1 Carbs and sugar restriction is very important in type 2 diabetics. 2  Although the reduction of carbs should be discussed with a diabetic dietitian, a general rule is a diabetic should have no more than 20-60 grams of carbs per day, or even less if your blood sugar is constantly too high. 3  Eating carbs is like eating sugar. Although the reduction of carbs should be discussed with a diabetic dietitian, a general rule is a diabetic should have no more than 20-60 grams of carbs per day, or even less if your blood sugar is constantly too high. 2  Eating carbs is like eating sugar. 3  It will increase your blood sugar levels without a doubt.