A high caloric intake in today's nutrition and a sedentary lifestyle are the main causes of the notable increase in obesity in our society. In turn, this results in an increase in associated pathologies, such as metabolic syndrome and diabetes type 2. In the present work we review most recent studies and programs, which are significant due to their sample size and geographical diversity. It clearly shows that changes in alimentation and lifestyles are an effective instrument for combatting or delaying the onset of these diseases. In this sense, prevention is also key to avoiding serious consequences related to diabetes and metabolic syndrome, which can affect the life of the population.