As a consequence, the interest of scientists and policy makers is now focused on characterizing the optimal dietary patterns and patterns of prenatal and postnatal size/growth. This paper briefly reviews: (1) evidence on the infant size/growth and early nutrition on disease in adulthood, (2) methodological issues associated with current scientific approaches that evaluate the impact of early nutrition/growth on later outcomes, (3) recent regulations and guidelines developed by various expert groups or scientific organizations, and (4) ways to solve some unresolved issues.