Energy Deficit, Muscle Adaptation, and the Truth About Low Energy Availability with José Areta

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This week on the podcast, Mikki speaks to returning guest Associate Professor José Areta to unpack one of the most debated topics in sports nutrition: energy availability, and what really happens when intake drops below demand.

José takes a clear, physiology-first approach to explaining what energy availability actually means, why it has become such a dominant concept in exercise science, and whether the current narrative has become overly black-and-white. They explore his recent study examining the effects of a short, aggressive energy deficit, including what happens not just at a whole-body level, but deep within muscle tissue itself.

In this conversation, they discuss the hormonal and metabolic responses to rapid weight loss, surprising findings around mitochondrial protein synthesis, and what changes in muscle and connective tissue might actually represent. José also reframes energy deficit as a biological stressor — one that may be adaptive in the right context — and challenges assumptions around how common and harmful low energy availability truly is.

This is a nuanced, evidence-driven discussion that cuts through the noise and offers a more balanced perspective on energy deficit, performance, and long-term health.

José L Areta currently works as an associate professor in Sports Nutrition and Metabolism at the School of Sport and Exercise Sciences at LJMU.

José examines how nutrition interacts with exercise to shape both performance and health, with a focus on macronutrient timing and composition, the role of supplements in optimisation, and the hormonal and metabolic responses to energy restriction.

José can be found at:https://profiles.ljmu.ac.uk/13460-jose-areta

Paper: https://pubmed.ncbi.nlm.nih.gov/41182317/

Previous appearance https://podcast.mikkiwilliden.com/124

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