Infant and child growth and health: standards, principles, practice.

John Waterlow, who celebrated his 90th birthday in June last year, is one of the most influential nutrition scientists of all time. I also know from family experience and peer testimony that he is a generous mentor and inspiring leader. The 1985 FAO/WHO/UNU report specifying human energy and protein requirements, the product of a consultation which he chaired, is (remarkably) still current in the case of protein, and is a masterpiece of elegant and lucid argument. As professor at the London School of Hygiene and Tropical Medicine between 1970 and 1981, he built up his department ‘on four legs: metabolism; clinical nutrition; public health nutrition; and nutrition policy’. To his great disappointment, the basic and applied parts of the department were cleaved after his retirement. Recently he had kind words to say about the three-dimensional biological, social and environmental new nutrition science. So I respond to his letter on past, present and future infant and child growth standardswith deep respect. His attitude to science is encapsulated in the final sentence of the 1985 report, surely written by him. ‘If the present judgements are thought to be inappropriate, then it is up to the user, or the community of users, to offer more appropriate judgements. No longer can we bypass the question “Requirements for what?”.’ This contribution addresses his courteous challenge.