The effective resolution of major nutrition problems requires interdisciplinary and intersectoral approaches, and is of public interest; therefore a "public action" approach such as that described by Drèze and Sen in "Hunger and Public Action" is proposed to help define the key contributors required. Public action comprises action taken by members of the public, not merely for the public. It could include actions of very diverse public institutions, both collaborative and adversarial, in addition to those of government and the private sector, provided they can influence communities, families, and individuals, are taken in collaboration, and share a common purpose. Conditions of effective collaboration, including the need to arrive at a broad and shared understanding of the problem, are highlighted. The potentially critical role of academic and research institutions is briefly reviewed, and it is suggested that they may not be fully contributing to the necessary advances in broadening the understanding of nutrition problems.