You shouldn't really feel that full unless you're using like 20ius of slin. The goal is to eat the least ammount of carbs without going hypo. So, your pwo meal should start with 10g of dex per iu and slowly over the next few workouts you can lower it closer to 6 or 7g/iu. Then ppwo I eat about half as many carbs as pwo. If you just eat a shiitload of carbs you're going to get very fat.