Ingested food not only affects human physical health, but also plays an important role in a development and maintenance of cognitive performance and intelectual activity throughout the whole life. Both aspects equally contribute to human wellbeing . The review of research results concerning relation between food and diet, its components and their relation to each other – and some psychological processes has been presented. In particular it covers the effect of food on early brain development and intelectual potential of a child, direct effect of the meal and its composition on cognitive and psychomotor performance in children, adults and elderly, as well as the influence on affective status of humans.