Going out to dinner when you're vegan usually translates to an enormous plate of pasta; unfortunately, that's as creative as many restaurants get. Consuming an entire bowl of noodles every once in a while is fine, but don't make it a habit just because you're not eating meat. Pasta is high in calories and carbs, which means eating it often can lead to weight gain.
When you do eat pasta, whether it's at a restaurant or your own kitchen table, go for the more nutritious whole wheat variety, but realize there's so much more to vegan meals than pasta. Think outside the box and experiment with entrée recipes that showcase tofu, tempeh, seitan, lentils, whole grains like quinoa and barley, and roasted veggies. Many restaurants are starting to experiment with these ingredients, so look for places that offer more than a bowl of spaghetti.