Coordinating energy supply with use is critical for survival and is tightly regulated. There is growing evidence that the oestrogen-related receptors (ERRs), a family of orphan nuclear receptors, play key roles in this regulation, ERRγ being the most recently discovered member of this family. Hepatic expression and activity of ERRγ is induced by fasting and repressed in response to feeding. Work reported by Kim and colleagues (DOI: 10.1007/s00125-014-3366-x ) dissects the mechanism for the latter observation. Taken together with prior studies by this group and others, there is emerging evidence that this protein helps coordinate metabolism and may be a potential therapeutic target.