Can caffeine prevent diabetes?

im sure i read somewhere that if you drink alot of coffee it can make u feel lethargic,hungry and irratable as the caffeine makes the body probuce insulin so lowering blood sugar levels, turing the glucose into glycogen to be stored, hence less sugar in the blood and u feel hungy and tired.

so surley it follows that if you lik to eating alot of sweets and cakes then to prevent type 2 diabetes u must drink alot of sugar free coke and coffee when you eat alot of sweets, so blood sugar lebvels will stay stable??