Boromir was described as being a sturdy bloke wasn't he? And Hobbits are fat by nature and preference - Fatty Bolger must have been a really big lad then. Dwarves are also stocky, so I don't think Tolkien built anything into his works about people being fat or thin having any consequence much. Maybe if we imagine Elves as thin that's us as readers projecting ideas about 'perfection' onto them?
