Obesity is a multifactorial disorder affected by multiple genetic and environmental factors, in particular nutrients, and their interrelationships. Increasing knowledge of the genes and molecules involved in the development of obesity is paving the way for new methods of obesity control. In this sense, Nutrigenomics--which represents a new approach in nutrition research that joints the application of powerful functional genomics technologies, bioinformatics and molecular biology with more traditional methodologies--may orientate the design and development of new functional foods for obesity, based on the scientific knowledge of the impact of specific nutrients on the mammalian body weight control system and their mechanisms of action.