The aliens were probably poisonous to humans. Since they had no qualms about rendering them for fuel, they probably checked to see if they were edible. There's a line about having gone without food for 2-3 weeks, so I'm assuming the aliens must have been toxic. During noon hour in my local Co-op, you can buy them already baked. There's a really long fanfic I've been following where Seven's holodeck persona and Chakotay's persona from the WW2 scenario slept together (unknown to either Seven or Chakotay consciously) when the Hirogens invaded the ship. Awhile later, Seven discovered herself pregnant, and the result is an 84-chapter (and counting) fanfic where Seven and Chakotay are married, with a daughter. The latest chapter has them deciding to adopt and raise the Borg baby that everybody on the show forgot about. So now they are married, with children. And the Borg kids. Dunno if the author will change that to let the Borg kids stay; I actually liked Mezotti and was disappointed when she was written out of the show.