Overdoing it on greasy, fried foods can lead to weight gain and wreak havoc on your blood sugar. French fries, potato chips, and doughnuts are particularly bad choices for diabetics because they're made with carb-heavy, starchy ingredients, which can cause blood glucose levels to shoot up. Fried foods soak up tons of oil, leading to lots of extra calories — and some, like fried chicken and many fried appetizers, are coated in breading which increases the calorie count even more. Many fried foods are also laden with unhealthy trans fats because they've been deep-fried in hydrogenated oils, which will raise your bad cholesterol and increase your risk of heart disease. Whether you already have diabetes or are working to prevent it, no amount of trans fats can be safely incorporated into your diet, so it's best to check labels and keep hydrogenated oils far from your plate.