 After the second world war had ended, Platt became the head of a new research unit at the MRC, focusing on nutrition and Waterlow followed him and worked with the unit.During this time, Platt imprinted the a prediction on Waterlow that, "Nutrition will be the problem of the future".He was sent to the Caribbean in 1945 to investigate why large numbers of children there were dying and discovered that many had oedematous malnutrition and fatty livers, but was unsure why this was the case.