Department of Life Sciences, Manchester Metropolitan University, UK.
Department of Life Sciences, Manchester Metropolitan University, UK.
Appetite. 2019 Dec 1;143:104411. doi: 10.1016/j.appet.2019.104411. Epub 2019 Aug 21.
Growing evidence suggests circadian rhythms, nutrition and metabolism are intimately linked. Intermittent fasting (IMF) has become an increasingly popular intervention for metabolic health and combining IMF with exercise may lead to benefits for weight management. However, little is known about the diurnal variation of fasted exercise. This study aimed to investigate the diurnal influences on gastric emptying rate (GER), metabolic responses, and appetite to fasted and non-fasted exercise. Twelve healthy males completed four 45 min walks in a randomised order. Walks were completed in the morning (AM) and evening (PM) and either fasted (FASTED) or after consumption of a standardised meal (FED). GER of a semi-solid lunch was subsequently measured for 2 h using the C breath test. Blood glucose concentration, substrate utilisation, and ratings of appetite were measured throughout. Energy intake was also assessed for the following 24 h. GER T was slower in PM-FASTED compared to AM-FASTED, AM-FED, and PM-FED (75 ± 18 min vs. 63 ± 14 min, P = 0.001, vs. 65 ± 10 min, P = 0.028 and vs. 67 ± 16 min, P = 0.007). Blood glucose concentration was greater in the FED trials in comparison to the FASTED trials pre-lunch (P < 0.05). Fat oxidation was greater throughout exercise in both FASTED trials compared to FED, and remained higher in FASTED trials than fed trials post-exercise until 30 min post-lunch ingestion (all P < 0.05). No differences were found for appetite post-lunch (P > 0.05) or 24 h post-energy intake (P = 0.476). These findings suggest that evening fasted exercise results in delayed GER, without changes in appetite. No compensatory effects were observed for appetite, and 24 h post-energy intake for both fasted exercise trials, therefore, increased fat oxidation holds positive implications for weight management.
越来越多的证据表明，昼夜节律、营养和新陈代谢密切相关。间歇性禁食（IMF）已成为促进代谢健康的一种越来越受欢迎的干预手段，将 IMF 与运动相结合可能有助于控制体重。然而，对于空腹运动的昼夜变化知之甚少。本研究旨在探讨空腹和非空腹运动的昼夜影响对胃排空率（GER）、代谢反应和食欲的影响。12 名健康男性以随机顺序完成 4 次 45 分钟的步行。步行分别在早上（AM）和晚上（PM）进行，并且要么空腹（FASTED），要么在进食标准餐（FED）后进行。随后使用 C 呼吸测试在 2 小时内测量半固体午餐的 GER。整个过程中测量血糖浓度、底物利用情况和食欲评分。还评估了接下来 24 小时的能量摄入。与 AM-FASTED、AM-FED 和 PM-FED 相比，PM-FASTED 的 GER T 较慢（75±18 分钟 vs. 63±14 分钟，P=0.001，vs. 65±10 分钟，P=0.028 和 vs. 67±16 分钟，P=0.007）。与 FASTED 试验相比，FED 试验在午餐前的血糖浓度更高（P<0.05）。与 FED 相比，在 FASTED 试验中，整个运动过程中的脂肪氧化率更高，并且在运动后直到午餐后 30 分钟，在 FASTED 试验中仍高于进食试验（所有 P<0.05）。午餐后食欲无差异（P>0.05）或 24 小时后能量摄入（P=0.476）无差异。这些发现表明，晚上进行空腹运动可导致 GER 延迟，而不会改变食欲。对于食欲，以及两个空腹运动试验的 24 小时后能量摄入，没有观察到补偿效应，因此，增加脂肪氧化对体重管理具有积极意义。
