It's hard to not eat meat when in Central America, particular if you won't eat dairy. I don't know if you're missing much on dairy though, as I always found the milk sour tasting and the farmer's cheese nearly unpalatable. I would have offered up quesadillas and the like, but that's got cheese. There's a lot of fish on the Caribbean coast: lobster, conch, and whatever pez came from the ocean that day. There's not a lot of beef and even for meat eaters, I do not recommend the beef. Most of the food is based around chicken or pork. In Costa Rica some of the staples are patacones (fried plantains) and rice and beans, so if you don't mind eating a lot of that you'll be good. I'd recommend staying at a hostel or guesthouse with a kitchen and cooking for yourself. In the highlands of the countries it is easier to get green vegetables, but in the lowlands, while you'll have a great abundance of fruits, especially bananas, good veggies other than potatos and onions might be hard to come by. Some of the food on the Caribbean coast of Costa Rica was good, and the Caribbean spiny lobsters in Belize were amazing, but other than that, the food sucked far and wide until I reached Merida in the north east of the Mexican Yucatan.

Make sure to eat pineapple, rambutan (locally called momonchino), raw cacao (there is a tart membrane around the seeds), passion fruit and whatever else you can get your hands on in Costa Rica. Honduras has the best cantaloupe I have ever tasted. And enjoy the delicuious fruit shakes (batidos, licuados or agua fresca depending on the region) and ask for them "con agua" rather than "con leche" because you don't eat dairy.

Dude! The basic staple food of central america is Rice and Beans, no joke. You will be able to find that everywhere you go. There is also fried plantain. I don;t know whether you eat eggs, but eggs with vegies are also common. Tortillas are made of corn and are nice an thick. You'll be surprised how much non-meat dishes there are and of course there are fruits like papayas, and nanses. Corn also dude, you'll be able to find bbq corn or steamed corn on the cob.

good travels.