Endurance athletes may implement rigid dietary strategies, such as the ketogenic diet (KD), to improve performance. The effect of the KD on appetite remains unclear in endurance athletes. This study analyzed the effects of a KD, a high-carbohydrate diet (HCD), and habitual diet (HD) on objective and subjective measures of appetite in trained cyclists and triathletes, and hypothesized that the KD would result in greater objective and subjective appetite suppression. Six participants consumed the KD and HCD for 2-weeks each, in a random order, following their HD. Fasting appetite measures were collected after 2-weeks on each diet. Postprandial appetite measures were collected following consumption of a ketogenic meal after the KD, high-carbohydrate meal after the HCD, and standard American/Western meal after the HD. Fasting total ghrelin (GHR) was lower and glucagon-like peptide-1 (GLP-1) and hunger were higher following the KD versus HD and HCD. Fasting insulin was not different. Mixed-effects model repeated measures analysis and effect sizes and 95% confidence intervals showed that postprandial GHR and insulin were lower and GLP-1 was higher following the ketogenic versus the standard and high-carbohydrate meals. Postprandial appetite ratings were not different across test meals. In conclusion, both fasting and postprandial concentrations of GHR were lower and GLP-1 were higher following the KD than the HC and HD, and postprandial insulin was lower on the KD. Subjective ratings of appetite did not correspond with the objective measures of appetite in trained competitive endurance athlete. More research is needed to confirm our findings.

耐力运动员可能会实施严格的饮食策略，例如生酮饮食 (KD)，以提高表现。KD 对耐力运动员食欲的影响仍不清楚。本研究分析了 KD、高碳水化合物饮食 (HCD) 和习惯性饮食 (HD) 对训练有素的自行车运动员和铁人三项运动员食欲的客观和主观测量的影响，并假设 KD 会导致更大的客观和主观食欲抑制。六名参与者在 HD 之后以随机顺序分别服用 KD 和 HCD 2 周。每次饮食 2 周后收集空腹食欲测量值。在 KD 后食用生酮餐、HCD 后食用高碳水化合物餐以及 HD 后食用标准美式/西方餐后，收集餐后食欲测量值。KD 与 HD 和 HCD 相比，空腹总生长素释放肽 (GHR) 较低，胰高血糖素样肽-1 (GLP-1) 和饥饿感较高。空腹胰岛素没有什么不同。混合效应模型重复测量分析和效应大小和 95% 置信区间显示，与标准和高碳水化合物膳食相比，生酮餐后餐后 GHR 和胰岛素较低，GLP-1 较高。餐后食欲评级在测试膳食中没有不同。总之，与 HC 和 HD 相比，KD 后空腹和餐后 GHR 浓度较低，GLP-1 较高，KD 后餐后胰岛素较低。食欲的主观评价与训练有素的竞技耐力运动员的客观食欲测量不相符。需要更多的研究来证实我们的发现。