of periodontitis. These lifestyle choices have an (in)direct influence on the immune system and can initiate inflammatory reactions at the level of the periodontium. Ultimately, this increases the susceptibility to gingivitis and periodontitis. A complete diet in terms of macro- (proteins, omega-3 fatty acids) and micro-nutrients (vitamins), as well as physical activity and sufficient relaxation appear to be essential for a healthy periodontium. A healthy weight, but especially a waist circumference within the normal range, also contribute to a reduction in the risk of periodontitis: directly, through the release of pro-inflammatory cytokines via the adipocytes, and indirectly, through obesity-related disorders. An unhealthy lifestyle thus increases the susceptibility to periodontal disease. Lifestyle advice should therefore be part of periodontal care.