Oh, and over at Marvel, one of the Mighty Thor's three Asgardian best buds (I've forgotten his name) was pretty hefty, IIRC. And Wonder Woman's orignal sidekick Etta Candy was plump by 1940s standards, though I don't think she had any superpowers. I think there have been a number of fat sidekicks/best friends/etc.

Hmm. Nexus went through a "fat Elvis" period, but it was a symptom of him being Deeply Troubled.