Prof Lim is trained in General Medicine and Endocrinology with a subspecialty interest in Diabetology. He is currently a Senior Consultant at Khoo Teck Puat Hospital's Diabetes Centre (overseeing the Diabetic Kidney Disease Clinic) and Department of General Medicine.

Prof Lim is also the Clinical Director of the Clinical Research Unit. He was a Clinical Research Fellow at the Joslin Diabetes Center, Boston, USA in 1997/98. He earned a PhD in Genetic Epidemiology from the National University of Singapore (NUS) in 2009.

He holds Professor appointments at the National University of Singapore and Lee Kong Chian School of Medicine. Prof Lim's research interests include obesity, diabetic kidney disease, monogenic diabetes and genetic epidemiology.