Christopher D Byrne1, Gianluca Perseghin2. 1. Nutrition and Metabolism, Faculty of Medicine, Institute of Developmental Sciences (IDS), MP887, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK; Southampton National Institute for Health Research Biomedical Research Centre, University Hospital Southampton, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK. Electronic address: c.d.byrne@soton.ac.uk. 2. Department of Medicine and Surgery, Università degli Studi di Milano Bicocca, Milan, Italy; Department of Medicine and Rehabilitation, Unit of Metabolic Medicine, Policlinico di Monza, Monza, Italy.