[3][5][6] He has stayed with AIIMS ever since and is a professor and the head of the department of endocrinology, metabolism and diabetes at the institution.
[3][5] He has been the national co-ordinator for Action in Diabetes and Vascular Diseases (ADVANCE),[6] a study conducted by The George Institute for Global Health, Australia for combating the risks of diabetes and prevent it becoming a global epidemic[7] and has been a member of the steering committee of Center for Cardio-metabolic Risk Reduction in South Asia (CARRS) Trial funded by the National Heart Lung and Blood Institute.
[6] Tandon is a former vice-president of the National Academy of Sciences, India[8] and a president and the incumbent general secretary of the Indian Society for Bone and Mineral Research.
[6][12] His research findings have been published in several national and international journals,[5][6][13][14][15] PubMed listing 454 of them in their online repository.
[16] He has also featured in the news for the pituitary tumor surgery of the then tallest woman in the world, Siddiqa Parveen.