Some healthy snacks for diabetics would be those that create a balance and don't create a big sugar jolt to the system. For example, while eating a serving of low-fat chocolate pudding as a snack could work well for non-diabetics, it may be too much sugar to eat at once for diabetics. Diabetics would probably be better off having it as a dessert after a meal instead.
Of course, sugar free pudding as a snack could be an option for diabetics. But, healthier balanced options would be low fat cheese and a piece of whole grain toast or some whole grain crackers. Carrot sticks or a few grapes could also work with that.
Since diabetics may need to eat more often that non-diabetics in order to maintain a more even blood sugar level, planning healthy snacks ahead and having them ready to grab is a great idea.
Leftovers can make great snacks! When you're putting leftover food away, prepare snacks and have them on the ready. For example, a little leftover roast or chicken and some leftover salad can be stuffed into a whole wheat wrap. A little canned tuna or salmon taken out from the lunch you're preparing can be mixed with plain nonfat yogurt and then eaten open face on a slice of whole wheat toast for a snack.