Regulatory functions of glycogen stores and blood glucose on human appetite, particularly relating to exercise, are not fully understood. Ten men (age 20–31 yr) performed glycogen-depleting exercise in an evening, ate a low-carbohydrate dinner, and stayed overnight in the laboratory. The next day, blood glucose was monitored continuously for 517 ± 23 (SE) min. Subjects had access to high-fat and high-carbohydrate foods after baseline glucose and respiratory quotient were determined. In the afternoon, 1 h of moderate exercise was performed. Baseline respiratory quotient was 0.748 ± 0.008, plasma free fatty acids were 677 ± 123 μmol/l, insulin was 4.8 ± 0.5 μU/ml, and leptin was 1.9 ± 0.3 ng/ml. Postabsorptively, 8 of 10 meals were initiated during stability in blood glucose. Postprandially, the association between meal initiation and blood glucose declines became significant (χ2 = 7.82). During moderate exercise, blood glucose initially decreased but recovered before completion. When the glycogen buffer is depleted, meal initiation can occur during blood glucose stability; the relationship between blood glucose declines and meal initiation reestablishes with refeeding.
- glucostatic theory
- glycogenostatic theory
- food intake regulation
Address for reprint requests and other correspondence: M. S. Westerterp-Plantenga, Dept. of Human Biology, Maastricht Univ., P.O. Box 616, 6200 MD Maastricht, The Netherlands (E-mail:).
This work was supported by grants from Hoffmann-La Roche, Inc., and Maastricht-Wageningen MENU-VLAG.
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- Copyright © 1999 the American Physiological Society