Research paper
Cahill GF Jr. Fuel metabolism in starvation. Annual Review of Nutrition. 2006;26:1-22. doi:10.1146/annurev.nutr.26.061505.111258
Why we cite it
A review of human fuel metabolism during starvation synthesizing decades of the author's own research — which is the fact that gives it standing, and is checkable. (Previously "the definitive review", corrected 2026-09-02, card 6NM98H.) Establishes the central role of beta-hydroxybutyrate in brain fuel during fasting and documents the metabolic transitions (free fatty acids, glycerol, glucose, lactate, pyruvate) that sustain life without food intake. This paper is the foundational reference for understanding why fasting is physiologically safe.
About the author
George F. Cahill Jr. (1927–2012) was an American physician-scientist at Harvard Medical School and the Joslin Diabetes Center, where he served as research director (1962–1978). A pioneer in human metabolic research, he conducted landmark studies on fuel metabolism during prolonged starvation, establishing how the body transitions from glucose to ketone metabolism. He was also a Howard Hughes Medical Institute researcher, advisory board member, and vice president. Author or co-author of nearly 200 scientific publications.
DOI: 10.1146/annurev.nutr.26.061505.111258 · PubMed 16848698 · Publisher