8 years old and 40 pounds--now that brings back memories of canoe trips about 10 years ago (my sons would have been 7 and 9 back then).  Yes, teenagers can be a real pain in the butt sometimes.   >:(  My 17 year-old football playing son is rarely home anymore....when I do see him in the morning, I get a couple grunts, a few belches and other bodily function noises, then a request for the keys and some money....when he comes home later, he empties the fridge, belches some more, but will actually talk in complete sentences instead of grunting...then he's off till the wee hours around midnight.  All in all a typical teenager, but of good character.  

The good news is, even though my boys eat alot more now, they're stronger than me and can carry the extra food and the heaviest of the packs on the trails...they've also become really good fishermen...all I really have left to do now is teach them how to cook!   :)