Dr. Liu's research is mainly concerned with the etiology of chronic diseases with special emphasis on identifying strategies for their prevention and control. His team has contributed to many studies of diverse populations around the world. This work has led to the identification and confirmation of several novel genetic, biochemical, dietary, and environmental risk factors and their interactions in the development of obesity, diabetes, and cardiovascular diseases. To date, Dr. Liu has published >400 peer-reviewed research papers, some of which are most frequently cited. In 2015, he was listed as one of the most highly cited scholars with an H-index>100. He has developed and taught 8 courses and directly supervised >100 trainees at Harvard, UCLA, and Brown, and delivered > 200 invited lectures worldwide.

Dr. Liu is an elected fellow of the American Heart Association (FAHA), American Society of Clinical Investigation (ASCI), American Epidemiological Society (AES), and a permanent member of the Epidemic Intelligence Service Alumni Association (EISAA). He has also served as a member or chair on committees/study sections/ advisory boards for federal and international agencies, including the National Institute of Health (NIH), the Centers for Disease Control and Prevention (CDC), the Chinese CDC, the Canadian Institutes of Health Research and Canadian Foundation for Innovation, the European Union, the British Medical Research Council (MRC), and the World Health Organization (WHO), providing consultations on issues related to pharmaceuticals, nutrition, and global health.