I am assuming that you are using the newer version of FD. I couldn't figure out how to print them in that version either. BUT if you switch to FD Classic by clicking the "Classic" button at the top right of the screen, you will find a "print" button at the bottom of your log. Try that until someone smarter than me can tell us how to do it in the new version.
I used to print mine out pretty regularly to show my diet Doc.
2.5 years, 45 pounds later... 128ish pounds