PhD: The Impact of Dietary Practices on Female Athletes' Health and Performance – Comparative Analysis of Keto, Plant-Based, Intermittent Fasting, and Western Diets Kingston University in United Kingdom

This PhD project at Kingston University investigates the impact of four distinct dietary practices—ketogenic, plant-based, intermittent fasting, and Western diets—on the health and performance of female athletes. Female athletes face unique physiological challenges, particularly regarding energy availability, hormonal balance, and menstrual health. The research aims to provide a comprehensive comparative analysis of how these dietary approaches affect performance, recovery, and overall wellbeing, with a special focus on preventing Relative Energy Deficiency in Sport (RED S) and its associated risks, such as menstrual dysfunction and reduced bone density.

The study will examine the benefits and limitations of each diet. Plant-based diets, while rich in nutrients like magnesium and omega-3 fatty acids, may pose challenges in achieving adequate protein, iron, and vitamin B12 intake, increasing the risk of low energy availability and RED S. Ketogenic diets, characterized by high fat and low carbohydrate intake, may support fat loss and cognitive focus but can disrupt hormonal function and menstrual health if energy requirements are not met. Intermittent fasting, with its defined eating windows, may further challenge hormonal regulation, particularly affecting hormones essential for menstrual regularity. The Western diet, typically higher in refined sugars and processed foods, can predispose athletes to metabolic disturbances if not managed carefully, but can support performance when energy and nutrient quality are controlled.

The project will employ a mixed methods research design, combining a randomized controlled trial with qualitative inquiry. Female athletes will be allocated to one of the dietary patterns under dietitian supervision. Quantitative assessments will include energy availability, hormonal profiles, menstrual tracking, performance testing, and measures of mood, health, and wellbeing at baseline and post-intervention. A subsample will undergo detailed laboratory assessments to examine metabolic function and acute physiological responses to training. Semi-structured interviews will explore athletes' lived experiences and perceptions of each dietary approach, providing practical insights for individualized nutrition strategies.

The findings aim to inform evidence-based, individualized dietary recommendations for female athletes, emphasizing the importance of aligning nutrition with training load, physiological demands, and long-term health. This project addresses key gaps in sports nutrition research and has the potential to improve dietary guidelines and health outcomes for female athletes across various sporting disciplines.

Funding is available through the Kingston University Graduate School studentships competition for October 2026 entry. Applicants should apply as 'self-funded'; this status will be updated if a studentship is awarded. The application deadline is March 4, 2026. For more information and to apply, visit the Kingston University Research Degrees portal.