A Systematic Review of the Effects of Low-Carbohydrate Diet on Athletic Physical Performance Parameters

Abstract

A low-carbohydrate diet (LCD) or ketogenic diet is commonly used by individuals who want to achieve ketosis, which can boost fat metabolism, increase insulin sensitivity, and reduce blood sugar spikes. However, many athletes are hesitant to utilize a diet that specifically restricts the intake of carbohydrates, an important source of energy for physical activity. Athletes usually adopt a high-carbohydrate or high-protein diet, depending on their goals. This review aims to examine the evidence for the impact of an LCD on athletes' aerobic, anaerobic, and upper and lower body strength performance. A systematic review of original studies was conducted for articles indexed in PubMed that utilized an LCD in athletes and reported athletic performance values. A total of 19 studies were included in the final synthesis. An LCD may aid in maintaining or increasing upper and lower body strength. However, this type of diet provides no consistent benefit and may even negatively impact some measures of aerobic and anaerobic performance. Taken together, no strong evidence indicates the benefit of an LCD on athletic performance. Athletes wishing to modify their diet for improved performance should consider possible diets with specific training and performance goals in mind.

Keywords: aerobic performance; athletic performance; ketogenic diet; low-carbohydrate high-fat diet; lower body strength; strength.

Figure 1. PRISMA flow diagram

Process for the literature search, eligibility, and selection for including studies in the systematic review. PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses, LCHF: low-carbohydrate, high-fat

Figure 2. Risk of bias in studies included in the analysis

Studies included in the systematic review were assessed for risk of bias across seven domains. An overall risk of bias for each study is shown in the last column.