Your body can only digest so much protein as one time, but I think if you're taking 20 grams, three times a day through shakes, you should be okay. I believe my old gym teacher/trainer said that your body digests 20 grams of protein in approximately 3 hours. I'm not sure on every detail, I'm definitely not a nutritionist or any kind of trainer. Two a day should be alright. What you have suggested is what I do most of the time.