Uncomfortable situation at work

Lucy • Mother to a beautiful baby boy born 30/10/16 💙
Hi ladies, i apologise I don't know if I'm being stupid I don't really want to talk to anyone I know about this but it's really been getting to me. 
I'm very slim however eat a lot and have always been pretty happy with my shape. (Of course just the odd bits here & there!) However recently guys at work have noticed how much I eat and have made comments on my body shape "Your boyfriend has bigger tits that you. You have the body of a 12 year old boy." They laugh and apologise however me being me have taken these comments to heart, these are guys I normally get along with now I've been feeling really paranoid about my shape and even the girls I work with were laughing.. 
I know that this was probably a joke but I didn't see it that way now feel uncomfortable to eat like I normally do or join in with work banter as it comes back round to the fact I have no ass or boobs. I don't need men to make me feel good about myself but the fact they've said comments like that just made me feel crap 😔
Just wanted to ask am I being stupid? How would you handle this situation? It's honestly getting to me a lot more than it should do any help is appreciated xxx