Yeah, what I really meant was "pre-prediabetes." Because temporally what's called prediabetes usually occurs after being overweight too. If there is a physiological switch that, once triggered, leads to diabetes and also causes obesity, then it would also explain the odds-ratio but it would not be obesity causing diabetes.
"pre-diabetes" is a condition where insulin resistance is present but blood glucose levels don't meet the threshold for a type II diabetes diagnosis.