The effect of potatoes on prediabetes can depend on various factors. This includes the potato variety, cooking methods, portion size, and overall dietary context. Potatoes are naturally high in carbs, which can impact blood sugar levels. It's always better to seek a professional's opinion. The American Diabetes Association has recommended several helpful diets for preventing diabetes, such as Mediterranean-style, low-fat, low-carbohydrate eating plans and Dietary Approaches to Stop Hypertension (DASH).