If you smoke, quit.
Smoking increases the risk of developing diabetes, and once you have it, smoking makes every problem and complication associated with diabetes even worse. Smoking raises blood-glucose levels, constricts blood vessels, and causes inflammation, and smokers have an increased risk of kidney disease, nerve damage, blood-vessel damage, and foot and leg infections. Note that many people gain weight after quitting smoking because they try to satisfy their nicotine cravings by eating more — a particularly dangerous strategy for people with diabetes. Therefore, it's super-important to quit smoking, if you smoke — and to be mindful of your food intake as you kick the bad habit.