Waking up at 6 am, 32-year-old Nischith S goes for a brisk walk. This is followed by a nutritious, high-protein breakfast. His meal comprises good quantities of fruits and vegetables. Before he is back home from work, Nischith works out regularly at the gym. But what shocked him was when doctors told him that his giddiness during the day, hunger pangs and frequent urge to urinate were early signs of a disorder — diabetes mellitus. “I wonder how it hit me. I have an active lifestyle and my body mass index is normal. Is this because my father also had diabetes?” Diabetologists admit there are no clear answers to these questions yet, but they are close to identifying a set of genes that make Indians genetically more predisposed to the disease. “We don’t yet know what percentage of diabetes is due to genetic factors or how much of a role a rapidly changing lifestyle and environment plays. But with growing incidence, we see genes play a vital role,” said Madras Diabetes Rese...