Good question!
My answer is...go by the book and use the size of YOUR palm or fist for portions. (The exceptions would be eggwhites or cottage cheese which are 'fluffy').
Don't get hung up on calories...the beauty of BFL (one of them anyway) is the fact that we DON'T count calories. From what I've seen, people who start BFL and begin to count calories instead of palm/fist end up underfeeding themselves...and don't make progress - remember you have to feed your muscles to help them grow - and the muscles will burn fat 24 hours a day, 7 days a week! Believe me, it WORKS. As long as you're eating clean (the list is on page 83 of the book) and measuring palm/fist, you'll be just fine.