Appetite and blood glucose profiles in humans after glycogen-depleting exercise.
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 micromol/l, insulin was 4.8 +/- 0.5 microU/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 (chi(2) = 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.
Melanson
K J
KJ
Department of Human Biology, Maastricht University, 6200 MD Maastricht, The Netherlands.
Westerterp-Plantenga
M S
MS
Campfield
L A
LA
Saris
W H
WH
D000328:Adult; D001066:Appetite / Q000502:physiology*; D001786:Blood Glucose / Q000502:physiology*; D015444:Exercise / Q000502:physiology* / Q000523:psychology; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005247:Feeding Behavior / Q000502:physiology; D006003:Glycogen / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D006815:Hunger / Q000187:drug effects; D008297:Male; D010809:Physical Fitness / Q000502:physiology
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D006003:Glycogen