Corresponding author e-mail: mistlber@sfu.ca 2009 marks the 30th anniversary of the first report that a circadian rhythm of food anticipatory activity persists in rats lacking a suprachiasmatic nucleus circadian pacemaker and light-dark cues (Stephan et al, 1979). Feeding time has since then been shown to regulate the phase of circadian oscillators in many brain regions and in most peripheral organs and tissues. The neural and molecular bases of food anticipatory behavioral rhythms remain to be clarified but progress has been made. The weight of evidence now favors the view that food anticipatory rhythms are mediated by a distributed neural system modulated by peripheral metabolic hormones. Distinct neural circuits may mediate anticipation of other rewards (mating, water, drugs) delivered on circadian schedules. The role of known clock genes in food-entrainable oscillations driving behavioral rhythms is contentious. The mechanisms by which rats and mice anticipate two or more daily meals, and link these with specific feeding places, are unclear. The objective of this presentation will be to review areas of consensus and controversy, and to identify important questions that remain to be addressed in circadian regulation of foraging and physiology. Publication History Article published online: 16 June 2026 © 2009. Brazilian Sleep Academy. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/) Thieme Revinter Publicações Ltda. Rua Rego Freitas, 175, loja 1, República, São Paulo, SP, CEP 01220-010, Brazil
R. Mistlberger (Thu,) studied this question.