Graduate School of Education, Chung-Ang University, Seoul 06974, Korea.
Sports Medicine and Science, Kyung Hee University, Gyeonggi-do 17104, Korea.
Int J Environ Res Public Health. 2021 Mar 12;18(6):2912. doi: 10.3390/ijerph18062912.
(1) Background: The purpose of the current meta-analysis was to investigate any positive or negative effects of ketogenic diets in athletes and provide an assessment of the size of these effects. (2) Methods: Databases were used to select relevant studies up to January 2021 regarding the effects of ketogenic diets in athletes. Inclusion criteria were as follows: data before and after ketogenic diet use, being randomized controlled trials and presenting ketogenic diets and assessments of ketone status. Study subjects were required to be professional athletes. Review studies, pilot studies, and studies in which non-athletes were included were excluded from this meta-analysis. The outcome effect sizes in these selected studies were calculated by using the standardized mean difference statistic. (3) Results: Eight studies were selected for this meta-analysis. Athletes who consumed the ketogenic diet had reduced body fat percentages, respiratory exchange rates, and increased total cholesterol compared to athletes who did not consume this diet. However, body mass index, cardiorespiratory fitness, heart rate, HDL cholesterol, glucose level, and insulin level were unaffected by the diet. (4) Conclusions: Ketogenic diets had a beneficial effect by decreasing body fat percentage, but athletes with high total cholesterol level need to be monitored when instituting a ketogenic diet. Our study sample size was limited; therefore, additional studies may be needed to confirm the current findings. Further studies need to be conducted on changes in LDL cholesterol, HDL cholesterol, total cholesterol and ratio of LDL to HDL cholesterol.
(1) 背景：本荟萃分析的目的是研究生酮饮食对运动员的任何积极或消极影响，并评估这些影响的大小。(2) 方法：使用数据库选择截至 2021 年 1 月有关运动员生酮饮食影响的相关研究。纳入标准如下：生酮饮食前后的数据、随机对照试验以及生酮饮食和酮体状态评估。研究对象必须是职业运动员。本荟萃分析排除了综述研究、试点研究和纳入非运动员的研究。从这些选定的研究中计算出的效应大小使用标准化均数差统计量。(3) 结果：本荟萃分析选择了 8 项研究。与不食用这种饮食的运动员相比，食用生酮饮食的运动员体脂百分比、呼吸交换率降低，总胆固醇增加。然而，饮食对体重指数、心肺适能、心率、高密度脂蛋白胆固醇、血糖水平和胰岛素水平没有影响。(4) 结论：生酮饮食通过降低体脂百分比产生有益效果，但当采用生酮饮食时，需要监测总胆固醇水平较高的运动员。我们的研究样本量有限；因此，可能需要进行更多的研究来证实目前的发现。需要进一步研究 LDL 胆固醇、HDL 胆固醇、总胆固醇和 LDL 与 HDL 胆固醇比值的变化。
