You'll be able to do that for a little while. You shouldn't skimp on breakfast though...it deserves as much respect as the other 4-5 meals a day you should be eating. I think it's good to get some low GI carbs in first thing in the morning. It should help with your energy for the rest of the day. Just adding oatmeal to your shake will help. Casein or whey will work in the morning if you're having protein in every meal (meals should be around 2.5 hours apart). I think it's most important to take in the casein at night.