Lifestyle intervention studies have shown that the development of cardiometabolic diseases can be partly prevented or postponed by the combination of a healthy diet and physical activity. Cardiometabolic diseases and their risk factors are particularly prevalent among individuals with low socioeconomic status and some ethnic minorities, and therefore these groups especially may benefit from participating in lifestyle interventions. Although individuals with low socioeconomic status and ethnic minorities could potentially benefit from lifestyle interventions, it seems that these groups are often not successfully reached for such interventions. The overall aim of this thesis was therefore to study opportunities for, and the effectiveness of, lifestyle interventions to reduce the risk of cardiometabolic diseases, targeting individuals with low socioeconomic status of different ethnic origins. The studies in this thesis has shown that intensive combined lifestyle interventions, involving dietary counselling and sports lessons, can be effective in low socioeconomic status populations and identified possible adaptations to make lifestyle interventions more suitable for individuals with low socioeconomic status of Dutch, Turkish and Moroccan origin.