The Effect of a Ketogenic Low-Carbohydrate, High-Fat Diet on Aerobic Capacity and Exercise Performance in Endurance Athletes: A Systematic Review and Meta-Analysis.

Jingguo Cao,Sulin Cheng,Xiuqiang Wang,Siman Lei

doi:10.3390/nu13082896

Jingguo Cao, Sulin Cheng + Show 2 more

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https://doi.org/10.3390/nu13082896

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Abstract

A low-carbohydrate, high-fat (LCHF) diet has been proposed to enhance the fat utilization of muscle and the aerobic capacity of endurance athletes, thereby improving their exercise performance. However, it remains uncertain how the macronutrient intake shift from carbohydrate to fat affects endurance exercise training and performance. This study performed a systematic review and meta-analysis to explore the effects of a ketogenic low-carbohydrate, high-fat (K-LCHF) diet on aerobic capacity and exercise performance among endurance athletes. Searches were carried out in five electronic databases, and we followed the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. The search included studies using an LCHF diet as an intervention protocol and compared data on factors such as maximum oxygen uptake (VO2max) and rating of perceived exertion (RPE) from the graded exercise test. In this case, 10 studies met the criteria and were included in the meta-analysis. We did not find a significant effect of K-LCHF diet interventions on VO2max, time to exhaustion, HRmax or RPE. However, a significant overall effect in the substrate oxidation response to respiratory exchange rate was observed. The meta-analysis showed that K-LCHF diets did not affect aerobic capacity and exercise performance. Therefore, high-quality interventions of a K-LCHF diet are needed to illustrate its effect on various endurance training programs.

Highlights

The low-carbohydrate, high-fat (LCHF) diet has become popular as a treatment for excess weight, epilepsy and type 2 diabetes in recent decades [1,2,3]
After reviewing the limited literature on the K-LCHF diet in endurance athletes, 10 eligible studies were included in the meta-analysis
We found that body mass was significantly decreased after the K-LCHF diet intervention endurance athletes

Summary

Introduction

The low-carbohydrate, high-fat (LCHF) diet has become popular as a treatment for excess weight, epilepsy and type 2 diabetes in recent decades [1,2,3]. The first LCHF diet study to optimize fat oxidation in endurance athletes was conducted in 1983 by Phinney et al [4]. He spotlighted various mechanisms to boost endurance performance by promoting a shift in substrate utilization to enhance physiological training benefits by adopting the LCHF diet. The concept of improving athletic performance by adapting to a high-fat diet was reconsidered after a series of studies failed to prove significant benefits [5]. With the resurgence in popularity of “Paleolithic” and “ketogenic” diets, there has been renewed interest in the LCHF diet [6]

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