Diabetes is a problem with blood sugar regulation which is primarily accomplished via insulin regulation. if you have a problem regulating something it is almost always best to minimize both the amount and variability of use of that thing.
The long answer is, in our time of great abundance, the most common version of type 2 diabetes by a mile is the one where blood sugar is always elevated because fat cells have stopped responding as well to insulin and insulin is also always elevated. Elevated insulin stops energy release from fat cells and keeps fat cells absorbing glucose and storing it as fat for as long as they can until they get large, unresponsive and usually start releasing inflammatory chemicals (aka they start causing you a bad time) thats when insulin jacks up further and once jacking insulin up stops working you now get classified as having type 2 diabetes. so in so far as our fat cells are not highly responsive to insulin, sugar is bad and inso far as sugar contributes to your fat cells getting unresponsive to insulin over time it's bad too (barring a famine that being at maximum fatness will help you survive).
The long answer is, in our time of great abundance, the most common version of type 2 diabetes by a mile is the one where blood sugar is always elevated because fat cells have stopped responding as well to insulin and insulin is also always elevated. Elevated insulin stops energy release from fat cells and keeps fat cells absorbing glucose and storing it as fat for as long as they can until they get large, unresponsive and usually start releasing inflammatory chemicals (aka they start causing you a bad time) thats when insulin jacks up further and once jacking insulin up stops working you now get classified as having type 2 diabetes. so in so far as our fat cells are not highly responsive to insulin, sugar is bad and inso far as sugar contributes to your fat cells getting unresponsive to insulin over time it's bad too (barring a famine that being at maximum fatness will help you survive).