In the turbulent years surrounding the Partition of India, a young boy named Jasbir Singh Bajaj arrived in Delhi with his family from Lahore. Born on 26 September 1936 to Sardar Makhan Singh Bajaj, a respected homeopath, and Jaswant Kaur, he grew up in an atmosphere that valued learning and service. His elder sister, the writer Ajeet Cour, would later become a celebrated literary figure; the household encouraged both intellectual curiosity and quiet discipline.

Jasbir excelled at school and entered Amritsar Medical College, graduating with distinction in 1958. He completed his MD in Medicine from Punjab University in 1962 and then travelled to Britain as a Commonwealth Scholar. At the Royal Postgraduate Medical School in London and the University of Newcastle upon Tyne he trained in endocrinology and metabolic medicine, returning to India with a deep understanding of diabetes and hormonal disorders at a time when specialised knowledge in these fields was still scarce.

In 1966 he joined the faculty of the All India Institute of Medical Sciences in New Delhi. By 1979 he had become Professor and Head of the Department of Medicine. Students remembered him as a teacher of rare clarity and presence. During one teaching round a young resident hesitated over a complex diabetic case.

“Sir, the blood sugar is high, but the patient is undernourished. How do we classify this?”

Professor Bajaj looked at the notes, then at the patient, and spoke with quiet precision.

“Look carefully. This is not the diabetes described in Western textbooks alone. Malnutrition changes the picture. We must recognise it, name it, and treat the whole person—not only the number on the chart.”

His research on the entero-hypothalamo-insular axis, insulin dynamics, and the metabolic effects of protein-calorie malnutrition led to the recognition of a distinct category—malnutrition-related diabetes mellitus—later incorporated into the international classification of diabetes. International colleagues came to refer to aspects of this work as Bajaj’s syndrome.

He served as Honorary Physician to the President of India for two terms and as Consultant Physician to the Prime Minister. From 1991 to 1998 he was Member (Health) of the Planning Commission with the rank of Minister of State, helping shape national policies on population, nutrition, medical education and public health. In 1985 he became the first scientist from outside Europe and the United States to be elected President of the International Diabetes Federation; on completing his term he was named Honorary President for life.

The nation recognised his work with successive Padma awards: Padma Shri in 1981, Padma Bhushan in 1982, and Padma Vibhushan in 2009—making him one of the very few physicians to receive all three. The Karolinska Institute conferred upon him an honorary doctorate, and he was elected Fellow of the Royal Colleges of Physicians of London and Edinburgh as well as of the National Academy of Medical Sciences.

On 8 January 2019 Professor Jasbir Singh Bajaj passed away in Gurugram. He left behind a body of research that reshaped the understanding of diabetes in developing countries, a generation of students who carried his standards forward, and a model of the physician who moves seamlessly between the bedside, the laboratory and the realm of public policy. In the long story of Indian medicine he stands as a rare figure: a clinician-scientist whose work reached from the individual patient to the health of an entire nation.