I'd say 'with' is the most common preposition used in conjuction with 'obsessed', but I wouldn't necessarily call 'about' wrong. Prepositions, especially when dealing with the more 'popular' themes these days, like (food) obsessions, generally allow for multiple prepositions; and being obsessed 'about' food sounds just as normal as 'with'.* Like I could say: "Please, don't get all obsessed about it!" In the following context, I could even use ON properly: "I'm totally obsessing ON cute 'chibi' Anime characters." It may sound a bit too 'hip' for a person my age, LOL, but no one would deem it wrong, really. Especially American kids use 'on' a lot like that. -- * 'About' has a somewhat different connotation, though. Being obsessed 'about' something tends to denote the general subject at hand, whereas 'with' has a more clinical meaning. Example: "I'm obsessed about food." = I'm preoccupied with the subject matter food. "She's obsessed with food" = She's too fixated on the actual consumption of food. I should haste to say the distinction between the two is all but absolute; it's more that the former tends to lean one way, and the latter the other.

Hello, Both the prepositions 'with' and 'about' can be used with the verb 'obsess'. Compare: 1- Obsess WITH: If you are obsessed WITH something, it completely fills your mind (in a way that is not normal) so that you cannot think of anything else: 'She's greatly obsessed with her appearance.' 'He's obsessed with computer games.' 'People are so obsessed with image, being skinny and things like that.' 2- Obsess ABOUT: If you are OBSESSING about something, you are always talking or worrying about it, especially when this annoys other people: 'He's obsessing about food.' 'They obsess about money.' 'Do you obsess about money?' So the past participle 'obsessed' in the first 3 examples is used as an adjective to talk about someone who likes something or thinks of something in a way that is not normal. However, the word 'obsess' in the next 3 examples is used as a verb to mean ' always talk or worry about something, especially when this annoys other people.'

Personally I'd never say "obsessed about" something. In my opinion, "about" is NOT the correct preposition to use in this example in American English. I've seen "obsessed about" used in Indian-English. Maybe its used in British English (can someone from the UK weigh in on this?) In American English we'd normally say "obsessed with" something. The meaning should be the same regardless of which preposition is used or which preposition is correct. Although, to my ears, obsessed *about* would be slightly less intense than obsessed *with*