Lies and dammed nutritional science. googled the opposite to the article and this popped up immediately:
Some studies suggest that drinking coffee — whether caffeinated and decaffeinated — may actually reduce your risk of developing type 2 diabetes. If you already have diabetes, however, the impact of caffeine on insulin action may be associated with higher or lower blood sugar levels.
Doesn't say if the blood sugar rise was due to the muffin they ate with their coffee or if they stopped at Starbucks for one of their Grande spiced pumpkin lattes (the adult equivalent of a milkshake!).
Or if those feeling tired because they are suffering from undiagnosed diabetes might drink coffee to help them through.
Coffee is my drug of choice so I am biased to disagree with this contention so on its side I can see that it raises the stress hormones which could cause a rise in blood sugar but the ideas that it 'causes type 2' is non sensical!