I wouldn't want to enforce an accounting mentality on eating.  I
say, if you're hungry, eat.  If you're still hungry, eat fat.  One day
when I was first starting out I was very, very hungry but only had four
blood oranges (they're slightly less sweet) and a can of tuna.  When I got
home I was still hungry, and made myself some bacon.  That did the trick.
Ultimately the individual is who has to decide the caloric intake.  I look
at it this way - there is no nutrition label on 1/2 the stuff we eat, so
why bother counting?