Professor Tai is a clinician-scientist who researches metabolic diseases, including diabetes mellitus, obesity, dyslipidemia, and hypertension, and their links to coronary artery disease. He also investigates diabetes-related complications, particularly those affecting the eyes and kidneys. His research focuses on the varying risk factor levels among different ethnic groups in Singapore, particularly concerning insulin resistance and dyslipidemia. Additionally, he is interested in gene-environment interactions that influence lipid metabolism, insulin resistance, and atherosclerotic disease.