The present invention provides for a novel lipokine, C16:1n7-palmitoleate, which also serves as a biomarker for metabolic status. More specifically, a low concentration of C16:1n7-palmitoleate in the free fatty acid component of the serum indicates a risk of metabolic disease, and that de novo lipogenesis should be stimulated. Additionally, administering C16:1n7-palmitoleate to a subject (via nutraceutical or other means), positively impacts lipid metabolism.