There are four main categories of food that cannot be eaten when blood sugar is high: 1. foods with high oil content, that is, fried and deep-fried foods, such as fried scallops, fried tenderloin, fried potato chips, etc. 2. roots and starchy foods, such as potatoes, roots, yams, groundnuts, etc. 3. foods with high sugar content, especially fruits, including watermelon, apples, bananas, oranges, etc. 4. 4, porridge, such as starchy porridge, corn paste or rotten noodles, etc.