These days it is easier for diabetics to avoid specific foods, as the worst foods for diabetics are the same foods doctors advise all patients to eat sparingly. Living with diabetes means successfully controlling glucose levels by consciously sticking to a diet that avoids certain foods that are generally high in fat and sugar. If you stick to the right diet, you'll find a normal, long life without serious adverse effects of diabetes.
Dressings and Butters
Both salad dressings and butters are high in fat. When your body processes large amounts of fat, it throws off the blood's glucose levels. Even avoid margarine and oil and vinegar as these will trigger unnatural blood glucose levels. Beware of spreads and dips as well, such as mayonnaise, cream cheese and mayonnaise-based sauces.
Oily Meats and Vegetables
Avoid fatty, oily meats---such as bacon and chorizo---and vegetables---such as olives and avocado. These items add huge numbers of calories, fats and sodium to your diet and will undoubtedly throw off glucose levels. Instead eat lean meats and fresh, leafy vegetables.
Sweets, in general
Cake, ice cream, syrups and doughnuts are just a few of the multitudes of sweets that you should never eat as these will throw off glucose levels faster than anything. Read nutrition labels carefully because many processed food items also include large amounts of sugar. Now there are numerous sugar-free sweet options sold in major grocery stores that you can eat to satisfy that sweet tooth, and some actually taste pretty good.
For substitution suggestions, the web site eatright.org offers an extensive guide to foods OK for those with diabetes.