Comparing the Effects of Glucose-Fructose versus Glucose on the Oxidation Rate: A Systematic Review and Meta-Analysis

Zahra Gohari  Dezfuli; Minoo Hasan  Rashedi; Fatemeh  Naeini; Sakineh  Shab-Bidar; Mohammadhossein  Pourgharib-Shahi; Xueying  Zhang; Elaheh  Dehghani; Kurosh  Djafarian

doi:10.18502/ijph.v54i4.18411

Zahra Gohari Dezfuli Sports Medicine Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
Minoo Hasan Rashedi Sports Medicine Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
Fatemeh Naeini Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
Sakineh Shab-Bidar Department of Community Nutrition, School of Nutritional Science and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
Mohammadhossein Pourgharib-Shahi Sports Medicine Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
Xueying Zhang Shenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
Elaheh Dehghani Sports Medicine Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
Kurosh Djafarian Sports Medicine Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/ijph.v54i4.18411

Keywords: Carbohydrate; Endurance exercise; Oxidation rate; Performance

Abstract

Background: Numerous studies have aimed to compare the effects of glucose (Glu) consumption with those of glucose-fructose (Glu-Fru) consumption on oxidation rates during exercise. However, divergent outcomes have surfaced due to variations in exercise protocols and concurrent substance ingestion, leading to a lack of consensus. This systematic review and meta-analysis investigated the comparative effects of Glu and Glu-Fru on total carbohydrate oxidation, endogenous carbohydrate oxidation, exogenous carbohydrate oxidation, and total fat oxidation rates during exercise.

Methods: A systematic search of PubMed, Scopus, and Web of Science databases up to February 2023. The search yielded 14 randomized controlled trials involving 125 endurance athletes.

Results: The meta-analyses revealed that Glu supplementation significantly increased total carbohydrate oxidation (WMD: 0.21 g/min) compared to Glu-Fru. Endogenous carbohydrate oxidation significantly increased with Glu (WMD: -0.12), while Glu-Fru led to increased exogenous carbohydrate oxidation (WMD: 0.27 g/min). Total fat oxidation decreased with Glu-Fru (WMD: -0.06 g/min).

Conclusion: By investigating athletic nutrition complexities, our findings shed light on metabolic responses to Glu-Fru versus Glu supplementation. Tailoring hydration strategies, athletes should select an optimal Glu-Fru to Glu ratio for maximal oxidation and enhanced performance. Future research could explore dose-response relationships for optimal metabolic benefits during exercise.