I think: not sure but almost sure, that Type 1 is inherited/passed down through your family tree. If there is a family history of it, then you're more likely to get it. There is a way to 'manage' it, but there is no going back to change the problem. Once you have it, you have it. At least this is my understanding as my great-grandmother died from it at the age of 35 yo.

Type 2 is a lifestyle problem with being Overweight as the number 1 cause. Usually controlling your weight from eating too much sugars, starches and carbs usually control or rid you of the problem. Which means all the potato chips, snack cakes and cookies, ice cream, soda pop, potatoes cooked in any fashion, a lot of beans, breads, pastas and such should be cut out, cut down and/or eaten only occasionally or a spoonful during a more meat and veggies setting. I find that if you fill your plate full of mainly green and colorful veggies along with a meat, you are full and need none of the starches listed above. However, once a craving hits, just eat a small portion to satiate your craving and push yourself away from the table.