How long does a person need to be obese or even overweight before it makes him prone to illnesses like diabetes, cancer or heart disease?

Overweight Risks: Thank you for informing about “Never smoked or chewed Tobacco” and I commend you for your desire for Good Health. Excess weight is associated with increased incidence of Cardiovascular disease, Type 2 Diabetes mellitus (DM), Hypertension, Stroke, Osteoarthritis, Cancer. Duration to make someone prone to illness depends upon motivation to change Diet, exercise, and motivation for Health.