Research paper
Zauner C, Schneeweiss B, Kranz A, Madl C, Ratheiser K, Kramer L, Roth E, Schneider B, Lenz K. “Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine.” American Journal of Clinical Nutrition, 2000; 71(6):1511-1515. DOI: 10.1093/ajcn/71.6.1511
Why we cite it
Provides direct empirical evidence that short-term fasting increases resting energy expenditure rather than decreasing it, a rise the paper’s conclusion describes as ”accompanied by an increase in plasma norepinephrine” (Spearman correlation mean 0.49). Only the title reads that as cause (”as a result of”). Scope: 11 healthy lean subjects across an 84-hour starvation period, REE rising significantly from 3.97 to 4.53 kJ/min between day 1 and day 3. The paper’s own Background is worth keeping beside the finding: ”Data obtained are conflicting and research has failed to provide conclusive results.” It bears against a simple ”starvation mode” account of short fasts, within the duration it measured. (Corrected 2026-09-10: this paragraph said the paper ”identifies the norepinephrine mechanism”, where its conclusion says ”accompanied by”, and that it ”helps explain the alertness many people report”, where alert occurs nowhere in the paper.)
About the author
Dr. Christian Zauner is a professor of internal medicine at the Medical University of Vienna, where he heads the Medical Intensive Care Unit and the outpatient clinic for nutrition medicine in the Department of Gastroenterology and Hepatology.