Chair of Human Nutrition Human Nutrition at Glasgow University, UK, and a consultant physician at the Glasgow Royal Infirmary, UK.
Adjunct professor at the University of Otago, and visiting professor, University of Sydney.
Professor Lean has established the only academic department of Nutrition in a Scottish Medical School, with a ‘broad-focus’ strategy toward translational, integrative, research and teaching, encompassing the full range of scientific disciplines within Human Nutrition. Awards include Diabetes UK-Rank Prize Lecture (2014), Banting Memorial Lecture (2020),Tenovus Medal for Research (2017), Fellowship of the Scotland’s National Academy (Royal Society of Edinburgh) (2018). Professor Lean is currently the primary investigator on the largest research grant ever awarded by Diabetes UK, the Diabetes Remission Clinical Trial (DiRECT). He has published over 350 Original Research articles, and has an H-Index of 101. Outside of research he plays a fiddle and escapes to climb mountains whenever possible.
Normal endocrine systems maintain 24-hour blood glucose concentrations within the safe range for cell function and health, 3.5-8 mmol/l, across the entire range of human diet compositions. Minor differences in post-prandial glycaemia from dietary GI variations appear well tolerated within that range, but greater post-prandial glucose excursions and variability are problematic when there is diabetes, contributing to elevated HbA1c. In people without diabetes, protein glycation (eg HbA1c) is elevated with lower (not higher) carbohydrate intakes and higher fat intakes, by poor antioxidant intake, and in inflammatory states. People with T2D have limited adipose tissue fat-storage capacity, so excess body fat accumulates in ectopic organ sites, impairing functions. The DiRECT trial showed that weight loss >15kg removes the ectopic fat and restores non-diabetic state for 86% of early T2D. Later relapse of T2D is related to weight regain with raised liver and pancreas fat, and with elevated serum triglycerides, particularly palmitate.