Just Bento

i'm very small and am trying to keep my bentos around 200 calories.
does anyone have any suggestions for bento boxes that are around 200-250 ml, without looking extremely childish?
oh and any good recipes would help.

Just stumbled onto a stainless steel box for sale for $10 online!
http://www.zoombabygear.com/item_575/Stainless-Steel-Container.htm
My cubic inches to ml says it's around 850, but that's including the domed lid, and approximate. Good for sandwiches and bulky fruit and salads, probably. But cheap! They also have a 12oz stainless steel bottle with nipple cap for babies, but it says a sport cap is available, I guess on request. Also $10.
http://www.zoombabygear.com/item_576/Stainless-Steel-Sippy-Cup.htm

I found this link off of WIRED Gadget Labs today and figured the Bento crowd would love it.

http://blog.wired.com/gadgets/2009/02/moben-stylish-s.html

The concept, from designer Alex Cheong, is modular and would be fully dishwasher safe.