Consensus Document of the Spanish Nutrition Society (SEÑ) on Nutritional Strategies in Sports.

Juan Mielgo-Ayuso, Adrián Macho-González, Natalia Úbeda, Antonio Jesús Sánchez-Oliver, María Martínez-Ferrán, Diego Fernández-Lázaro, Raquel Aparicio-Ugarriza, Enrique Roche, Marcela González-Gross

Journal: Nutrients 2025;17(24):

PMID: 41470807

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Abstract

Introduction: Nutrition plays a fundamental role in sports performance by influencing energy availability, recovery, and training adaptation. In recent years, different dietary strategies have gained popularity among athletes, although the evidence supporting their efficacy is inconsistent. Objective: This consensus document, developed under the auspices of the Spanish Society of Nutrition, aims to provide a critical overview of the most relevant nutritional strategies currently used in sports and to offer evidence-based practical recommendations for both professional and recreational athletes, coaches, and health professionals. Methods: A narrative review was conducted following standardized scientific procedures by a multidisciplinary panel of experts. The analyzed strategies included high-carbohydrate, low-carbohydrate, ketogenic, intermittent fasting, plant-based, Paleolithic, and carbohydrate periodization diets. Each strategy was assessed based on its physiological rationale, evidence of performance in endurance, strength/power, sprint, aesthetic, weight category, and team sports, practical applications, and potential risks. Results: The available evidence shows that no single dietary strategy can be universally recommended for all athletes. High carbohydrate availability remains the most consistent approach for sustaining performance in endurance and high-intensity efforts. Low-carbohydrate and ketogenic diets enhance fat oxidation but often compromise exercise economy at competitive intensity levels. Intermittent fasting may improve body composition and metabolic health; however, it requires careful adaptation. Well-planned plant-based diets can support performance, although attention to certain nutrients (e.g., B12, iron, and omega-3) is essential. Paleolithic diets improve metabolic parameters but show limited direct evidence of athletic performance. Carbohydrate periodization is a promising tool for combining metabolic adaptations with competitive demands. Conclusions: Nutritional strategies should be individualized according to the athlete's sport, training phase, and personal context. Professional guidance is crucial for minimizing risks and optimizing benefits. Further well-designed, long-term studies on athletes are needed to resolve the current controversies.

Address: Faculty of Health Sciences, University of Burgos (UBU), 09001 Burgos, Spain.; Advanced Research in Integrative Physiology for Life Research Group (IAFIV), University of Burgos (UBU), 09001 Burgos, Spain.; Working Group on Nutrition for Exercise and Sport, Spanish Nutrition Society (SEÑ), 28010 Madrid, Spain.; Working Group on Nutrition for Exercise and Sport, Spanish Nutrition Society (SEÑ), 28010 Madrid, Spain.; Nutrition and Food Science Department (Nutrition), Pharmacy School, Complutense University of Madrid, 28040 Madrid, Spain.; AFUSAN Research Group, Sanitary Research Institute of the San Carlos Clinical Hospital (IdISSC), 28040 Madrid, Spain.; Working Group on Nutrition for Exercise and Sport, Spanish Nutrition Society (SEÑ), 28010 Madrid, Spain.; Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad San Pablo CEU, CEU Universities, Urbanización Montepríncipe, Boadilla del Monte, 28660 Madrid, Spain.; Working Group on Nutrition for Exercise and Sport, Spanish Nutrition Society (SEÑ), 28010 Madrid, Spain.; Departamento de Motricidad Humana y Rendimiento Deportivo, Universidad de Sevilla, 41013 Sevilla, Spain.; Working Group on Nutrition for Exercise and Sport, Spanish Nutrition Society (SEÑ), 28010 Madrid, Spain.; Area of Histology, Faculty of Health Sciences, University of Valladolid, 42004 Soria, Spain.; Neurobiology Research Group, University of Valladolid, 47005 Valladolid, Spain.; Facultad de Ciencias Jurídicas, Educación y Humanidades, Universidad Europea de Madrid, Campus de Villaviciosa de Odón, Calle Tajo s/n, Villaviciosa de Odón, 28670 Madrid, Spain.; ImFINE Research Group, Department of Health and Human Performance, Universidad Politécnica de Madrid, 28040 Madrid, Spain.; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain.; Working Group on Nutrition for Exercise and Sport, Spanish Nutrition Society (SEÑ), 28010 Madrid, Spain.; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain.; Department of Applied Biology-Nutrition, Institute of Bioengineering, University Miguel Hernández, 03202 Elche, Spain.; Alicante Institute for Health and Biomedical Research (ISABIAL), 03010 Alicante, Spain.; ImFINE Research Group, Department of Health and Human Performance, Universidad Politécnica de Madrid, 28040 Madrid, Spain.; CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain.; Spanish Nutrition Society (SEÑ), 28010 Madrid, Spain.

DOI: 10.3390/nu17243862

MeSH Terms: Humans, Sports Nutritional Physiological Phenomena, Athletic Performance, Spain, Consensus, Athletes, Sports, Dietary Carbohydrates, Diet, Fasting