Prevalence of diabetes has increased for both genders across all age groups from 1990 to 2016:

Source: The increasing burden of diabetes and variations among the states of India: the Global Burden of Disease Study 1990-2016, Lancet Global Health, 2018.

States of Kerela, Tamil Nadu and Punjab have the highest prevalence of diabetes (> 10.5%). The same states have among the highest rates of obesity and heart disease too.

Source: The increasing burden of diabetes and variations among the states of India: the Global Burden of Disease Study 1990-2016, Lancet Global Health, 2018.

The legend (color codes) for the infographic below and above are identical:

Source: The increasing burden of diabetes and variations among the states of India: the Global Burden of Disease Study 1990-2016, Lancet Global Health, 2018.

In 2015, the CARRS study recruited n = 16,288 subjects aged >= 20 years from 3 big metro cities: Delhi, Chennai and Karachi.

What did they find?

73% (diabetes: 25%, prediabetes: 48%) in Delhi
61% (diabetes: 23%, prediabetes: 38%) in Chennai
47% (diabetes: 16%, prediabetes: 31%) in Karachi

These numbers are mindboggling.