Stevenson E, Williams C, Nute M, Humphrey L, Witard O
School of Psychology and Sports Sciences, Northumbria University, Newcastle upon Tyne, UK.
Eur J Clin Nutr. 2008 May;62(5):608-16. doi: 10.1038/sj.ejcn.1602759. Epub 2007 Apr 18.
To investigate whether the 'overnight second-meal effect' results in altered substrate oxidation during the postprandial period following breakfast and subsequent sub-maximal exercise in women.
SUBJECTS/METHODS: Seven recreationally active women were recruited for the study. In each trial, participants were provided with their evening meal on day 1, which was composed of either high glycaemic index (HGI) or low glycaemic index (LGI) carbohydrates (CHO). On day 2, participants were provided with a standard HGI breakfast and then performed a 60 min run at 65% [V.]O(2 max) 3 h later.
The incremental area under the curve (IAUC) for plasma glucose concentrations during the postprandial period following breakfast was greater in the HGI trial compared to the LGI trial (P<0.01). Similarly, the IAUC for serum insulin concentrations was greater in the HGI trial than the LGI trial (P<0.05). No differences in plasma free-fatty acids (FFA) or plasma glycerol concentrations were found between trials during the postprandial period. During subsequent exercise, there were no significant differences in substrate metabolism.
The glycaemic index of an evening meal does not alter substrate oxidation at rest following breakfast or during subsequent submaximal exercise in women. This study provides further evidence for the overnight second-meal effect on glycaemic responses following a LGI mixed evening meal.
研究“隔夜第二餐效应”是否会导致女性早餐后及随后次最大强度运动期间的餐后底物氧化发生改变。
受试者/方法：招募了7名有休闲运动习惯的女性参与本研究。在每次试验中，第1天为参与者提供晚餐，晚餐由高血糖指数（HGI）或低血糖指数（LGI）碳水化合物（CHO）组成。第2天，为参与者提供标准的HGI早餐，然后3小时后进行60分钟、强度为最大摄氧量（[V.]O(2 max)）65%的跑步运动。
与LGI试验相比，HGI试验中早餐后餐后期间血浆葡萄糖浓度的曲线下增量面积（IAUC）更大（P<0.01）。同样，HGI试验中血清胰岛素浓度的IAUC高于LGI试验（P<0.05）。餐后期间各试验之间血浆游离脂肪酸（FFA）或血浆甘油浓度无差异。在随后的运动过程中，底物代谢无显著差异。
晚餐的血糖指数不会改变女性早餐后休息时或随后次最大强度运动期间的底物氧化。本研究为LGI混合晚餐后隔夜第二餐对血糖反应的影响提供了进一步的证据。
