The second meal phenomenon is associated with enhanced muscle glycogen storage in humans

A. Jovanovic (1) , E. Leverton , B. Solanky , B. Ravikumar , J. E. M. Snaar , P. G. Morris , R. Taylor

1 Institute of Cellular Medicine

Background: The rise in blood glucose after lunch is less if breakfast has been eaten. The metabolic basis of this second meal phenomenon remains uncertain. We hypothesized that storage of ingested glucose as glycogen could be responsible during the post meal suppression of plasma FFA. Objective: To determine the metabolic basis of the second meal phenomenon. Design: Healthy subjects were studied on two separate days, with breakfast and without breakfast in random order. We studied metabolic changes after a standardized test lunch labeled with 3 g of 13C- labeled (99%) glucose. Changes in postprandial muscle glycogen storage were measured using 13C magnetic resonance spectroscopy. Results: The rise in plasma glucose after lunch was significantly less if breakfast had been taken (0.9±0.3 vs. 3.2±0.3 mmol/l, with and without breakfast respectively; p<0.001) despite comparable insulin responses. Pre-lunch FFA were suppressed after breakfast (0.13 ± 0.03 vs. 0.51 ± 0.04 mmol/l) and levels correlated positively with the maximum glucose rise after lunch (r=0.62; p=0.001). The increase in muscle glycogen signal was greater 5 hours after lunch on the breakfast day (103.2 ± 20.7 vs. 47.6 ± 12.4 Units; p<0.007) and correlated negatively with plasma FFA concentrations before lunch (r=-0.48; p<0.05). Conclusion: The second meal effect is associated with priming of muscle glycogen synthesis consequent upon sustained suppression of plasma FFA concentrations.

Mots clés: Medicine

A. Jovanovic, E. Leverton, B. Solanky, B. Ravikumar, J. E. M. Snaar, et al.. The second meal phenomenon is associated with enhanced muscle glycogen storage in humans. Clinical Science, 2009, 117 (3), pp.119-127. ⟨10.1042/CS20080542⟩. ⟨hal-00496946⟩