Insulin question and type 2 diabetes

How long can a type 2 diabetic take to need to prick insulin?

It does not have to need to prick insulin if it has a healthy eating, it maintains a correct weight, it does sports, in short, if it leads a healthy life, it does not necessarily have to end up putting insulin.

Thank you very much for your answer.

My grandfather died with 94 years and never needed insulin.
A totally strict life to control it: it is the best we can do.