In this editorial by Carol A Seymour and Kevin Whelan (22 May, pp 1364-5) reference 3 was wrongly attributed to Andres T; it should have been attributed to Blei AT. Moreover, Seymour and Whelan's reference to this article implied that Blei was recommending the dietary restriction mentioned; in fact they meant only to emphasise that a positive nitrogen balance benefits subjects, which is a point that Blei made in the reference cited.