Effects of rice diet and bread diet on plasma triglyceride, insulin and ghrelin level after endurance exercise

In this study, the effects of a rice diet and bread diet on plasma triglyceride, insulin and ghrelin levels during low-intensity endurance exercise and recovery were investigated. Ten male students randomly received 2 different treatments: the rice diet and bread diet. On the first day, the participants performed 2 hours of treadmill running with 6% uphill at 50% VO_2max after breakfast and then each consumed lunch and dinner. Blood samples were drawn 120 min before exercise and, right before exercise and, 60 min and 120 min after the start of exercise. On the second day, blood samples were drawn prior to breakfast, immediately after breakfast and, 60 min, 120 min, and 180 min after breakfast with no exercise treatment. Plasma triglyceride, ghrelin, glucose, and insulin levels were not significantly different between the two treatment groups on the first day. In addition, there was no difference in the carbohydrate and fat oxidation rate between the two treatments groups. However, plasma triglyceride levels in subjects that received the rice diet were significantly reduced by 14% when compared to subjects that received the bread diet at 180 min after consuming the breakfast diet on the second day. Ghrelin levels were significantly higher for subjects that received the rice diet than subjects that were given the bread diet. However, insulin in participants that consumed the rice diet was significantly lower than those that received the bread diet at 60 min and 120 min after consumption of the breakfast diet on the second day. Glucose levels in the subjects that were given the rice diet were significantly reduced by 10.3% when compared with participants that received the bread diet at 60 min. Therefore, the results of the study showed that a rice diet may be more effective in preventing cardiovascular diseases than a bread diet when combined with exercise.