Effects of Japanese Diet on Post-Exercise Glycogen Recovery in Mice Skeletal Muscle and Liver.

The diet consumed by most Japanese people, which contains high amounts of carbohydrate and low levels of fat compared with the Western-style diet (WD), has been considered an effective diet for promoting glycogen recovery after exercise. However, there is no direct evidence to support this general belief, because no studies have examined the effect of whole, actually cooked Japanese-style diet (JD) on post-exercise glycogen replenishment. In this study, we comparatively examined the effects of a cooked typical JD and WD on glycogen accumulation in mouse skeletal muscle and liver after acute exercise. One-week menus (total 21 meals) of the JD and WD were reproduced based on national nutrition surveys in Japan and the U.S. All the meals were cooked, mixed and then fed to mice after acute 60-min running exercise. After the 4-h recovery period, mice given the JD had significantly higher muscle and liver glycogen concentrations than those fed the isoenergetic WD. Furthermore, even after the 24-h recovery period, the JD-fed mice also had significantly higher muscle glycogen concentration than the isoenergetic WD-fed group. Compared with the mice fed a WD, the JD-fed mice showed significantly higher plasma insulin level during the 4-h but not the 24-h recovery period. These results suggest that both short- and long-term feeding of the JD promote post-exercise muscle glycogen recovery compared to the WD, possibly through an insulin-dependent mechanism and non-insulin-dependent mechanism, respectively.