I don't think one day of anything is the end of the world, but I always make sure to get in my protein shake after every workout. It's only 90 calories for 20g of protein which doesn't ruin my whole day and I think it's important.
35 lbs. lost from 1/04/10 to 5/29/10
Size 14 to Size 8, 41-35-44 to 38-28-38
Maintaining Size 8, 39-29-39
Striving for functional fitness!