Health is an important and unavoidable issue for all people. In order to maintain and improve health in the medium to long term, we must improve our daily dietary habits. However, it is difficult to scientifically define a “better diet.” This is because individual foods contain a myriad of ingredients, and it is difficult to grasp the overall picture of how these ingredients contribute to health. In addition, obesity is a major enemy of health, but much remains unexplored regarding its prevention and mechanisms. Therefore, research on the mechanisms of obesity and the elucidation of various food component functions will continue to grow in importance. In this chapter, we introduce food ingredients and biological components that contribute to the prevention of obesity, focusing on our recent research.