My Son eats sweet corn..... I have found buying him Green Giant corn is better than any of the others as the cheaper versions certainly have a higher carbohydrate content.
I would imgine fresh corn on the cob would be a lower still content but i could be wrong....
Nothing in theory is denied to diabetics, but of course some things are better than others
I personally dont eat it, or pasta, rice and other things but the only way is to eat to your meter - test and see what it does to you. If you are happy with what you see then choose to eat it
I like sweetcorn and have it tinned awa fresh. But I have yet to test it outside part of a meal.
A couple of points come to mind. It's good fibre for a start though nutritionally I'd read somewhere it is fairly low.
Second, I eat it as is without the usual butter drenching. What effect would that have I wonder.... 8)