Humans need to obtain nutrients from foods in order to survive and be healthy. The requirements of energy and nutrients are different due to differences in race, age, sex, and physical activity level. People living in different places take nutrients from different kinds of food; therefore, nutrition is a cultural biological process rather than a simple physiological and biochemical process. Food intake can directly influence one's biological function through life, as its results are on a biological level. When people eat, the process can be influenced by economic, politics, culture, and many other factors.
