Man. I was forced to have nothing but juice and J-ello for a week and a half after a surgery. I think I lost around 15 pounds, too. I would assume that it would be near impossible to keep them off because I just gained it all back with my regular diet. Or maybe my "regular diet" is just excessive eating.

Nope, it's the same thing (over here anyway).
You guys say 'jelly' but you mean 'jam'.
We say 'jelly' and we mean 'jelly'.
I never did understand how Jello, which is a brand name (correct me if I'm wrong), usurped Jelly's position as the title for flavoured gelatin goop.
I'm even more confused about why *anyone* would call jam 'jelly'.

Jelly is a spread made from the juices of the fruit/veggie being used. Such as grape jelly, mint jelly, hot pepper jelly and so on. Jam on the other hand uses the whole fruit (minus stick bits and leaves of course). You see this with such things as strawberry jam.