Prof. Dr. Luc van Loon

Biography

Professor van Loon was appointed Professor of Nutrition and Exercise at Maastricht University in The Netherlands in 2010. Luc has an international research standing in the area of skeletal muscle metabolism, has published well over 530 peer-reviewed articles (more than 32.000 citations) achieving an H-index of 95. He was in the top 1% of cross-field (nutrition and physiology) highly-cited scholars globally for 2023. Current research in his laboratory focuses on the skeletal muscle adaptive response to physical (in)activity, and the impact of nutritional and pharmacological interventions to modulate metabolism in both health and disease. The latter are investigated on a whole-body, tissue, and cellular level, with skeletal muscle as the main tissue of interest. He is active in various media to translate research findings to the general public, highlighting the impact of nutrition and physical activity to support performance and health.

Presentation of summary

Skeletal muscle protein is constantly being synthesized and broken down, with a turnover rate of about 1-2% per day. The rate of skeletal muscle protein synthesis is regulated by two main metabolic stimuli, food intake and physical activity. Food intake, or more specifically protein ingestion, directly elevates muscle protein synthesis rates. The dietary protein derived essential amino acids act as signaling molecules activating anabolic pathways and provide precursors for muscle protein synthesis. Ingestion of a meal-like amount of dietary protein elevates muscle protein synthesis rates for several hours, providing evidence that ‘you are what you just ate’. When food is ingested after a bout of physical activity the post-prandial muscle protein synthetic response is augmented, with higher muscle protein synthesis rates sustained over a more prolonged period of time. In other words, when you ingest protein following a bout of physical activity ‘you become even more of what you just ate’. In contrast, when protein is ingested following a period of inactivity the post-prandial muscle protein synthetic response is blunted, coined anabolic resistance. Therefore, disuse makes you ‘become less of what you just ate’. These concepts play a key role in the prevention and management of muscle loss in both health and disease.