School of Biomedical Sciences, Kent State University, Kent, Ohio, USA.
Department of Biological Sciences, Kent State University, Kent, Ohio, USA.
Exp Physiol. 2021 Aug;106(8):1731-1742. doi: 10.1113/EP089434. Epub 2021 Jul 7.
What is the central question of this study? How does intrinsic aerobic capacity impact weight loss with 50% daily caloric restriction and alternate-day fasting? What is the main finding and its importance? Intermittent fasting is effective for weight loss in rats with low fitness, which highlights the importance of how intermittent fasting interacts with aerobic fitness.
Recent interest has focused on the benefits of time-restricted feeding strategies, including intermittent fasting, for weight loss. It is not yet known whether intermittent fasting is more effective than daily caloric restriction at stimulating weight loss and how each is subject to individual differences. Here, rat models of leanness and obesity, artificially selected for intrinsically high (HCR) and low (LCR) aerobic capacity, were subjected to intermittent fasting and 50% calorie restrictive diets in two separate experiments using male rats. The lean, high-fitness HCR and obesity-prone, low-fitness LCR rats underwent 50% caloric restriction while body weight and composition were monitored. The low-fitness LCR rats were better able to retain lean mass than the high-fitness HCR rats, without significantly different proportional loss of weight or fat. In a separate experiment using intermittent fasting in male HCR and LCR rats, alternate-day fasting induced significantly greater loss of weight and fat mass in LCR compared with HCR rats, although the HCR rats had a more marked reduction in ad libitum daily food intake. Altogether, this suggests that intermittent fasting is an effective weight-loss strategy for those with low intrinsic aerobic fitness; however, direct comparison of caloric restriction and intermittent fasting is warranted to determine any differential effects on energy expenditure in lean and obesity-prone phenotypes.
这项研究的核心问题是什么？内在有氧能力如何影响 50%日常热量限制和隔日禁食的体重减轻？主要发现及其重要性是什么？间歇性禁食对低适应能力大鼠的体重减轻有效，这突出了间歇性禁食与有氧适应能力相互作用的重要性。
最近人们对限时喂养策略（包括间歇性禁食）在减肥方面的益处产生了兴趣。目前尚不清楚间歇性禁食是否比每日热量限制更能有效地促进体重减轻，以及它们各自受到哪些个体差异的影响。在这里，通过对内在高（HCR）和低（LCR）有氧能力的人工选择，肥胖倾向的瘦大鼠和肥胖大鼠模型在两个独立的雄性大鼠实验中分别接受了间歇性禁食和 50%热量限制饮食。瘦的高适应能力 HCR 和肥胖易感性低适应能力 LCR 大鼠接受 50%热量限制，同时监测体重和组成。低适应能力 LCR 大鼠比高适应能力 HCR 大鼠更能保持瘦体重，而体重和脂肪的比例没有明显差异。在另一个使用雄性 HCR 和 LCR 大鼠进行间歇性禁食的实验中，隔日禁食导致 LCR 大鼠体重和脂肪质量明显减轻，而 HCR 大鼠的自由摄食日食量减少更为明显。总之，这表明间歇性禁食是低内在有氧能力人群的有效减肥策略；然而，需要对热量限制和间歇性禁食进行直接比较，以确定它们对瘦和肥胖倾向表型的能量消耗有何不同影响。
